6 Jim Tcl v0.78+ - reference manual for the Jim Tcl scripting language
15 jimsh [<scriptfile>|-]
16 jimsh -e '<immediate-script>'
22 * <<CommandIndex,Command Reference>>
23 * <<OperatorPrecedence,Operator Precedence>>
24 * <<BuiltinVariables, Builtin Variables>>
25 * <<BackslashSequences, Backslash Sequences>>
29 Jim Tcl is a small footprint reimplementation of the Tcl scripting language.
30 The core language engine is compatible with Tcl 8.5+, while implementing
31 a significant subset of the Tcl 8.6 command set, plus additional features
32 available only in Jim Tcl.
34 Some notable differences with Tcl 8.5/8.6 are:
36 1. Object-based I/O (aio), but with a Tcl-compatibility layer
37 2. I/O: Support for sockets and pipes including udp, unix domain sockets and IPv6
39 4. Support for references (`ref`/`getref`/`setref`) and garbage collection
40 5. Builtin dictionary type (`dict`) with some limitations compared to Tcl 8.6
41 6. `env` command to access environment variables
42 7. Operating system features: `os.fork`, `os.uptime`, `wait`, `signal`, `alarm`, `sleep`
43 8. Much better error reporting. `info stacktrace` as a replacement for '$errorInfo', '$errorCode'
44 9. Support for "static" variables in procedures
45 10. Threads and coroutines are not supported
46 11. Command and variable traces are not supported
47 12. Built-in command line editing
48 13. Expression shorthand syntax: +$(...)+
49 14. Modular build allows many features to be omitted or built as dynamic, loadable modules
50 15. Highly suitable for use in an embedded environment
51 16. Support for UDP, IPv6, Unix-Domain sockets in addition to TCP sockets
57 1. Add `file mtimeus` for high resolution file timestamps
58 2. `aio` now supports datagram Unix-Domain sockets
59 3. Add support for `aio lock -wait`
60 4. Add `signal block` to prevent delivery of signals
61 5. Add support for `file split`
63 Changes between 0.77 and 0.78
64 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
65 1. Add serial/tty support with `aio tty`
66 2. Add support for 'jimsh -'
67 3. Add hidden '-commands' option to many commands
68 4. Add scriptable autocompletion support in interactive mode with `tcl::autocomplete`
70 6. Add scriptable autocompletion support with `history completion`
71 7. Add support for `tree delete`
72 8. Add support for `defer` and '$jim::defer'
73 9. Renamed `os.wait` to `wait`, now more Tcl-compatible and compatible with `exec ... &`
74 10. `pipe` is now a synonym for `socket pipe`
75 11. Closing a pipe open with `open |...` now returns Tcl-like status
76 12. It is now possible to used `exec` redirection with a pipe opened with `open |...`
77 13. Interactive line editing now supports multiline mode if $::history::multiline is set
79 Changes between 0.76 and 0.77
80 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
81 1. Add support for `aio sync`
82 2. Add SSL and TLS support in aio
84 4. Added support for boolean constants in `expr`
85 5. `string is` now supports 'boolean' class
86 6. Add support for `aio lock` and `aio unlock`
87 7. Add new `interp` command
89 Changes between 0.75 and 0.76
90 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
91 1. `glob` now supports the +-tails+ option
92 2. Add support for `string cat`
93 3. Allow `info source` to add source info
95 Changes between 0.74 and 0.75
96 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
97 1. `binary`, `pack` and `unpack` now support floating point
98 2. `file copy` +-force+ handles source and target as the same file
99 3. `format` now supports +%b+ for binary conversion
100 4. `lsort` now supports +-unique+ and +-real+
101 5. Add support for half-close with `aio close` +?r|w?+
102 6. Add `socket pair` for a bidirectional pipe
103 7. Add '--random-hash' to randomise hash tables for greater security
104 8. `dict` now supports 'for', 'values', 'incr', 'append', 'lappend', 'update', 'info' and 'replace'
105 9. `file stat` no longer requires the variable name
106 10. Add support for `file link`
108 Changes between 0.73 and 0.74
109 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
110 1. Numbers with leading zeros are treated as decimal, not octal
112 3. Add LFS (64 bit) support for `aio seek`, `aio tell`, `aio copyto`, `file copy`
113 4. `string compare` and `string equal` now support '-length'
114 5. `glob` now supports '-directory'
116 Changes between 0.72 and 0.73
117 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
118 1. Built-in regexp now support non-capturing parentheses: (?:...)
119 2. Add `string replace`
120 3. Add `string totitle`
121 4. Add `info statics`
122 5. Add +build-jim-ext+ for easy separate building of loadable modules (extensions)
123 6. `local` now works with any command, not just procs
124 7. Add `info alias` to access the target of an alias
125 8. UTF-8 encoding past the basic multilingual plane (BMP) is supported
128 11. Most extensions are now enabled by default
129 12. Add support for namespaces and the `namespace` command
132 Changes between 0.71 and 0.72
133 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
134 1. procs now allow 'args' and optional parameters in any position
135 2. Add Tcl-compatible expr functions, `rand()`, `srand()` and `pow()`
136 3. Add support for the '-force' option to `file delete`
137 4. Better diagnostics when `source` fails to load a script with a missing quote or bracket
138 5. New +tcl_platform(pathSeparator)+
139 6. Add support settings the modification time with `file mtime`
140 7. `exec` is now fully supported on win32 (mingw32)
141 8. `file join`, `pwd`, `glob` etc. now work for mingw32
142 9. Line editing is now supported for the win32 console (mingw32)
143 10. Add `aio listen` command
145 Changes between 0.70 and 0.71
146 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
147 1. Allow 'args' to be renamed in procs
148 2. Add +$(...)+ shorthand syntax for expressions
149 3. Add automatic reference variables in procs with +&var+ syntax
150 4. Support +jimsh --version+
151 5. Additional variables in +tcl_platform()+
152 6. `local` procs now push existing commands and `upcall` can call them
153 7. Add `loop` command (TclX compatible)
154 8. Add `aio buffering` command
155 9. `info complete` can now return the missing character
156 10. `binary format` and `binary scan` are now (optionally) supported
157 11. Add `string byterange`
158 12. Built-in regexp now support non-greedy repetition (*?, +?, ??)
162 Tcl stands for 'tool command language' and is pronounced
163 'http://www.oxforddictionaries.com/definition/american_english/tickle[tickle]'.
164 It is actually two things: a language and a library.
166 First, Tcl is a simple textual language, intended primarily for
167 issuing commands to interactive programs such as text editors,
168 debuggers, illustrators, and shells. It has a simple syntax and is also
169 programmable, so Tcl users can write command procedures to provide more
170 powerful commands than those in the built-in set.
172 Second, Tcl is a library package that can be embedded in application
173 programs. The Tcl library consists of a parser for the Tcl language,
174 routines to implement the Tcl built-in commands, and procedures that
175 allow each application to extend Tcl with additional commands specific
176 to that application. The application program generates Tcl commands and
177 passes them to the Tcl parser for execution. Commands may be generated
178 by reading characters from an input source, or by associating command
179 strings with elements of the application's user interface, such as menu
180 entries, buttons, or keystrokes.
182 When the Tcl library receives commands it parses them into component
183 fields and executes built-in commands directly. For commands implemented
184 by the application, Tcl calls back to the application to execute the
185 commands. In many cases commands will invoke recursive invocations of the
186 Tcl interpreter by passing in additional strings to execute (procedures,
187 looping commands, and conditional commands all work in this way).
189 An application program gains three advantages by using Tcl for its command
190 language. First, Tcl provides a standard syntax: once users know Tcl,
191 they will be able to issue commands easily to any Tcl-based application.
192 Second, Tcl provides programmability. All a Tcl application needs
193 to do is to implement a few application-specific low-level commands.
194 Tcl provides many utility commands plus a general programming interface
195 for building up complex command procedures. By using Tcl, applications
196 need not re-implement these features.
198 Third, Tcl can be used as a common language for communicating between
199 applications. Inter-application communication is not built into the
200 Tcl core described here, but various add-on libraries, such as the Tk
201 toolkit, allow applications to issue commands to each other. This makes
202 it possible for applications to work together in much more powerful ways
203 than was previously possible.
205 Fourth, Jim Tcl includes a command processor, +jimsh+, which can be
206 used to run standalone Tcl scripts, or to run Tcl commands interactively.
208 This manual page focuses primarily on the Tcl language. It describes
209 the language syntax and the built-in commands that will be available
210 in any application based on Tcl. The individual library procedures are
211 described in more detail in separate manual pages, one per procedure.
213 JIMSH COMMAND INTERPRETER
214 -------------------------
215 A simple, but powerful command processor, +jimsh+, is part of Jim Tcl.
216 It may be invoked in interactive mode as:
220 or to process the Tcl script in a file with:
224 or to process the Tcl script from standard input:
228 It may also be invoked to execute an immediate script with:
234 Interactive mode reads Tcl commands from standard input, evaluates
235 those commands and prints the results.
238 Welcome to Jim version 0.73, Copyright (c) 2005-8 Salvatore Sanfilippo
241 . lsort [info commands p*]
242 package parray pid popen proc puts pwd
243 . foreach i {a b c} {
250 invalid command name "bad"
254 If +jimsh+ is configured with line editing (it is by default) and a VT-100-compatible
255 terminal is detected, Emacs-style line editing commands are available, including:
256 arrow keys, +\^W+ to erase a word, +\^U+ to erase the line, +^R+ for reverse incremental search
257 in history. Additionally, the +h+ command may be used to display the command history.
259 Command line history is automatically saved and loaded from +~/.jim_history+
261 In interactive mode, +jimsh+ automatically runs the script +~/.jimrc+ at startup
266 The central data structure in Tcl is an interpreter (C type 'Jim_Interp').
267 An interpreter consists of a set of command bindings, a set of variable
268 values, and a few other miscellaneous pieces of state. Each Tcl command
269 is interpreted in the context of a particular interpreter.
271 Some Tcl-based applications will maintain multiple interpreters
272 simultaneously, each associated with a different widget or portion of
273 the application. Interpreters are relatively lightweight structures.
274 They can be created and deleted quickly, so application programmers should
275 feel free to use multiple interpreters if that simplifies the application.
279 Tcl supports only one type of data: strings. All commands, all arguments
280 to commands, all command results, and all variable values are strings.
282 Where commands require numeric arguments or return numeric results,
283 the arguments and results are passed as strings. Many commands expect
284 their string arguments to have certain formats, but this interpretation
285 is up to the individual commands. For example, arguments often contain
286 Tcl command strings, which may get executed as part of the commands.
287 The easiest way to understand the Tcl interpreter is to remember that
288 everything is just an operation on a string. In many cases Tcl constructs
289 will look similar to more structured constructs from other languages.
290 However, the Tcl constructs are not structured at all; they are just
291 strings of characters, and this gives them a different behaviour than
292 the structures they may look like.
294 Although the exact interpretation of a Tcl string depends on who is doing
295 the interpretation, there are three common forms that strings take:
296 commands, expressions, and lists. The major sections below discuss
297 these three forms in more detail.
301 The Tcl language has syntactic similarities to both the Unix shells
302 and Lisp. However, the interpretation of commands is different
303 in Tcl than in either of those other two systems.
304 A Tcl command string consists of one or more commands separated
305 by newline characters or semi-colons.
306 Each command consists of a collection of fields separated by
307 white space (spaces or tabs).
308 The first field must be the name of a command, and the
309 additional fields, if any, are arguments that will be passed to
310 that command. For example, the command:
314 has three fields: the first, `set`, is the name of a Tcl command, and
315 the last two, 'a' and '22', will be passed as arguments to
316 the `set` command. The command name may refer either to a built-in
317 Tcl command, an application-specific command bound in with the library
318 procedure 'Jim_CreateCommand', or a command procedure defined with the
319 `proc` built-in command.
321 Arguments are passed literally as text strings. Individual commands may
322 interpret those strings in any fashion they wish. The `set` command,
323 for example, will treat its first argument as the name of a variable
324 and its second argument as a string value to assign to that variable.
325 For other commands arguments may be interpreted as integers, lists,
326 file names, or Tcl commands.
328 Command names should normally be typed completely (e.g. no abbreviations).
329 However, if the Tcl interpreter cannot locate a command it invokes a
330 special command named `unknown` which attempts to find or create the
333 For example, at many sites `unknown` will search through library
334 directories for the desired command and create it as a Tcl procedure if
335 it is found. The `unknown` command often provides automatic completion
336 of abbreviated commands, but usually only for commands that were typed
339 It's probably a bad idea to use abbreviations in command scripts and
340 other forms that will be re-used over time: changes to the command set
341 may cause abbreviations to become ambiguous, resulting in scripts that
346 If the first non-blank character in a command is +\#+, then everything
347 from the +#+ up through the next newline character is treated as
348 a comment and ignored. When comments are embedded inside nested
349 commands (e.g. fields enclosed in braces) they must have properly-matched
350 braces (this is necessary because when Tcl parses the top-level command
351 it doesn't yet know that the nested field will be used as a command so
352 it cannot process the nested comment character as a comment).
354 GROUPING ARGUMENTS WITH DOUBLE-QUOTES
355 -------------------------------------
356 Normally each argument field ends at the next white space, but
357 double-quotes may be used to create arguments with embedded space.
359 If an argument field begins with a double-quote, then the argument isn't
360 terminated by white space (including newlines) or a semi-colon (see below
361 for information on semi-colons); instead it ends at the next double-quote
362 character. The double-quotes are not included in the resulting argument.
363 For example, the command
365 set a "This is a single argument"
367 will pass two arguments to `set`: 'a' and 'This is a single argument'.
369 Within double-quotes, command substitutions, variable substitutions,
370 and backslash substitutions still occur, as described below. If the
371 first character of a command field is not a quote, then quotes receive
372 no special interpretation in the parsing of that field.
374 GROUPING ARGUMENTS WITH BRACES
375 ------------------------------
376 Curly braces may also be used for grouping arguments. They are similar
377 to quotes except for two differences. First, they nest; this makes them
378 easier to use for complicated arguments like nested Tcl command strings.
379 Second, the substitutions described below for commands, variables, and
380 backslashes do *not* occur in arguments enclosed in braces, so braces
381 can be used to prevent substitutions where they are undesirable.
383 If an argument field begins with a left brace, then the argument ends
384 at the matching right brace. Tcl will strip off the outermost layer
385 of braces and pass the information between the braces to the command
386 without any further modification. For example, in the command
388 set a {xyz a {b c d}}
390 the `set` command will receive two arguments: 'a'
393 When braces or quotes are in effect, the matching brace or quote need
394 not be on the same line as the starting quote or brace; in this case
395 the newline will be included in the argument field along with any other
396 characters up to the matching brace or quote. For example, the `eval`
397 command takes one argument, which is a command string; `eval` invokes
398 the Tcl interpreter to execute the command string. The command
405 will assign the value '22' to 'a' and '33' to 'b'.
407 If the first character of a command field is not a left
408 brace, then neither left nor right
409 braces in the field will be treated specially (except as part of
410 variable substitution; see below).
412 COMMAND SUBSTITUTION WITH BRACKETS
413 ----------------------------------
414 If an open bracket occurs in a field of a command, then command
415 substitution occurs (except for fields enclosed in braces). All of the
416 text up to the matching close bracket is treated as a Tcl command and
417 executed immediately. Then the result of that command is substituted
418 for the bracketed text. For example, consider the command
422 When the `set` command has only a single argument, it is the name of a
423 variable and `set` returns the contents of that variable. In this case,
424 if variable 'b' has the value 'foo', then the command above is equivalent
429 Brackets can be used in more complex ways. For example, if the variable
430 'b' has the value 'foo' and the variable 'c' has the value 'gorp',
433 set a xyz[set b].[set c]
435 is equivalent to the command
440 A bracketed command may contain multiple commands separated by newlines
441 or semi-colons in the usual fashion. In this case the value of the last
442 command is used for substitution. For example, the command
447 is equivalent to the command
452 If a field is enclosed in braces then the brackets and the characters
453 between them are not interpreted specially; they are passed through to
454 the argument verbatim.
456 VARIABLE SUBSTITUTION WITH $
457 ----------------------------
458 The dollar sign (+$+) may be used as a special shorthand form for
459 substituting variable values. If +$+ appears in an argument that isn't
460 enclosed in braces then variable substitution will occur. The characters
461 after the +$+, up to the first character that isn't a number, letter,
462 or underscore, are taken as a variable name and the string value of that
463 variable is substituted for the name.
465 For example, if variable 'foo' has the value 'test', then the command
469 is equivalent to the command
473 There are two special forms for variable substitution. If the next
474 character after the name of the variable is an open parenthesis, then
475 the variable is assumed to be an array name, and all of the characters
476 between the open parenthesis and the next close parenthesis are taken as
477 an index into the array. Command substitutions and variable substitutions
478 are performed on the information between the parentheses before it is
481 For example, if the variable 'x' is an array with one element named
482 'first' and value '87' and another element named '14' and value 'more',
485 set a xyz$x(first)zyx
487 is equivalent to the command
491 If the variable 'index' has the value '14', then the command
493 set a xyz$x($index)zyx
495 is equivalent to the command
499 For more information on arrays, see VARIABLES AND ARRAYS below.
501 The second special form for variables occurs when the dollar sign is
502 followed by an open curly brace. In this case the variable name consists
503 of all the characters up to the next curly brace.
505 Array references are not possible in this form: the name between braces
506 is assumed to refer to a scalar variable. For example, if variable
507 'foo' has the value 'test', then the command
511 is equivalent to the command
516 Variable substitution does not occur in arguments that are enclosed in
517 braces: the dollar sign and variable name are passed through to the
520 The dollar sign abbreviation is simply a shorthand form. +$a+ is
521 completely equivalent to +[set a]+; it is provided as a convenience
524 SEPARATING COMMANDS WITH SEMI-COLONS
525 ------------------------------------
526 Normally, each command occupies one line (the command is terminated by a
527 newline character). However, semi-colon (+;+) is treated as a command
528 separator character; multiple commands may be placed on one line by
529 separating them with a semi-colon. Semi-colons are not treated as
530 command separators if they appear within curly braces or double-quotes.
532 BACKSLASH SUBSTITUTION
533 ----------------------
534 Backslashes may be used to insert non-printing characters into command
535 fields and also to insert special characters like braces and brackets
536 into fields without them being interpreted specially as described above.
538 The backslash sequences understood by the Tcl interpreter are
539 listed below. In each case, the backslash
540 sequence is replaced by the given character:
541 [[BackslashSequences]]
552 Carriage-return (0xd).
575 +{backslash}<space>+::
576 Space ( ): doesn't terminate argument.
579 Semi-colon: doesn't terminate command.
584 +{backslash}<newline>+::
585 Nothing: this joins two lines together
586 into a single line. This backslash feature is unique in that
587 it will be applied even when the sequence occurs within braces.
589 +{backslash}{backslash}+::
590 Backslash ('{backslash}').
593 The digits +'ddd'+ (one, two, or three of them) give the octal value of
594 the character. Note that Jim supports null characters in strings.
597 +{backslash}u\{nnn\}+::
598 +{backslash}Unnnnnnnn+::
599 The UTF-8 encoding of the unicode codepoint represented by the hex digits, +'nnnn'+, is inserted.
600 The 'u' form allows for one to four hex digits.
601 The 'U' form allows for one to eight hex digits.
602 The 'u\{nnn\}' form allows for one to eight hex digits, but makes it easier to insert
603 characters UTF-8 characters which are followed by a hex digit.
605 For example, in the command
609 the second argument to `set` will be +{x[ yza+.
611 If a backslash is followed by something other than one of the options
612 described above, then the backslash is transmitted to the argument
613 field without any special processing, and the Tcl scanner continues
614 normal processing with the next character. For example, in the
619 The first argument to `set` will be +{backslash}*a+ and the second
620 argument will be +{backslash}{foo+.
622 If an argument is enclosed in braces, then backslash sequences inside
623 the argument are parsed but no substitution occurs (except for
624 backslash-newline): the backslash
625 sequence is passed through to the argument as is, without making
626 any special interpretation of the characters in the backslash sequence.
627 In particular, backslashed braces are not counted in locating the
628 matching right brace that terminates the argument.
634 the second argument to `set` will be +{backslash}{abc+.
636 This backslash mechanism is not sufficient to generate absolutely
637 any argument structure; it only covers the
638 most common cases. To produce particularly complicated arguments
639 it is probably easiest to use the `format` command along with
640 command substitution.
642 STRING AND LIST INDEX SPECIFICATIONS
643 ------------------------------------
645 Many string and list commands take one or more 'index' parameters which
646 specify a position in the string relative to the start or end of the string/list.
648 The index may be one of the following forms:
651 A simple integer, where '0' refers to the first element of the string
654 +integer+integer+ or::
656 The sum or difference of the two integers. e.g. +2+3+ refers to the 5th element.
657 This is useful when used with (e.g.) +$i+1+ rather than the more verbose
661 The last element of the string or list.
664 The 'nth-from-last' element of the string or list.
668 1. A command is just a string.
669 2. Within a string commands are separated by newlines or semi-colons
670 (unless the newline or semi-colon is within braces or brackets
672 3. A command consists of fields. The first field is the name of the command.
673 The other fields are strings that are passed to that command as arguments.
674 4. Fields are normally separated by white space.
675 5. Double-quotes allow white space and semi-colons to appear within
677 Command substitution, variable substitution, and backslash substitution
678 still occur inside quotes.
679 6. Braces defer interpretation of special characters.
680 If a field begins with a left brace, then it consists of everything
681 between the left brace and the matching right brace. The
682 braces themselves are not included in the argument.
683 No further processing is done on the information between the braces
684 except that backslash-newline sequences are eliminated.
685 7. If a field doesn't begin with a brace then backslash,
686 variable, and command substitution are done on the field. Only a
687 single level of processing is done: the results of one substitution
688 are not scanned again for further substitutions or any other
689 special treatment. Substitution can
690 occur on any field of a command, including the command name
691 as well as the arguments.
692 8. If the first non-blank character of a command is a +\#+, everything
693 from the +#+ up through the next newline is treated as a comment
698 The second major interpretation applied to strings in Tcl is
699 as expressions. Several commands, such as `expr`, `for`,
700 and `if`, treat one or more of their arguments as expressions
701 and call the Tcl expression processors ('Jim_ExprLong',
702 'Jim_ExprBoolean', etc.) to evaluate them.
704 The operators permitted in Tcl expressions are a subset of
705 the operators permitted in C expressions, and they have the
706 same meaning and precedence as the corresponding C operators.
707 Expressions almost always yield numeric results
708 (integer or floating-point values).
709 For example, the expression
715 Tcl expressions differ from C expressions in the way that
716 operands are specified, and in that Tcl expressions support
717 non-numeric operands and string comparisons.
719 A Tcl expression consists of a combination of operands, operators,
722 White space may be used between the operands and operators and
723 parentheses; it is ignored by the expression processor.
724 Where possible, operands are interpreted as integer values.
726 Integer values may be specified in decimal (the normal case) or in
727 hexadecimal (if the first two characters of the operand are '0x').
728 Note that Jim Tcl does *not* treat numbers with leading zeros as octal.
730 If an operand does not have one of the integer formats given
731 above, then it is treated as a floating-point number if that is
732 possible. Floating-point numbers may be specified in any of the
733 ways accepted by an ANSI-compliant C compiler (except that the
734 'f', 'F', 'l', and 'L' suffixes will not be permitted in
735 most installations). For example, all of the
736 following are valid floating-point numbers: 2.1, 3., 6e4, 7.91e+16.
738 If no numeric interpretation is possible, then an operand is left
739 as a string (and only a limited set of operators may be applied to
742 String constants representing boolean constants
743 (+'0'+, +'1'+, +'false'+, +'off'+, +'no'+, +'true'+, +'on'+, +'yes'+)
744 are also recognized and can be used in logical operations.
746 1. Operands may be specified in any of the following ways:
748 2. As a numeric value, either integer or floating-point.
750 3. As one of valid boolean constants
752 4. As a Tcl variable, using standard '$' notation.
753 The variable's value will be used as the operand.
755 5. As a string enclosed in double-quotes.
756 The expression parser will perform backslash, variable, and
757 command substitutions on the information between the quotes,
758 and use the resulting value as the operand
760 6. As a string enclosed in braces.
761 The characters between the open brace and matching close brace
762 will be used as the operand without any substitutions.
764 7. As a Tcl command enclosed in brackets.
765 The command will be executed and its result will be used as
768 Where substitutions occur above (e.g. inside quoted strings), they
769 are performed by the expression processor.
770 However, an additional layer of substitution may already have
771 been performed by the command parser before the expression
772 processor was called.
774 As discussed below, it is usually best to enclose expressions
775 in braces to prevent the command parser from performing substitutions
778 For some examples of simple expressions, suppose the variable 'a' has
779 the value 3 and the variable 'b' has the value 6. Then the expression
780 on the left side of each of the lines below will evaluate to the value
781 on the right side of the line:
786 {word one} < "word $a" 0
788 The valid operators are listed below, grouped in decreasing order
790 [[OperatorPrecedence]]
791 +int() double() round() abs(), rand(), srand()+::
792 Unary functions (except rand() which takes no arguments)
793 * +'int()'+ converts the numeric argument to an integer by truncating down.
794 * +'double()'+ converts the numeric argument to floating point.
795 * +'round()'+ converts the numeric argument to the closest integer value.
796 * +'abs()'+ takes the absolute value of the numeric argument.
797 * +'rand()'+ returns a pseudo-random floating-point value in the range (0,1).
798 * +'srand()'+ takes an integer argument to (re)seed the random number generator. Returns the first random number from that seed.
800 +sin() cos() tan() asin() acos() atan() sinh() cosh() tanh() ceil() floor() exp() log() log10() sqrt()+::
801 Unary math functions.
802 If Jim is compiled with math support, these functions are available.
805 Unary minus, unary plus, bit-wise NOT, logical NOT. None of these operands
806 may be applied to string operands, and bit-wise NOT may be
807 applied only to integers.
810 Power. e.g. 'x^y^'. If Jim is compiled with math support, supports doubles and
811 integers. Otherwise supports integers only. (Note that the math-function form
812 has the same highest precedence)
815 Multiply, divide, remainder. None of these operands may be
816 applied to string operands, and remainder may be applied only
820 Add and subtract. Valid for any numeric operands.
823 Left and right shift, left and right rotate. Valid for integer operands only.
826 Boolean less, greater, less than or equal, and greater than or equal.
827 Each operator produces 1 if the condition is true, 0 otherwise.
828 These operators may be applied to strings as well as numeric operands,
829 in which case string comparison is used.
832 Boolean equal and not equal. Each operator produces a zero/one result.
833 Valid for all operand types. *Note* that values will be converted to integers
834 if possible, then floating point types, and finally strings will be compared.
835 It is recommended that 'eq' and 'ne' should be used for string comparison.
838 String equal and not equal. Uses the string value directly without
839 attempting to convert to a number first.
842 String in list and not in list. For 'in', result is 1 if the left operand (as a string)
843 is contained in the right operand (as a list), or 0 otherwise. The result for
844 +{$a ni $list}+ is equivalent to +{!($a in $list)}+.
847 Bit-wise AND. Valid for integer operands only.
850 Bit-wise OR. Valid for integer operands only.
853 Bit-wise exclusive OR. Valid for integer operands only.
856 Logical AND. Produces a 1 result if both operands are non-zero, 0 otherwise.
857 Valid for numeric operands only (integers or floating-point).
860 Logical OR. Produces a 0 result if both operands are zero, 1 otherwise.
861 Valid for numeric operands only (integers or floating-point).
864 If-then-else, as in C. If +'x'+
865 evaluates to non-zero, then the result is the value of +'y'+.
866 Otherwise the result is the value of +'z'+.
867 The +'x'+ operand must have a numeric value, while +'y'+ and +'z'+ can
870 See the C manual for more details on the results
871 produced by each operator.
872 All of the binary operators group left-to-right within the same
873 precedence level. For example, the expression
879 The +&&+, +||+, and +?:+ operators have 'lazy evaluation', just as
880 in C, which means that operands are not evaluated if they are not
881 needed to determine the outcome. For example, in
885 only one of +[a]+ or +[b]+ will actually be evaluated,
886 depending on the value of +$v+.
888 All internal computations involving integers are done with the C
889 type 'long long' if available, or 'long' otherwise, and all internal
890 computations involving floating-point are done with the C type
893 When converting a string to floating-point, exponent overflow is
894 detected and results in a Tcl error.
895 For conversion to integer from string, detection of overflow depends
896 on the behaviour of some routines in the local C library, so it should
897 be regarded as unreliable.
898 In any case, overflow and underflow are generally not detected
899 reliably for intermediate results.
901 Conversion among internal representations for integer, floating-point,
902 string operands is done automatically as needed.
903 For arithmetic computations, integers are used until some
904 floating-point number is introduced, after which floating-point is used.
909 yields the result 1, while
912 5 / ( [string length "abcd"] + 0.0 )
914 both yield the result 1.25.
916 String values may be used as operands of the comparison operators,
917 although the expression evaluator tries to do comparisons as integer
918 or floating-point when it can.
919 If one of the operands of a comparison is a string and the other
920 has a numeric value, the numeric operand is converted back to
921 a string using the C 'sprintf' format specifier
922 '%d' for integers and '%g' for floating-point values.
923 For example, the expressions
928 both evaluate to 1. The first comparison is done using integer
929 comparison, and the second is done using string comparison after
930 the second operand is converted to the string '18'.
932 In general it is safest to enclose an expression in braces when
933 entering it in a command: otherwise, if the expression contains
934 any white space then the Tcl interpreter will split it
935 among several arguments. For example, the command
939 results in three arguments being passed to `expr`: +$a+,
940 \+, and +$b+. In addition, if the expression isn't in braces
941 then the Tcl interpreter will perform variable and command substitution
942 immediately (it will happen in the command parser rather than in
943 the expression parser). In many cases the expression is being
944 passed to a command that will evaluate the expression later (or
945 even many times if, for example, the expression is to be used to
946 decide when to exit a loop). Usually the desired goal is to re-do
947 the variable or command substitutions each time the expression is
948 evaluated, rather than once and for all at the beginning. For example,
951 for {set i 1} $i<=10 {incr i} {...} ** WRONG **
953 is probably intended to iterate over all values of +i+ from 1 to 10.
954 After each iteration of the body of the loop, `for` will pass
955 its second argument to the expression evaluator to see whether or not
956 to continue processing. Unfortunately, in this case the value of +i+
957 in the second argument will be substituted once and for all when the
958 `for` command is parsed. If +i+ was 0 before the `for`
959 command was invoked then the second argument of `for` will be +0\<=10+
960 which will always evaluate to 1, even though +i+ eventually
961 becomes greater than 10. In the above case the loop will never
962 terminate. Instead, the expression should be placed in braces:
964 for {set i 1} {$i<=10} {incr i} {...} ** RIGHT **
966 This causes the substitution of 'i'
967 to be delayed; it will be re-done each time the expression is
968 evaluated, which is the desired result.
972 The third major way that strings are interpreted in Tcl is as lists.
973 A list is just a string with a list-like structure
974 consisting of fields separated by white space. For example, the
979 is a list with four elements or fields.
980 Lists have the same basic structure as command strings, except
981 that a newline character in a list is treated as a field separator
982 just like space or tab. Conventions for braces and quotes
983 and backslashes are the same for lists as for commands. For example,
988 is a list with three elements: +a+, +b c+, and +d e {f g h}+.
990 Whenever an element is extracted from a list, the same rules about
991 braces and quotes and backslashes are applied as for commands. Thus in
992 the example above when the third element is extracted from the list,
997 (when the field was extracted, all that happened was to strip off
998 the outermost layer of braces). Command substitution and
999 variable substitution are never
1000 made on a list (at least, not by the list-processing commands; the
1001 list can always be passed to the Tcl interpreter for evaluation).
1003 The Tcl commands `concat`, `foreach`, `lappend`, `lindex`, `linsert`,
1004 `list`, `llength`, `lrange`, `lreplace`, `lsearch`, and `lsort` allow
1005 you to build lists, extract elements from them, search them, and perform
1006 other list-related functions.
1008 Advanced list commands include `lrepeat`, `lreverse`, `lmap`, `lassign`, `lset`.
1013 A new addition to Tcl 8.5 is the ability to expand a list into separate
1014 arguments. Support for this feature is also available in Jim.
1016 Consider the following attempt to exec a list:
1021 This will attempt to exec a command named "ls -l", which will clearly not
1022 work. Typically eval and concat are required to solve this problem, however
1023 it can be solved much more easily with +\{*\}+.
1027 This will expand the following argument into individual elements and then evaluate
1028 the resulting command.
1030 Note that the official Tcl syntax is +\{*\}+, however +\{expand\}+ is retained
1031 for backward compatibility with experimental versions of this feature.
1035 Tcl provides two commands that support string matching using regular
1036 expressions, `regexp` and `regsub`, as well as `switch -regexp` and
1039 Regular expressions may be implemented one of two ways. Either using the system's C library
1040 POSIX regular expression support, or using the built-in regular expression engine.
1041 The differences between these are described below.
1043 *NOTE* Tcl 7.x and 8.x use perl-style Advanced Regular Expressions (+ARE+).
1045 POSIX Regular Expressions
1046 ~~~~~~~~~~~~~~~~~~~~~~~~~
1047 If the system supports POSIX regular expressions, and UTF-8 support is not enabled,
1048 this support will be used by default. The type of regular expressions supported are
1049 Extended Regular Expressions (+ERE+) rather than Basic Regular Expressions (+BRE+).
1050 See REG_EXTENDED in the documentation.
1052 Using the system-supported POSIX regular expressions will typically
1053 make for the smallest code size, but some features such as UTF-8
1054 and +{backslash}w+, +{backslash}d+, +{backslash}s+ are not supported, and null characters
1055 in strings are not supported.
1057 See regex(3) and regex(7) for full details.
1059 Jim built-in Regular Expressions
1060 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1061 The Jim built-in regular expression engine may be selected with +./configure --with-jim-regexp+
1062 or it will be selected automatically if UTF-8 support is enabled.
1064 This engine supports UTF-8 as well as some +ARE+ features. The differences with both Tcl 7.x/8.x
1065 and POSIX are highlighted below.
1067 1. UTF-8 strings and patterns are both supported
1068 2. All Tcl character classes are supported (e.g. +[:alnum:]+, +[:digit:]+, +[:space:]+), but...
1069 3. Character classes apply to ASCII characters only
1070 4. Supported shorthand character classes: +{backslash}w+ = +[:alnum:]+, +{backslash}W+ = +^[:alnum:]+, +{backslash}d+ = +[:digit:],+ +{backslash}D+ = +^[:digit:],+ +{backslash}s+ = +[:space:]+, + +{backslash}S+ = +^[:space:]+
1071 5. Supported constraint escapes: +{backslash}m+ = +{backslash}<+ = start of word, +{backslash}M+ = +{backslash}>+ = end of word
1072 6. Backslash escapes may be used within regular expressions, such as +{backslash}n+ = newline, +{backslash}uNNNN+ = unicode
1073 7. Partially supported constraint escapes: +{backslash}A+ = start of string, +{backslash}Z+ = end of string
1074 8. Support for the +?+ non-greedy quantifier. e.g. +*?+
1075 9. Support for non-capturing parentheses +(?:...)+
1076 10. Jim Tcl considers that both patterns and strings end at a null character (+\x00+)
1080 Each command produces two results: a code and a string. The
1081 code indicates whether the command completed successfully or not,
1082 and the string gives additional information. The valid codes are
1083 defined in jim.h, and are:
1086 This is the normal return code, and indicates that the command completed
1087 successfully. The string gives the command's return value.
1090 Indicates that an error occurred; the string gives a message describing
1094 Indicates that the `return` command has been invoked, and that the
1095 current procedure (or top-level command or `source` command)
1096 should return immediately. The
1097 string gives the return value for the procedure or command.
1100 Indicates that the `break` command has been invoked, so the
1101 innermost loop should abort immediately. The string should always
1105 Indicates that the `continue` command has been invoked, so the
1106 innermost loop should go on to the next iteration. The string
1107 should always be empty.
1110 Indicates that a signal was caught while executing a commands.
1111 The string contains the name of the signal caught.
1112 See the `signal` and `catch` commands.
1115 Indicates that the command called the `exit` command.
1116 The string contains the exit code.
1118 Tcl programmers do not normally need to think about return codes,
1119 since +JIM_OK+ is almost always returned. If anything else is returned
1120 by a command, then the Tcl interpreter immediately stops processing
1121 commands and returns to its caller. If there are several nested
1122 invocations of the Tcl interpreter in progress, then each nested
1123 command will usually return the error to its caller, until eventually
1124 the error is reported to the top-level application code. The
1125 application will then display the error message for the user.
1127 In a few cases, some commands will handle certain `error` conditions
1128 themselves and not return them upwards. For example, the `for`
1129 command checks for the +JIM_BREAK+ code; if it occurs, then `for`
1130 stops executing the body of the loop and returns +JIM_OK+ to its
1131 caller. The `for` command also handles +JIM_CONTINUE+ codes and the
1132 procedure interpreter handles +JIM_RETURN+ codes. The `catch`
1133 command allows Tcl programs to catch errors and handle them without
1134 aborting command interpretation any further.
1136 The `info returncodes` command may be used to programmatically map between
1137 return codes and names.
1141 Tcl allows you to extend the command interface by defining
1142 procedures. A Tcl procedure can be invoked just like any other Tcl
1143 command (it has a name and it receives one or more arguments).
1144 The only difference is that its body isn't a piece of C code linked
1145 into the program; it is a string containing one or more other
1148 The `proc` command is used to create a new Tcl command procedure:
1150 +*proc* 'name arglist ?statics? body'+
1152 The new command is named +'name'+, and it replaces any existing command
1153 there may have been by that name. Whenever the new command is
1154 invoked, the contents of +'body'+ will be executed by the Tcl
1157 +'arglist'+ specifies the formal arguments to the procedure.
1158 It consists of a list, possibly empty, of the following
1159 argument specifiers:
1162 Required Argument - A simple argument name.
1165 Optional Argument - A two-element list consisting of the
1166 argument name, followed by the default value, which will
1167 be used if the corresponding argument is not supplied.
1170 Reference Argument - The caller is expected to pass the name of
1171 an existing variable. An implicit +`upvar` 1 origname name+ is done
1172 to make the variable available in the proc scope.
1175 Variable Argument - The special name +'args'+, which is
1176 assigned all remaining arguments (including none) as a list. The
1177 variable argument may only be specified once. Note that
1178 the syntax +{args newname}+ may be used to retain the special
1179 behaviour of +'args'+ with a different local name. In this case,
1180 the variable is named +'newname'+ rather than +'args'+.
1182 When the command is invoked, a local variable will be created for each of
1183 the formal arguments to the procedure; its value will be the value
1184 of corresponding argument in the invoking command or the argument's
1187 Arguments with default values need not be specified in a procedure
1188 invocation. However, there must be enough actual arguments for all
1189 required arguments, and there must not be any extra actual arguments
1190 (unless the Variable Argument is specified).
1192 Actual arguments are assigned to formal arguments as in left-to-right
1193 order with the following precedence.
1195 1. Required Arguments (including Reference Arguments)
1196 2. Optional Arguments
1197 3. Variable Argument
1199 The following example illustrates precedence. Assume a procedure declaration:
1201 proc p {{a A} args b {c C} d} {...}
1203 This procedure requires at least two arguments, but can accept an unlimited number.
1204 The following table shows how various numbers of arguments are assigned.
1205 Values marked as +-+ are assigned the default value.
1207 [width="40%",frame="topbot",options="header"]
1209 |Number of arguments|a|args|b|c|d
1217 When +'body'+ is being executed, variable names normally refer to local
1218 variables, which are created automatically when referenced and deleted
1219 when the procedure returns. One local variable is automatically created
1220 for each of the procedure's arguments. Global variables can be
1221 accessed by invoking the `global` command or via the +::+ prefix.
1225 In addition to procedure arguments, Jim procedures may declare static variables.
1226 These variables scoped to the procedure and initialised at procedure definition.
1227 Either from the static variable definition, or from the enclosing scope.
1229 Consider the following example:
1232 jim> proc a {} {a {b 2}} {
1244 The static variable +'a'+ has no initialiser, so it is initialised from
1245 the enclosing scope with the value 1. (Note that it is an error if there
1246 is no variable with the same name in the enclosing scope). However +'b'+
1247 has an initialiser, so it is initialised to 2.
1249 Unlike a local variable, the value of a static variable is retained across
1250 invocations of the procedure.
1252 See the `proc` command for information on how to define procedures
1253 and what happens when they are invoked. See also NAMESPACES.
1255 VARIABLES - SCALARS AND ARRAYS
1256 ------------------------------
1257 Tcl allows the definition of variables and the use of their values
1258 either through '$'-style variable substitution, the `set`
1259 command, or a few other mechanisms.
1261 Variables need not be declared: a new variable will automatically
1262 be created each time a new variable name is used.
1264 Tcl supports two types of variables: scalars and arrays.
1265 A scalar variable has a single value, whereas an array variable
1266 can have any number of elements, each with a name (called
1267 its 'index') and a value.
1269 Array indexes may be arbitrary strings; they need not be numeric.
1270 Parentheses are used refer to array elements in Tcl commands.
1271 For example, the command
1275 will modify the element of 'x' whose index is 'first'
1276 so that its new value is '44'.
1278 Two-dimensional arrays can be simulated in Tcl by using indexes
1279 that contain multiple concatenated values.
1280 For example, the commands
1285 set the elements of 'a' whose indexes are '2,3' and '3,6'.
1287 In general, array elements may be used anywhere in Tcl that scalar
1288 variables may be used.
1290 If an array is defined with a particular name, then there may
1291 not be a scalar variable with the same name.
1293 Similarly, if there is a scalar variable with a particular
1294 name then it is not possible to make array references to the
1297 To convert a scalar variable to an array or vice versa, remove
1298 the existing variable with the `unset` command.
1300 The `array` command provides several features for dealing
1301 with arrays, such as querying the names of all the elements of
1302 the array and converting between an array and a list.
1304 Variables may be either global or local. If a variable
1305 name is used when a procedure isn't being executed, then it
1306 automatically refers to a global variable. Variable names used
1307 within a procedure normally refer to local variables associated with that
1308 invocation of the procedure. Local variables are deleted whenever
1309 a procedure exits. Either `global` command may be used to request
1310 that a name refer to a global variable for the duration of the current
1311 procedure (this is somewhat analogous to 'extern' in C), or the variable
1312 may be explicitly scoped with the +::+ prefix. For example
1328 ARRAYS AS LISTS IN JIM
1329 ----------------------
1330 Unlike Tcl, Jim can automatically convert between a list (with an even
1331 number of elements) and an array value. This is similar to the way Tcl
1332 can convert between a string and a list.
1343 Thus `array set` is equivalent to `set` when the variable does not
1346 The reverse is also true where an array will be converted into
1349 set a(1) one; set a(2) two
1358 Tcl 8.5 introduced the dict command, and Jim Tcl has added a version
1359 of this command. Dictionaries provide efficient access to key-value
1360 pairs, just like arrays, but dictionaries are pure values. This
1361 means that you can pass them to a procedure just as a list or a
1362 string. Tcl dictionaries are therefore much more like Tcl lists,
1363 except that they represent a mapping from keys to values, rather
1364 than an ordered sequence.
1366 You can nest dictionaries, so that the value for a particular key
1367 consists of another dictionary. That way you can elegantly build
1368 complicated data structures, such as hierarchical databases. You
1369 can also combine dictionaries with other Tcl data structures. For
1370 instance, you can build a list of dictionaries that themselves
1373 Dictionaries are values that contain an efficient, order-preserving
1374 mapping from arbitrary keys to arbitrary values. Each key in the
1375 dictionary maps to a single value. They have a textual format that
1376 is exactly that of any list with an even number of elements, with
1377 each mapping in the dictionary being represented as two items in
1378 the list. When a command takes a dictionary and produces a new
1379 dictionary based on it (either returning it or writing it back into
1380 the variable that the starting dictionary was read from) the new
1381 dictionary will have the same order of keys, modulo any deleted
1382 keys and with new keys added on to the end. When a string is
1383 interpreted as a dictionary and it would otherwise have duplicate
1384 keys, only the last value for a particular key is used; the others
1385 are ignored, meaning that, "apple banana" and "apple carrot apple
1386 banana" are equivalent dictionaries (with different string
1389 Note that in Jim, arrays are implemented as dictionaries.
1390 Thus automatic conversion between lists and dictionaries applies
1391 as it does for arrays.
1393 jim> dict set a 1 one
1395 jim> dict set a 2 two
1401 jim> dict set a 3 T three
1402 1 one 2 two 3 {T three}
1404 See the `dict` command for more details.
1408 Tcl added namespaces as a mechanism avoiding name clashes, especially in applications
1409 including a number of 3rd party components. While there is less need for namespaces
1410 in Jim Tcl (which does not strive to support large applications), it is convenient to
1411 provide a subset of the support for namespaces to easy porting code from Tcl.
1413 Jim Tcl currently supports "light-weight" namespaces which should be adequate for most
1414 purposes. This feature is currently experimental. See README.namespaces for more information
1415 and the documentation of the `namespace` command.
1417 GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION
1418 -----------------------------------------------
1419 Unlike Tcl, Jim has some sophisticated support for functional programming.
1420 These are described briefly below.
1422 More information may be found at http://wiki.tcl.tk/13847
1426 A reference can be thought of as holding a value with one level of indirection,
1427 where the value may be garbage collected when unreferenced.
1428 Consider the following example:
1430 jim> set r [ref "One String" test]
1431 <reference.<test___>.00000000000000000000>
1435 The operation `ref` creates a references to the value specified by the
1436 first argument. (The second argument is a "type" used for documentation purposes).
1438 The operation `getref` is the dereferencing operation which retrieves the value
1439 stored in the reference.
1441 jim> setref $r "New String"
1446 The operation `setref` replaces the value stored by the reference. If the old value
1447 is no longer accessible by any reference, it will eventually be automatically be garbage
1452 Normally, all values in Tcl are passed by value. As such values are copied and released
1453 automatically as necessary.
1455 With the introduction of references, it is possible to create values whose lifetime
1456 transcend their scope. To support this, case, the Jim system will periodically identify
1457 and discard objects which are no longer accessible by any reference.
1459 The `collect` command may be used to force garbage collection. Consider a reference created
1462 jim> proc f {ref value} { puts "Finaliser called for $ref,$value" }
1463 jim> set r [ref "One String" test f]
1464 <reference.<test___>.00000000000
1469 Finaliser called for <reference.<test___>.00000000000,One String
1472 Note that once the reference, 'r', was modified so that it no longer
1473 contained a reference to the value, the garbage collector discarded
1474 the value (after calling the finalizer).
1476 The finalizer for a reference may be examined or changed with the `finalize` command
1480 jim> finalize $r newf
1485 Jim provides a garbage collected `lambda` function. This is a procedure
1486 which is able to create an anonymous procedure. Consider:
1488 jim> set f [lambda {a} {{x 0}} { incr x $a }]
1495 This create an anonymous procedure (with the name stored in 'f'), with a static variable
1496 which is incremented by the supplied value and the result returned.
1498 Once the procedure name is no longer accessible, it will automatically be deleted
1499 when the garbage collector runs.
1501 The procedure may also be delete immediately by renaming it "". e.g.
1507 If Jim is built with UTF-8 support enabled (configure --enable-utf),
1508 then most string-related commands become UTF-8 aware. These include,
1509 but are not limited to, `string match`, `split`, `glob`, `scan` and
1512 UTF-8 encoding has many advantages, but one of the complications is that
1513 characters can take a variable number of bytes. Thus the addition of
1514 `string bytelength` which returns the number of bytes in a string,
1515 while `string length` returns the number of characters.
1517 If UTF-8 support is not enabled, all commands treat bytes as characters
1518 and `string bytelength` returns the same value as `string length`.
1520 Note that even if UTF-8 support is not enabled, the +{backslash}uNNNN+ and related syntax
1521 is still available to embed UTF-8 sequences.
1523 Jim Tcl supports all currently defined unicode codepoints. That is 21 bits, up to +'U+1FFFFF'.
1527 Commands such as `string match`, `lsearch -glob`, `array names` and others use string
1528 pattern matching rules. These commands support UTF-8. For example:
1530 string match a\[\ua0-\ubf\]b "a\u00a3b"
1534 +format %c+ allows a unicode codepoint to be be encoded. For example, the following will return
1535 a string with two bytes and one character. The same as +{backslash}ub5+
1539 `format` respects widths as character widths, not byte widths. For example, the following will
1540 return a string with three characters, not three bytes.
1542 format %.3s \ub5\ub6\ub7\ub8
1544 Similarly, +scan ... %c+ allows a UTF-8 to be decoded to a unicode codepoint. The following will set
1545 +'a'+ to 181 (0xb5) and +'b'+ to 65 (0x41).
1547 scan \u00b5A %c%c a b
1549 `scan %s` will also accept a character class, including unicode ranges.
1553 `string is` has *not* been extended to classify UTF-8 characters. Therefore, the following
1554 will return 0, even though the string may be considered to be alphabetic.
1556 string is alpha \ub5Test
1558 This does not affect the string classes 'ascii', 'control', 'digit', 'double', 'integer' or 'xdigit'.
1560 Case Mapping and Conversion
1561 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
1562 Jim provides a simplified unicode case mapping. This means that case conversion
1563 and comparison will not increase or decrease the number of characters in a string.
1564 (Although it may change the number of bytes).
1566 `string toupper` will convert any lowercase letters to their uppercase equivalent.
1567 Any character which is not a letter or has no uppercase equivalent is left unchanged.
1568 Similarly for `string tolower` and `string totitle`.
1570 Commands which perform case insensitive matches, such as `string compare -nocase`
1571 and `lsearch -nocase` fold both strings to uppercase before comparison.
1573 Invalid UTF-8 Sequences
1574 ~~~~~~~~~~~~~~~~~~~~~~~
1575 Some UTF-8 character sequences are invalid, such as those beginning with '0xff',
1576 those which represent character sequences longer than 3 bytes (greater than U+FFFF),
1577 and those which end prematurely, such as a lone '0xc2'.
1579 In these situations, the offending bytes are treated as single characters. For example,
1580 the following returns 2.
1582 string bytelength \xff\xff
1586 If UTF-8 support is enabled, the built-in regular expression engine will be
1587 selected which supports UTF-8 strings and patterns.
1589 See REGULAR EXPRESSIONS
1593 The Tcl library provides the following built-in commands, which will
1594 be available in any application using Tcl. In addition to these
1595 built-in commands, there may be additional commands defined by each
1596 application, plus commands defined as Tcl procedures.
1598 In the command syntax descriptions below, words in +*boldface*+ are
1599 literals that you type verbatim to Tcl.
1601 Words in +'italics'+ are meta-symbols; they serve as names for any of
1602 a range of values that you can type.
1604 Optional arguments or groups of arguments are indicated by enclosing them
1605 in +?question-marks?+.
1607 Ellipses (+\...+) indicate that any number of additional
1608 arguments or groups of arguments may appear, in the same format
1609 as the preceding argument(s).
1620 Delivers the +SIGALRM+ signal to the process after the given
1621 number of seconds. If the platform supports 'ualarm(3)' then
1622 the argument may be a floating point value. Otherwise it must
1625 Note that unless a signal handler for +SIGALRM+ has been installed
1626 (see `signal`), the process will exit on this signal.
1630 +*alias* 'name args\...'+
1632 Creates a single word alias (command) for one or more words. For example,
1633 the following creates an alias for the command `info exists`.
1640 `alias` returns +'name'+, allowing it to be used with `local`.
1642 See also `proc`, `curry`, `lambda`, `local`, `info alias`, `exists -alias`
1646 +*append* 'varName value ?value value ...?'+
1648 Append all of the +'value'+ arguments to the current value
1649 of variable +'varName'+. If +'varName'+ doesn't exist,
1650 it is given a value equal to the concatenation of all the
1651 +'value'+ arguments.
1653 This command provides an efficient way to build up long
1654 variables incrementally.
1655 For example, "`append a $b`" is much more efficient than
1656 "`set a $a$b`" if +$a+ is long.
1660 +*apply* 'lambdaExpr ?arg1 arg2 \...?'+
1662 The command `apply` provides for anonymous procedure calls,
1663 similar to `lambda`, but without command name being created, even temporarily.
1665 The function +'lambdaExpr'+ is a two element list +{args body}+
1666 or a three element list +{args body namespace}+. The first element
1667 args specifies the formal arguments, in the same form as the `proc` and `lambda` commands.
1671 +*array* 'option arrayName ?arg\...?'+
1673 This command performs one of several operations on the
1674 variable given by +'arrayName'+.
1676 Note that in general, if the named array does not exist, the +'array'+ command behaves
1677 as though the array exists but is empty.
1679 The +'option'+ argument determines what action is carried out by the
1680 command. The legal +'options'+ (which may be abbreviated) are:
1682 +*array exists* 'arrayName'+::
1683 Returns 1 if arrayName is an array variable, 0 if there is
1684 no variable by that name.
1686 +*array get* 'arrayName ?pattern?'+::
1687 Returns a list containing pairs of elements. The first
1688 element in each pair is the name of an element in arrayName
1689 and the second element of each pair is the value of the
1690 array element. The order of the pairs is undefined. If
1691 pattern is not specified, then all of the elements of the
1692 array are included in the result. If pattern is specified,
1693 then only those elements whose names match pattern (using
1694 the matching rules of string match) are included. If arrayName
1695 isn't the name of an array variable, or if the array contains
1696 no elements, then an empty list is returned.
1698 +*array names* 'arrayName ?pattern?'+::
1699 Returns a list containing the names of all of the elements
1700 in the array that match pattern. If pattern is omitted then
1701 the command returns all of the element names in the array.
1702 If pattern is specified, then only those elements whose
1703 names match pattern (using the matching rules of string
1704 match) are included. If there are no (matching) elements
1705 in the array, or if arrayName isn't the name of an array
1706 variable, then an empty string is returned.
1708 +*array set* 'arrayName list'+::
1709 Sets the values of one or more elements in arrayName. list
1710 must have a form like that returned by array get, consisting
1711 of an even number of elements. Each odd-numbered element
1712 in list is treated as an element name within arrayName, and
1713 the following element in list is used as a new value for
1714 that array element. If the variable arrayName does not
1715 already exist and list is empty, arrayName is created with
1716 an empty array value.
1718 +*array size* 'arrayName'+::
1719 Returns the number of elements in the array. If arrayName
1720 isn't the name of an array then 0 is returned.
1722 +*array unset* 'arrayName ?pattern?'+::
1723 Unsets all of the elements in the array that match pattern
1724 (using the matching rules of string match). If arrayName
1725 isn't the name of an array variable or there are no matching
1726 elements in the array, no error will be raised. If pattern
1727 is omitted and arrayName is an array variable, then the
1728 command unsets the entire array. The command always returns
1735 This command may be invoked only inside the body of a loop command
1736 such as `for` or `foreach` or `while`. It returns a +JIM_BREAK+ code
1737 to signal the innermost containing loop command to return immediately.
1741 +*case* 'string' ?in? 'patList body ?patList body ...?'+
1743 +*case* 'string' ?in? {'patList body ?patList body ...?'}+
1745 *Note* that the `switch` command should generally be preferred unless compatibility
1746 with Tcl 6.x is desired.
1748 Match +'string'+ against each of the +'patList'+ arguments
1749 in order. If one matches, then evaluate the following +'body'+ argument
1750 by passing it recursively to the Tcl interpreter, and return the result
1751 of that evaluation. Each +'patList'+ argument consists of a single
1752 pattern or list of patterns. Each pattern may contain any of the wild-cards
1753 described under `string match`.
1755 If a +'patList'+ argument is +default+, the corresponding body will be
1756 evaluated if no +'patList'+ matches +'string'+. If no +'patList'+ argument
1757 matches +'string'+ and no default is given, then the `case` command returns
1760 Two syntaxes are provided.
1762 The first uses a separate argument for each of the patterns and commands;
1763 this form is convenient if substitutions are desired on some of the
1764 patterns or commands.
1766 The second form places all of the patterns and commands together into
1767 a single argument; the argument must have proper list structure, with
1768 the elements of the list being the patterns and commands.
1770 The second form makes it easy to construct multi-line case commands,
1771 since the braces around the whole list make it unnecessary to include a
1772 backslash at the end of each line.
1774 Since the +'patList'+ arguments are in braces in the second form,
1775 no command or variable substitutions are performed on them; this makes
1776 the behaviour of the second form different than the first form in some
1779 Below are some examples of `case` commands:
1781 case abc in {a b} {format 1} default {format 2} a* {format 3}
1791 will return '1', and
1806 +*catch* ?-?no?'code \...'? ?--? 'command ?resultVarName? ?optionsVarName?'+
1808 The `catch` command may be used to prevent errors from aborting
1809 command interpretation. `catch` evaluates +'command'+, and returns a
1810 +JIM_OK+ code, regardless of any errors that might occur while
1811 executing +'command'+ (with the possible exception of +JIM_SIGNAL+ -
1814 The return value from `catch` is a decimal string giving the code
1815 returned by the Tcl interpreter after executing +'command'+. This
1816 will be '0' (+JIM_OK+) if there were no errors in +'command'+; otherwise
1817 it will have a non-zero value corresponding to one of the exceptional
1818 return codes (see jim.h for the definitions of code values, or the
1819 `info returncodes` command).
1821 If the +'resultVarName'+ argument is given, then it gives the name
1822 of a variable; `catch` will set the value of the variable to the
1823 string returned from +'command'+ (either a result or an error message).
1825 If the +'optionsVarName'+ argument is given, then it gives the name
1826 of a variable; `catch` will set the value of the variable to a
1827 dictionary. For any return code other than +JIM_RETURN+, the value
1828 for the key +-code+ will be set to the return code. For +JIM_RETURN+
1829 it will be set to the code given in `return -code`. Additionally,
1830 for the return code +JIM_ERR+, the value of the key +-errorinfo+
1831 will contain the current stack trace (the same result as `info stacktrace`),
1832 the value of the key +-errorcode+ will contain the
1833 same value as the global variable $::errorCode, and the value of
1834 the key +-level+ will be the current return level (see `return -level`).
1835 This can be useful to rethrow an error:
1837 if {[catch {...} msg opts]} {
1838 ...maybe do something with the error...
1840 return {*}$opts $msg
1843 Normally `catch` will +'not'+ catch any of the codes +JIM_EXIT+, +JIM_EVAL+ or +JIM_SIGNAL+.
1844 The set of codes which will be caught may be modified by specifying the one more codes before
1847 e.g. To catch +JIM_EXIT+ but not +JIM_BREAK+ or +JIM_CONTINUE+
1849 catch -exit -nobreak -nocontinue -- { ... }
1851 The use of +--+ is optional. It signifies that no more return code options follow.
1853 Note that if a signal marked as `signal handle` is caught with `catch -signal`, the return value
1854 (stored in +'resultVarName'+) is name of the signal caught.
1860 Change the current working directory to +'dirName'+.
1862 Returns an empty string.
1864 This command can potentially be disruptive to an application, so it may
1865 be removed in some applications.
1870 Returns the current time as seconds since the epoch.
1873 Returns the current time in "clicks", a system-dependent, high-resolution time.
1875 +*clock microseconds*+::
1876 Returns the current time in microseconds.
1878 +*clock milliseconds*+::
1879 Returns the current time in milliseconds.
1881 +*clock format* 'seconds' ?*-format* 'format?' ?*-gmt* 'boolean?'+::
1882 Format the given time (seconds since the epoch) according to the given
1883 format. See strftime(3) for supported formats.
1884 If no format is supplied, "%c" is used.
1886 If +'boolean'+ is true, processing is performed in UTC.
1887 If +'boolean'+ is false (the default), processing is performeed in the local time zone.
1889 +*clock scan* 'str' *-format* 'format' ?*-gmt* 'boolean?'+::
1890 Scan the given time string using the given format string.
1891 See strptime(3) for supported formats.
1892 See `clock format` for the handling of '-gmt'.
1900 Closes the file given by +'fileId'+.
1901 +'fileId'+ must be the return value from a previous invocation
1902 of the `open` command; after this command, it should not be
1909 Normally reference garbage collection is automatically performed periodically.
1910 However it may be run immediately with the `collect` command.
1912 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
1916 +*concat* 'arg ?arg \...?'+
1918 This command treats each argument as a list and concatenates them
1919 into a single list. It permits any number of arguments. For example,
1922 concat a b {c d e} {f {g h}}
1934 This command may be invoked only inside the body of a loop command such
1935 as `for` or `foreach` or `while`. It returns a +JIM_CONTINUE+ code to
1936 signal the innermost containing loop command to skip the remainder of
1937 the loop's body but continue with the next iteration of the loop.
1941 +*alias* 'args\...'+
1943 Similar to `alias` except it creates an anonymous procedure (lambda) instead of
1946 the following creates a local, unnamed alias for the command `info exists`.
1948 set e [local curry info exists]
1953 `curry` returns the name of the procedure.
1955 See also `proc`, `alias`, `lambda`, `local`.
1959 +*dict* 'option ?arg\...?'+
1961 Performs one of several operations on dictionary values.
1963 The +'option'+ argument determines what action is carried out by the
1964 command. The legal +'options'+ are:
1966 +*dict create* '?key value \...?'+::
1967 Create and return a new dictionary value that contains each of
1968 the key/value mappings listed as arguments (keys and values
1969 alternating, with each key being followed by its associated
1972 +*dict exists* 'dictionary key ?key \...?'+::
1973 Returns a boolean value indicating whether the given key (or path
1974 of keys through a set of nested dictionaries) exists in the given
1975 dictionary value. This returns a true value exactly when `dict get`
1976 on that path will succeed.
1978 +*dict get* 'dictionary ?key \...?'+::
1979 Given a dictionary value (first argument) and a key (second argument),
1980 this will retrieve the value for that key. Where several keys are
1981 supplied, the behaviour of the command shall be as if the result
1982 of "`dict get $dictVal $key`" was passed as the first argument to
1983 dict get with the remaining arguments as second (and possibly
1984 subsequent) arguments. This facilitates lookups in nested dictionaries.
1985 If no keys are provided, dict would return a list containing pairs
1986 of elements in a manner similar to array get. That is, the first
1987 element of each pair would be the key and the second element would
1988 be the value for that key. It is an error to attempt to retrieve
1989 a value for a key that is not present in the dictionary.
1991 +*dict keys* 'dictionary ?pattern?'+::
1992 Returns a list of the keys in the dictionary.
1993 If pattern is specified, then only those keys whose
1994 names match +'pattern'+ (using the matching rules of string
1995 match) are included.
1997 +*dict merge* ?'dictionary \...'?+::
1998 Return a dictionary that contains the contents of each of the
1999 +'dictionary'+ arguments. Where two (or more) dictionaries
2000 contain a mapping for the same key, the resulting dictionary
2001 maps that key to the value according to the last dictionary on
2002 the command line containing a mapping for that key.
2004 +*dict set* 'dictionaryName key ?key \...? value'+::
2005 This operation takes the +'name'+ of a variable containing a dictionary
2006 value and places an updated dictionary value in that variable
2007 containing a mapping from the given key to the given value. When
2008 multiple keys are present, this operation creates or updates a chain
2009 of nested dictionaries.
2011 +*dict size* 'dictionary'+::
2012 Return the number of key/value mappings in the given dictionary value.
2014 +*dict unset* 'dictionaryName key ?key \...? value'+::
2015 This operation (the companion to `dict set`) takes the name of a
2016 variable containing a dictionary value and places an updated
2017 dictionary value in that variable that does not contain a mapping
2018 for the given key. Where multiple keys are present, this describes
2019 a path through nested dictionaries to the mapping to remove. At
2020 least one key must be specified, but the last key on the key-path
2021 need not exist. All other components on the path must exist.
2023 +*dict with* 'dictionaryName key ?key \...? script'+::
2024 Execute the Tcl script in +'script'+ with the value for each
2025 key in +'dictionaryName'+ mapped to a variable with the same
2026 name. Where one or more keys are given, these indicate a chain
2027 of nested dictionaries, with the innermost dictionary being the
2028 one opened out for the execution of body. Making +'dictionaryName'+
2029 unreadable will make the updates to the dictionary be discarded,
2030 and this also happens if the contents of +'dictionaryName'+ are
2031 adjusted so that the chain of dictionaries no longer exists.
2032 The result of `dict with` is (unless some kind of error occurs)
2033 the result of the evaluation of body.
2035 The variables are mapped in the scope enclosing the `dict with`;
2036 it is recommended that this command only be used in a local
2037 scope (procedure). Because of this, the variables set by
2038 `dict with` will continue to exist after the command finishes (unless
2039 explicitly unset). Note that changes to the contents of +'dictionaryName'+
2040 only happen when +'script'+ terminates.
2042 +*dict for, values, incr, append, lappend, update, info, replace*+ to be documented...
2046 +*env* '?name? ?default?'+
2048 If +'name'+ is supplied, returns the value of +'name'+ from the initial
2049 environment (see getenv(3)). An error is returned if +'name'+ does not
2050 exist in the environment, unless +'default'+ is supplied - in which case
2051 that value is returned instead.
2053 If no arguments are supplied, returns a list of all environment variables
2054 and their values as +{name value \...}+
2056 See also the global variable +::env+
2064 Returns 1 if an end-of-file condition has occurred on +'fileId'+,
2067 +'fileId'+ must have been the return value from a previous call to `open`,
2068 or it may be +stdin+, +stdout+, or +stderr+ to refer to one of the
2069 standard I/O channels.
2073 +*error* 'message ?stacktrace?'+
2075 Returns a +JIM_ERR+ code, which causes command interpretation to be
2076 unwound. +'message'+ is a string that is returned to the application
2077 to indicate what went wrong.
2079 If the +'stacktrace'+ argument is provided and is non-empty,
2080 it is used to initialize the stacktrace.
2082 This feature is most useful in conjunction with the `catch` command:
2083 if a caught error cannot be handled successfully, +'stacktrace'+ can be used
2084 to return a stack trace reflecting the original point of occurrence
2089 error $errMsg [info stacktrace]
2091 See also `errorInfo`, `info stacktrace`, `catch` and `return`
2095 +*errorInfo* 'error ?stacktrace?'+
2097 Returns a human-readable representation of the given error message and stack trace.
2100 if {[catch {...} error]} {
2101 puts stderr [errorInfo $error [info stacktrace]]
2109 +*eval* 'arg ?arg\...?'+
2111 `eval` takes one or more arguments, which together comprise a Tcl
2112 command (or collection of Tcl commands separated by newlines in the
2113 usual way). `eval` concatenates all its arguments in the same
2114 fashion as the `concat` command, passes the concatenated string to the
2115 Tcl interpreter recursively, and returns the result of that
2116 evaluation (or any error generated by it).
2120 +*exec* 'arg ?arg\...?'+
2122 This command treats its arguments as the specification
2123 of one or more UNIX commands to execute as subprocesses.
2124 The commands take the form of a standard shell pipeline;
2125 +|+ arguments separate commands in the
2126 pipeline and cause standard output of the preceding command
2127 to be piped into standard input of the next command (or +|&+ for
2128 both standard output and standard error).
2130 Under normal conditions the result of the `exec` command
2131 consists of the standard output produced by the last command
2132 in the pipeline followed by the standard error output.
2134 If any of the commands writes to its standard error file,
2135 then this will be included in the result after the standard output
2136 of the last command.
2138 Note that unlike Tcl, data written to standard error does not cause
2139 `exec` to return an error.
2141 If any of the commands in the pipeline exit abnormally or
2142 are killed or suspended, then `exec` will return an error.
2143 If no standard error output was produced, or is redirected,
2144 the error message will include the normal result, as above,
2145 followed by error messages describing the abnormal terminations.
2147 If any standard error output was produced, these abnormal termination
2148 messages are suppressed.
2150 If the last character of the result or error message
2151 is a newline then that character is deleted from the result
2152 or error message for consistency with normal
2155 An +'arg'+ may have one of the following special forms:
2158 The standard output of the last command in the pipeline
2159 is redirected to the file. In this situation `exec`
2160 will normally return an empty string.
2163 As above, but append to the file.
2166 The standard output of the last command in the pipeline is
2167 redirected to the given (writable) file descriptor (e.g. stdout,
2168 stderr, or the result of `open`). In this situation `exec`
2169 will normally return an empty string.
2172 The standard error of the last command in the pipeline
2173 is redirected to the file.
2176 As above, but append to the file.
2179 The standard error of the last command in the pipeline is
2180 redirected to the given (writable) file descriptor.
2183 The standard error of the last command in the pipeline is
2184 redirected to the same file descriptor as the standard output.
2187 Both the standard output and standard error of the last command
2188 in the pipeline is redirected to the file.
2191 As above, but append to the file.
2194 The standard input of the first command in the pipeline
2195 is taken from the file.
2198 The standard input of the first command is taken as the
2199 given immediate value.
2202 The standard input of the first command in the pipeline
2203 is taken from the given (readable) file descriptor.
2205 If there is no redirection of standard input, standard error
2206 or standard output, these are connected to the corresponding
2207 input or output of the application.
2209 If the last +'arg'+ is +&+ then the command will be
2210 executed in background.
2211 In this case the standard output from the last command
2212 in the pipeline will
2213 go to the application's standard output unless
2214 redirected in the command, and error output from all
2215 the commands in the pipeline will go to the application's
2216 standard error file. The return value of exec in this case
2217 is a list of process ids (pids) in the pipeline.
2219 Each +'arg'+ becomes one word for a command, except for
2220 +|+, +<+, +<<+, +>+, and +&+ arguments, and the
2221 arguments that follow +<+, +<<+, and +>+.
2223 The first word in each command is taken as the command name;
2224 the directories in the PATH environment variable are searched for
2225 an executable by the given name.
2227 No `glob` expansion or other shell-like substitutions
2228 are performed on the arguments to commands.
2230 If the command fails, the global $::errorCode (and the -errorcode
2231 option in `catch`) will be set to a list, as follows:
2233 +*CHILDKILLED* 'pid sigName msg'+::
2234 This format is used when a child process has been killed
2235 because of a signal. The pid element will be the process's
2236 identifier (in decimal). The sigName element will be the
2237 symbolic name of the signal that caused the process to
2238 terminate; it will be one of the names from the include
2239 file signal.h, such as SIGPIPE. The msg element will be a
2240 short human-readable message describing the signal, such
2241 as "write on pipe with no readers" for SIGPIPE.
2243 +*CHILDSUSP* 'pid sigName msg'+::
2244 This format is used when a child process has been suspended
2245 because of a signal. The pid element will be the process's
2246 identifier, in decimal. The sigName element will be the
2247 symbolic name of the signal that caused the process to
2248 suspend; this will be one of the names from the include
2249 file signal.h, such as SIGTTIN. The msg element will be a
2250 short human-readable message describing the signal, such
2251 as "background tty read" for SIGTTIN.
2253 +*CHILDSTATUS* 'pid code'+::
2254 This format is used when a child process has exited with a
2255 non-zero exit status. The pid element will be the process's
2256 identifier (in decimal) and the code element will be the
2257 exit code returned by the process (also in decimal).
2259 The environment for the executed command is set from $::env (unless
2260 this variable is unset, in which case the original environment is used).
2264 +*exists ?-var|-proc|-command|-alias?* 'name'+
2266 Checks the existence of the given variable, procedure, command
2267 or alias respectively and returns 1 if it exists or 0 if not. This command
2268 provides a more simplified/convenient version of `info exists`,
2269 `info procs` and `info commands`.
2271 If the type is omitted, a type of '-var' is used. The type may be abbreviated.
2275 +*exit* '?returnCode?'+
2277 Terminate the process, returning +'returnCode'+ to the
2278 parent as the exit status.
2280 If +'returnCode'+ isn't specified then it defaults
2283 Note that exit can be caught with `catch`.
2289 Calls the expression processor to evaluate +'arg'+, and returns
2290 the result as a string. See the section EXPRESSIONS above.
2292 Note that Jim supports a shorthand syntax for `expr` as +$(\...)+
2293 The following two are identical.
2295 set x [expr {3 * 2 + 1}]
2300 +*file* 'option name ?arg\...?'+
2302 Operate on a file or a file name. +'name'+ is the name of a file.
2304 +'option'+ indicates what to do with the file name. Any unique
2305 abbreviation for +'option'+ is acceptable. The valid options are:
2307 +*file atime* 'name'+::
2308 Return a decimal string giving the time at which file +'name'+
2309 was last accessed. The time is measured in the standard UNIX
2310 fashion as seconds from a fixed starting time (often January 1, 1970).
2311 If the file doesn't exist or its access time cannot be queried then an
2314 +*file copy ?-force?* 'source target'+::
2315 Copies file +'source'+ to file +'target'+. The source file must exist.
2316 The target file must not exist, unless +-force+ is specified.
2318 +*file delete ?-force? ?--?* 'name\...'+::
2319 Deletes file or directory +'name'+. If the file or directory doesn't exist, nothing happens.
2320 If it can't be deleted, an error is generated. Non-empty directories will not be deleted
2321 unless the +-force+ options is given. In this case no errors will be generated, even
2322 if the file/directory can't be deleted. Use +'--'+ if there is any possibility of
2323 the first name being +'-force'+.
2325 +*file dirname* 'name'+::
2326 Return all of the characters in +'name'+ up to but not including
2327 the last slash character. If there are no slashes in +'name'+
2328 then return +.+ (a single dot). If the last slash in +'name'+ is its first
2329 character, then return +/+.
2331 +*file executable* 'name'+::
2332 Return '1' if file +'name'+ is executable by
2333 the current user, '0' otherwise.
2335 +*file exists* 'name'+::
2336 Return '1' if file +'name'+ exists and the current user has
2337 search privileges for the directories leading to it, '0' otherwise.
2339 +*file extension* 'name'+::
2340 Return all of the characters in +'name'+ after and including the
2341 last dot in +'name'+. If there is no dot in +'name'+ then return
2344 +*file isdirectory* 'name'+::
2345 Return '1' if file +'name'+ is a directory,
2348 +*file isfile* 'name'+::
2349 Return '1' if file +'name'+ is a regular file,
2352 +*file join* 'arg\...'+::
2353 Joins multiple path components. Note that if any components is
2354 an absolute path, the preceding components are ignored.
2355 Thus +"`file` join /tmp /root"+ returns +"/root"+.
2357 +*file link* ?*-hard|-symbolic*? 'newname target'+::
2358 Creates a hard link (default) or symbolic link from +'newname'+ to +'target'+.
2359 Note that the sense of this command is the opposite of `file rename` and `file copy`
2360 and also of `ln`, but this is compatible with Tcl.
2361 An error is returned if +'target'+ doesn't exist or +'newname'+ already exists.
2363 +*file lstat* 'name varName'+::
2364 Same as 'stat' option (see below) except uses the +'lstat'+
2365 kernel call instead of +'stat'+. This means that if +'name'+
2366 refers to a symbolic link the information returned in +'varName'+
2367 is for the link rather than the file it refers to. On systems that
2368 don't support symbolic links this option behaves exactly the same
2369 as the 'stat' option.
2371 +*file mkdir* 'dir1 ?dir2\...?'+::
2372 Creates each directory specified. For each pathname +'dir'+ specified,
2373 this command will create all non-existing parent directories
2374 as well as +'dir'+ itself. If an existing directory is specified,
2375 then no action is taken and no error is returned. Trying to
2376 overwrite an existing file with a directory will result in an
2377 error. Arguments are processed in the order specified, halting
2378 at the first error, if any.
2380 +*file mtime* 'name ?time?'+::
2381 Return a decimal string giving the time at which file +'name'+
2382 was last modified. The time is measured in the standard UNIX
2383 fashion as seconds from a fixed starting time (often January 1, 1970).
2384 If the file doesn't exist or its modified time cannot be queried then an
2385 error is generated. If +'time'+ is given, sets the modification time
2386 of the file to the given value.
2388 +*file mtimeus* 'name ?time_us?'+::
2389 As for `file mtime` except the time value is in microseconds
2390 since the epoch (see also `clock microseconds`).
2391 Note that some platforms and some filesystems don't support high
2392 resolution timestamps for files.
2394 +*file normalize* 'name'+::
2395 Return the normalized path of +'name'+. See 'realpath(3)'.
2397 +*file owned* 'name'+::
2398 Return '1' if file +'name'+ is owned by the current user,
2401 +*file readable* 'name'+::
2402 Return '1' if file +'name'+ is readable by
2403 the current user, '0' otherwise.
2405 +*file readlink* 'name'+::
2406 Returns the value of the symbolic link given by +'name'+ (i.e. the
2407 name of the file it points to). If
2408 +'name'+ isn't a symbolic link or its value cannot be read, then
2409 an error is returned. On systems that don't support symbolic links
2410 this option is undefined.
2412 +*file rename* ?*-force*? 'oldname' 'newname'+::
2413 Renames the file from the old name to the new name.
2414 If +'newname'+ already exists, an error is returned unless +'-force'+ is
2417 +*file rootname* 'name'+::
2418 Return all of the characters in +'name'+ up to but not including
2419 the last '.' character in the name. If +'name'+ doesn't contain
2420 a dot, then return +'name'+.
2422 +*file split* 'name'+::
2423 Returns a list whose elements are the path components in +'name'+.
2424 The first element of the list will have the same path type as
2425 +'name'+. All other elements will be relative. Path separators
2428 +*file stat* 'name ?varName?'+::
2429 Invoke the 'stat' kernel call on +'name'+, and return the result
2430 as a dictionary with the following keys: 'atime',
2431 'ctime', 'dev', 'gid', 'ino', 'mode', 'mtime',
2432 'nlink', 'size', 'type', 'uid', 'mtimeus' (if supported - see `file mtimeus`)
2433 Each element except 'type' is a decimal string with the value of
2434 the corresponding field from the 'stat' return structure; see the
2435 manual entry for 'stat' for details on the meanings of the values.
2436 The 'type' element gives the type of the file in the same form
2437 returned by the command `file type`.
2438 If +'varName'+ is specified, it is taken to be the name of an array
2439 variable and the values are also stored into the array.
2441 +*file tail* 'name'+::
2442 Return all of the characters in +'name'+ after the last slash.
2443 If +'name'+ contains no slashes then return +'name'+.
2445 +*file tempfile* '?template?'+::
2446 Creates and returns the name of a unique temporary file. If +'template'+ is omitted, a
2447 default template will be used to place the file in /tmp. See 'mkstemp(3)' for
2448 the format of the template and security concerns.
2450 +*file type* 'name'+::
2451 Returns a string giving the type of file +'name'+, which will be
2452 one of +file+, +directory+, +characterSpecial+,
2453 +blockSpecial+, +fifo+, +link+, or +socket+.
2455 +*file writable* 'name'+::
2456 Return '1' if file +'name'+ is writable by
2457 the current user, '0' otherwise.
2459 The `file` commands that return 0/1 results are often used in
2460 conditional or looping commands, for example:
2462 if {![file exists foo]} {
2463 error {bad file name}
2470 +*finalize* 'reference ?command?'+
2472 If +'command'+ is omitted, returns the finalizer command for the given reference.
2474 Otherwise, sets a new finalizer command for the given reference. +'command'+ may be
2475 the empty string to remove the current finalizer.
2477 The reference must be a valid reference create with the `ref`
2480 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2488 Flushes any output that has been buffered for +'fileId'+. +'fileId'+ must
2489 have been the return value from a previous call to `open`, or it may be
2490 +stdout+ or +stderr+ to access one of the standard I/O streams; it must
2491 refer to a file that was opened for writing. This command returns an
2496 +*for* 'start test next body'+
2498 `for` is a looping command, similar in structure to the C `for` statement.
2499 The +'start'+, +'next'+, and +'body'+ arguments must be Tcl command strings,
2500 and +'test'+ is an expression string.
2502 The `for` command first invokes the Tcl interpreter to execute +'start'+.
2503 Then it repeatedly evaluates +'test'+ as an expression; if the result is
2504 non-zero it invokes the Tcl interpreter on +'body'+, then invokes the Tcl
2505 interpreter on +'next'+, then repeats the loop. The command terminates
2506 when +'test'+ evaluates to 0.
2508 If a `continue` command is invoked within +'body'+ then any remaining
2509 commands in the current execution of +'body'+ are skipped; processing
2510 continues by invoking the Tcl interpreter on +'next'+, then evaluating
2511 +'test'+, and so on.
2513 If a `break` command is invoked within +'body'+ or +'next'+, then the `for`
2514 command will return immediately.
2516 The operation of `break` and `continue` are similar to the corresponding
2519 `for` returns an empty string.
2523 +*foreach* 'varName list body'+
2525 +*foreach* 'varList list ?varList2 list2 \...? body'+
2527 In this command, +'varName'+ is the name of a variable, +'list'+
2528 is a list of values to assign to +'varName'+, and +'body'+ is a
2529 collection of Tcl commands.
2531 For each field in +'list'+ (in order from left to right), `foreach` assigns
2532 the contents of the field to +'varName'+ (as if the `lindex` command
2533 had been used to extract the field), then calls the Tcl interpreter to
2536 If instead of being a simple name, +'varList'+ is used, multiple assignments
2537 are made each time through the loop, one for each element of +'varList'+.
2539 For example, if there are two elements in +'varList'+ and six elements in
2540 the list, the loop will be executed three times.
2542 If the length of the list doesn't evenly divide by the number of elements
2543 in +'varList'+, the value of the remaining variables in the last iteration
2544 of the loop are undefined.
2546 The `break` and `continue` statements may be invoked inside +'body'+,
2547 with the same effect as in the `for` command.
2549 `foreach` returns an empty string.
2553 +*format* 'formatString ?arg \...?'+
2555 This command generates a formatted string in the same way as the
2556 C 'sprintf' procedure (it uses 'sprintf' in its
2557 implementation). +'formatString'+ indicates how to format
2558 the result, using +%+ fields as in 'sprintf', and the additional
2559 arguments, if any, provide values to be substituted into the result.
2561 All of the 'sprintf' options are valid; see the 'sprintf'
2562 man page for details. Each +'arg'+ must match the expected type
2563 from the +%+ field in +'formatString'+; the `format` command
2564 converts each argument to the correct type (floating, integer, etc.)
2565 before passing it to 'sprintf' for formatting.
2567 The only unusual conversion is for +%c+; in this case the argument
2568 must be a decimal string, which will then be converted to the corresponding
2569 ASCII (or UTF-8) character value.
2571 In addition, Jim Tcl provides basic support for conversion to binary with +%b+.
2573 `format` does backslash substitution on its +'formatString'+
2574 argument, so backslash sequences in +'formatString'+ will be handled
2575 correctly even if the argument is in braces.
2577 The return value from `format` is the formatted string.
2581 +*getref* 'reference'+
2583 Returns the string associated with +'reference'+. The reference must
2584 be a valid reference create with the `ref` command.
2586 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2590 +*gets* 'fileId ?varName?'+
2592 +'fileId' *gets* '?varName?'+
2594 Reads the next line from the file given by +'fileId'+ and discards
2595 the terminating newline character.
2597 If +'varName'+ is specified, then the line is placed in the variable
2598 by that name and the return value is a count of the number of characters
2599 read (not including the newline).
2601 If the end of the file is reached before reading
2602 any characters then -1 is returned and +'varName'+ is set to an
2605 If +'varName'+ is not specified then the return value will be
2606 the line (minus the newline character) or an empty string if
2607 the end of the file is reached before reading any characters.
2609 An empty string will also be returned if a line contains no characters
2610 except the newline, so `eof` may have to be used to determine
2611 what really happened.
2613 If the last character in the file is not a newline character, then
2614 `gets` behaves as if there were an additional newline character
2615 at the end of the file.
2617 +'fileId'+ must be +stdin+ or the return value from a previous
2618 call to `open`; it must refer to a file that was opened
2623 +*glob* ?*-nocomplain*? ?*-directory* 'dir'? ?*-tails*? ?*--*? 'pattern ?pattern \...?'+
2625 This command performs filename globbing, using csh rules. The returned
2626 value from `glob` is the list of expanded filenames.
2628 If +-nocomplain+ is specified as the first argument then an empty
2629 list may be returned; otherwise an error is returned if the expanded
2630 list is empty. The +-nocomplain+ argument must be provided
2631 exactly: an abbreviation will not be accepted.
2633 If +-directory+ is given, the +'dir'+ is understood to contain a
2634 directory name to search in. This allows globbing inside directories
2635 whose names may contain glob-sensitive characters. The returned names
2636 include the directory name unless +'-tails'+ is specified.
2638 If +'-tails'+ is specified, along with +-directory+, the returned names
2639 are relative to the given directory.
2644 +*global* 'varName ?varName \...?'+
2646 This command is ignored unless a Tcl procedure is being interpreted.
2647 If so, then it declares each given +'varName'+ to be a global variable
2648 rather than a local one. For the duration of the current procedure
2649 (and only while executing in the current procedure), any reference to
2650 +'varName'+ will be bound to a global variable instead
2653 An alternative to using `global` is to use the +::+ prefix
2654 to explicitly name a variable in the global scope.
2658 +*if* 'expr1' ?*then*? 'body1' *elseif* 'expr2' ?*then*? 'body2' *elseif* \... ?*else*? ?'bodyN'?+
2660 The `if` command evaluates +'expr1'+ as an expression (in the same way
2661 that `expr` evaluates its argument). The value of the expression must
2662 be numeric; if it is non-zero then +'body1'+ is executed by passing it to
2663 the Tcl interpreter.
2665 Otherwise +'expr2'+ is evaluated as an expression and if it is non-zero
2666 then +'body2'+ is executed, and so on.
2668 If none of the expressions evaluates to non-zero then +'bodyN'+ is executed.
2670 The +then+ and +else+ arguments are optional "noise words" to make the
2671 command easier to read.
2673 There may be any number of +elseif+ clauses, including zero. +'bodyN'+
2674 may also be omitted as long as +else+ is omitted too.
2676 The return value from the command is the result of the body script that
2677 was executed, or an empty string if none of the expressions was non-zero
2678 and there was no +'bodyN'+.
2682 +*incr* 'varName ?increment?'+
2684 Increment the value stored in the variable whose name is +'varName'+.
2685 The value of the variable must be integral.
2687 If +'increment'+ is supplied then its value (which must be an
2688 integer) is added to the value of variable +'varName'+; otherwise
2689 1 is added to +'varName'+.
2691 The new value is stored as a decimal string in variable +'varName'+
2692 and also returned as result.
2694 If the variable does not exist, the variable is implicitly created
2695 and set to +0+ first.
2700 +*info* 'option ?arg\...?'+::
2702 Provide information about various internals to the Tcl interpreter.
2703 The legal +'option'+'s (which may be abbreviated) are:
2705 +*info args* 'procname'+::
2706 Returns a list containing the names of the arguments to procedure
2707 +'procname'+, in order. +'procname'+ must be the name of a
2708 Tcl command procedure.
2710 +*info alias* 'command'+::
2711 +'command'+ must be an alias created with `alias`. In which case the target
2712 command and arguments, as passed to `alias` are returned. See `exists -alias`
2714 +*info body* 'procname'+::
2715 Returns the body of procedure +'procname'+. +'procname'+ must be
2716 the name of a Tcl command procedure.
2719 Returns a list of all open file handles from `open` or `socket`
2721 +*info commands* ?'pattern'?+::
2722 If +'pattern'+ isn't specified, returns a list of names of all the
2723 Tcl commands, including both the built-in commands written in C and
2724 the command procedures defined using the `proc` command.
2725 If +'pattern'+ is specified, only those names matching +'pattern'+
2726 are returned. Matching is determined using the same rules as for
2729 +*info complete* 'command' ?'missing'?+::
2730 Returns 1 if +'command'+ is a complete Tcl command in the sense of
2731 having no unclosed quotes, braces, brackets or array element names,
2732 If the command doesn't appear to be complete then 0 is returned.
2733 This command is typically used in line-oriented input environments
2734 to allow users to type in commands that span multiple lines; if the
2735 command isn't complete, the script can delay evaluating it until additional
2736 lines have been typed to complete the command. If +'varName'+ is specified, the
2737 missing character is stored in the variable with that name.
2739 +*info exists* 'varName'+::
2740 Returns '1' if the variable named +'varName'+ exists in the
2741 current context (either as a global or local variable), returns '0'
2744 +*info frame* ?'number'?+::
2745 If +'number'+ is not specified, this command returns a number
2746 which is the same result as `info level` - the current stack frame level.
2747 If +'number'+ is specified, then the result is a list consisting of the procedure,
2748 filename and line number for the procedure call at level +'number'+ on the stack.
2749 If +'number'+ is positive then it selects a particular stack level (1 refers
2750 to the top-most active procedure, 2 to the procedure it called, and
2751 so on); otherwise it gives a level relative to the current level
2752 (0 refers to the current procedure, -1 to its caller, and so on).
2753 The level has an identical meaning to `info level`.
2755 +*info globals* ?'pattern'?+::
2756 If +'pattern'+ isn't specified, returns a list of all the names
2757 of currently-defined global variables.
2758 If +'pattern'+ is specified, only those names matching +'pattern'+
2759 are returned. Matching is determined using the same rules as for
2763 An alias for `os.gethostname` for compatibility with Tcl 6.x
2765 +*info level* ?'number'?+::
2766 If +'number'+ is not specified, this command returns a number
2767 giving the stack level of the invoking procedure, or 0 if the
2768 command is invoked at top-level. If +'number'+ is specified,
2769 then the result is a list consisting of the name and arguments for the
2770 procedure call at level +'number'+ on the stack. If +'number'+
2771 is positive then it selects a particular stack level (1 refers
2772 to the top-most active procedure, 2 to the procedure it called, and
2773 so on); otherwise it gives a level relative to the current level
2774 (0 refers to the current procedure, -1 to its caller, and so on).
2775 See the `uplevel` command for more information on what stack
2778 +*info locals* ?'pattern'?+::
2779 If +'pattern'+ isn't specified, returns a list of all the names
2780 of currently-defined local variables, including arguments to the
2781 current procedure, if any. Variables defined with the `global`
2782 and `upvar` commands will not be returned. If +'pattern'+ is
2783 specified, only those names matching +'pattern'+ are returned.
2784 Matching is determined using the same rules as for `string match`.
2786 +*info nameofexecutable*+::
2787 Returns the name of the binary file from which the application
2788 was invoked. A full path will be returned, unless the path
2789 can't be determined, in which case the empty string will be returned.
2791 +*info procs* ?'pattern'?+::
2792 If +'pattern'+ isn't specified, returns a list of all the
2793 names of Tcl command procedures.
2794 If +'pattern'+ is specified, only those names matching +'pattern'+
2795 are returned. Matching is determined using the same rules as for
2798 +*info references*+::
2799 Returns a list of all references which have not yet been garbage
2802 +*info returncodes* ?'code'?+::
2803 Returns a list representing the mapping of standard return codes
2804 to names. e.g. +{0 ok 1 error 2 return \...}+. If a code is given,
2805 instead returns the name for the given code.
2808 If a Tcl script file is currently being evaluated (i.e. there is a
2809 call to 'Jim_EvalFile' active or there is an active invocation
2810 of the `source` command), then this command returns the name
2811 of the innermost file being processed. Otherwise the command returns an
2814 +*info source* 'script ?filename line?'+::
2815 With a single argument, returns the original source location of the given script as a list of
2816 +{filename linenumber}+. If the source location can't be determined, the
2817 list +{{} 0}+ is returned. If +'filename'+ and +'line'+ are given, returns a copy
2818 of +'script'+ with the associate source information. This can be useful to produce
2819 useful messages from `eval`, etc. if the original source information may be lost.
2821 +*info stacktrace*+::
2822 After an error is caught with `catch`, returns the stack trace as a list
2823 of +{procedure filename line \...}+.
2825 +*info statics* 'procname'+::
2826 Returns a dictionary of the static variables of procedure
2827 +'procname'+. +'procname'+ must be the name of a Tcl command
2828 procedure. An empty dictionary is returned if the procedure has
2829 no static variables.
2832 Returns the version number for this version of Jim in the form +*x.yy*+.
2834 +*info vars* ?'pattern'?+::
2835 If +'pattern'+ isn't specified,
2836 returns a list of all the names of currently-visible variables, including
2837 both locals and currently-visible globals.
2838 If +'pattern'+ is specified, only those names matching +'pattern'+
2839 are returned. Matching is determined using the same rules as for
2844 +*join* 'list ?joinString?'+
2846 The +'list'+ argument must be a valid Tcl list. This command returns the
2847 string formed by joining all of the elements of +'list'+ together with
2848 +'joinString'+ separating each adjacent pair of elements.
2850 The +'joinString'+ argument defaults to a space character.
2854 +*kill* ?'SIG'|*-0*? 'pid'+
2856 Sends the given signal to the process identified by +'pid'+.
2858 The signal may be specified by name or number in one of the following forms:
2866 The signal name may be in either upper or lower case.
2868 The special signal name +-0+ simply checks that a signal +'could'+ be sent.
2870 If no signal is specified, SIGTERM is used.
2872 An error is raised if the signal could not be delivered.
2876 +*lambda* 'args ?statics? body'+
2878 The `lambda` command is identical to `proc`, except rather than
2879 creating a named procedure, it creates an anonymous procedure and returns
2880 the name of the procedure.
2882 See `proc` and GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2886 +*lappend* 'varName value ?value value \...?'+
2888 Treat the variable given by +'varName'+ as a list and append each of
2889 the +'value'+ arguments to that list as a separate element, with spaces
2892 If +'varName'+ doesn't exist, it is created as a list with elements given
2893 by the +'value'+ arguments. `lappend` is similar to `append` except that
2894 each +'value'+ is appended as a list element rather than raw text.
2896 This command provides a relatively efficient way to build up large lists.
2901 is much more efficient than
2903 set a [concat $a [list $b]]
2909 +*lassign* 'list varName ?varName \...?'+
2911 This command treats the value +'list'+ as a list and assigns successive elements from that list to
2912 the variables given by the +'varName'+ arguments in order. If there are more variable names than
2913 list elements, the remaining variables are set to the empty string. If there are more list elements
2914 than variables, a list of unassigned elements is returned.
2916 jim> lassign {1 2 3} a b; puts a=$a,b=$b
2922 +*local* 'cmd ?arg\...?'+
2924 First, `local` evaluates +'cmd'+ with the given arguments. The return value must
2925 be the name of an existing command, which is marked as having local scope.
2926 This means that when the current procedure exits, the specified
2927 command is deleted. This can be useful with `lambda`, local procedures or
2928 to automatically close a filehandle.
2930 In addition, if a command already exists with the same name,
2931 the existing command will be kept rather than deleted, and may be called
2932 via `upcall`. The previous command will be restored when the current
2933 procedure exits. See `upcall` for more details.
2935 In this example, a local procedure is created. Note that the procedure
2936 continues to have global scope while it is active.
2939 # proc ... returns "inner" which is marked local
2940 local proc inner {} {
2941 # will be deleted when 'outer' exits
2948 In this example, the lambda is deleted at the end of the procedure rather
2949 than waiting until garbage collection.
2952 set x [lambda inner {args} {
2953 # will be deleted when 'outer' exits
2955 # Use 'function' here which simply returns $x
2964 +*loop* 'var first limit ?incr? body'+
2966 Similar to `for` except simpler and possibly more efficient.
2967 With a positive increment, equivalent to:
2969 for {set var $first} {$var < $limit} {incr var $incr} $body
2971 If +'incr'+ is not specified, 1 is used.
2972 Note that setting the loop variable inside the loop does not
2973 affect the loop count.
2977 +*lindex* 'list ?index ...?'+
2979 Treats +'list'+ as a Tcl list and returns element +'index'+ from it
2980 (0 refers to the first element of the list).
2981 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2983 In extracting the element, +'lindex'+ observes the same rules concerning
2984 braces and quotes and backslashes as the Tcl command interpreter; however,
2985 variable substitution and command substitution do not occur.
2987 If no index values are given, simply returns +'list'+
2989 If +'index'+ is negative or greater than or equal to the number of elements
2990 in +'list'+, then an empty string is returned.
2992 If additional index arguments are supplied, then each argument is
2993 used in turn to select an element from the previous indexing
2994 operation, allowing the script to select elements from sublists.
2998 +*linsert* 'list index element ?element element \...?'+
3000 This command produces a new list from +'list'+ by inserting all
3001 of the +'element'+ arguments just before the element +'index'+
3002 of +'list'+. Each +'element'+ argument will become
3003 a separate element of the new list. If +'index'+ is less than
3004 or equal to zero, then the new elements are inserted at the
3005 beginning of the list. If +'index'+ is greater than or equal
3006 to the number of elements in the list, then the new elements are
3007 appended to the list.
3009 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
3014 +*list* 'arg ?arg \...?'+
3016 This command returns a list comprised of all the arguments, +'arg'+. Braces
3017 and backslashes get added as necessary, so that the `lindex` command
3018 may be used on the result to re-extract the original arguments, and also
3019 so that `eval` may be used to execute the resulting list, with
3020 +'arg1'+ comprising the command's name and the other args comprising
3021 its arguments. `list` produces slightly different results than
3022 `concat`: `concat` removes one level of grouping before forming
3023 the list, while `list` works directly from the original arguments.
3024 For example, the command
3026 list a b {c d e} {f {g h}}
3030 a b {c d e} {f {g h}}
3032 while `concat` with the same arguments will return
3040 Treats +'list'+ as a list and returns a decimal string giving
3041 the number of elements in it.
3045 +*lset* 'varName ?index ..? newValue'+
3047 Sets an element in a list.
3049 The `lset` command accepts a parameter, +'varName'+, which it interprets
3050 as the name of a variable containing a Tcl list. It also accepts
3051 zero or more indices into the list. Finally, it accepts a new value
3052 for an element of varName. If no indices are presented, the command
3055 lset varName newValue
3057 In this case, newValue replaces the old value of the variable
3060 When presented with a single index, the `lset` command
3061 treats the content of the varName variable as a Tcl list. It addresses
3062 the index'th element in it (0 refers to the first element of the
3063 list). When interpreting the list, `lset` observes the same rules
3064 concerning braces and quotes and backslashes as the Tcl command
3065 interpreter; however, variable substitution and command substitution
3066 do not occur. The command constructs a new list in which the
3067 designated element is replaced with newValue. This new list is
3068 stored in the variable varName, and is also the return value from
3071 If index is negative or greater than or equal to the number of
3072 elements in $varName, then an error occurs.
3074 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
3076 If additional index arguments are supplied, then each argument is
3077 used in turn to address an element within a sublist designated by
3078 the previous indexing operation, allowing the script to alter
3079 elements in sublists. The command,
3083 replaces element 2 of sublist 1 with +'newValue'+.
3085 The integer appearing in each index argument must be greater than
3086 or equal to zero. The integer appearing in each index argument must
3087 be strictly less than the length of the corresponding list. In other
3088 words, the `lset` command cannot change the size of a list. If an
3089 index is outside the permitted range, an error is reported.
3094 +*lmap* 'varName list body'+
3096 +*lmap* 'varList list ?varList2 list2 \...? body'+
3098 `lmap` is a "collecting" `foreach` which returns a list of its results.
3102 jim> lmap i {1 2 3 4 5} {expr $i*$i}
3104 jim> lmap a {1 2 3} b {A B C} {list $a $b}
3107 If the body invokes `continue`, no value is added for this iteration.
3108 If the body invokes `break`, the loop ends and no more values are added.
3114 Loads the dynamic extension, +'filename'+. Generally the filename should have
3115 the extension +.so+. The initialisation function for the module must be based
3116 on the name of the file. For example loading +hwaccess.so+ will invoke
3117 the initialisation function, +Jim_hwaccessInit+. Normally the `load` command
3118 should not be used directly. Instead it is invoked automatically by `package require`.
3122 +*lrange* 'list first last'+
3124 +'list'+ must be a valid Tcl list. This command will return a new
3125 list consisting of elements +'first'+ through +'last'+, inclusive.
3127 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3129 If +'last'+ is greater than or equal to the number of elements
3130 in the list, then it is treated as if it were +end+.
3132 If +'first'+ is greater than +'last'+ then an empty string
3135 Note: +"`lrange` 'list first first'"+ does not always produce the
3136 same result as +"`lindex` 'list first'"+ (although it often does
3137 for simple fields that aren't enclosed in braces); it does, however,
3138 produce exactly the same results as +"`list` [`lindex` 'list first']"+
3143 +*lreplace* 'list first last ?element element \...?'+
3145 Returns a new list formed by replacing one or more elements of
3146 +'list'+ with the +'element'+ arguments.
3148 +'first'+ gives the index in +'list'+ of the first element
3151 If +'first'+ is less than zero then it refers to the first
3152 element of +'list'+; the element indicated by +'first'+
3153 must exist in the list.
3155 +'last'+ gives the index in +'list'+ of the last element
3156 to be replaced; it must be greater than or equal to +'first'+.
3158 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3160 The +'element'+ arguments specify zero or more new arguments to
3161 be added to the list in place of those that were deleted.
3163 Each +'element'+ argument will become a separate element of
3166 If no +'element'+ arguments are specified, then the elements
3167 between +'first'+ and +'last'+ are simply deleted.
3171 +*lrepeat* 'number element1 ?element2 \...?'+
3173 Build a list by repeating elements +'number'+ times (which must be
3174 a positive integer).
3183 Returns the list in reverse order.
3185 jim> lreverse {1 2 3}
3190 +*lsearch* '?options? list pattern'+
3192 This command searches the elements +'list'+ to see if one of them matches +'pattern'+. If so, the
3193 command returns the index of the first matching element (unless the options +-all+, +-inline+ or +-bool+ are
3194 specified.) If not, the command returns -1. The option arguments indicates how the elements of
3195 the list are to be matched against pattern and must have one of the values below:
3197 *Note* that this command is different from Tcl in that default match type is +-exact+ rather than +-glob+.
3200 +'pattern'+ is a literal string that is compared for exact equality against each list element.
3201 This is the default.
3204 +'pattern'+ is a glob-style pattern which is matched against each list element using the same
3205 rules as the string match command.
3208 +'pattern'+ is treated as a regular expression and matched against each list element using
3209 the rules described by `regexp`.
3211 +*-command* 'cmdname'+::
3212 +'cmdname'+ is a command which is used to match the pattern against each element of the
3213 list. It is invoked as +'cmdname' ?*-nocase*? 'pattern listvalue'+ and should return 1
3214 for a match, or 0 for no match.
3217 Changes the result to be the list of all matching indices (or all matching values if
3218 +-inline+ is specified as well). If indices are returned, the indices will be in numeric
3219 order. If values are returned, the order of the values will be the order of those values
3220 within the input list.
3223 The matching value is returned instead of its index (or an empty string if no value
3224 matches). If +-all+ is also specified, then the result of the command is the list of all
3225 values that matched. The +-inline+ and +-bool+ options are mutually exclusive.
3228 Changes the result to '1' if a match was found, or '0' otherwise. If +-all+ is also specified,
3229 the result will be a list of '0' and '1' for each element of the list depending upon whether
3230 the corresponding element matches. The +-inline+ and +-bool+ options are mutually exclusive.
3233 This negates the sense of the match, returning the index (or value
3234 if +-inline+ is specified) of the first non-matching value in the
3235 list. If +-bool+ is also specified, the '0' will be returned if a
3236 match is found, or '1' otherwise. If +-all+ is also specified,
3237 non-matches will be returned rather than matches.
3240 Causes comparisons to be handled in a case-insensitive manner.
3244 +*lsort* ?*-index* 'listindex'? ?*-nocase|-integer|-real|-command* 'cmdname'? ?*-unique*? ?*-decreasing*|*-increasing*? 'list'+
3246 Sort the elements of +'list'+, returning a new list in sorted order.
3247 By default, ASCII (or UTF-8) sorting is used, with the result in increasing order.
3249 If +-nocase+ is specified, comparisons are case-insensitive.
3251 If +-integer+ is specified, numeric sorting is used.
3253 If +-real+ is specified, floating point number sorting is used.
3255 If +-command 'cmdname'+ is specified, +'cmdname'+ is treated as a command
3256 name. For each comparison, +'cmdname $value1 $value2+' is called which
3257 should compare the values and return an integer less than, equal
3258 to, or greater than zero if the +'$value1'+ is to be considered less
3259 than, equal to, or greater than +'$value2'+, respectively.
3261 If +-decreasing+ is specified, the resulting list is in the opposite
3262 order to what it would be otherwise. +-increasing+ is the default.
3264 If +-unique+ is specified, then only the last set of duplicate elements found in the list will be retained.
3265 Note that duplicates are determined relative to the comparison used in the sort. Thus if +-index 0+ is used,
3266 +{1 a}+ and +{1 b}+ would be considered duplicates and only the second element, +{1 b}+, would be retained.
3268 If +-index 'listindex'+ is specified, each element of the list is treated as a list and
3269 the given index is extracted from the list for comparison. The list index may
3270 be any valid list index, such as +1+, +end+ or +end-2+.
3276 This command is a simple helper command to add a script to the '+$jim::defer+' variable
3277 that will run when the current proc or interpreter exits. For example:
3279 jim> proc a {} { defer {puts "Leaving a"}; puts "Exit" }
3284 If the '+$jim::defer+' variable exists, it is treated as a list of scripts to run
3285 when the proc or interpreter exits.
3289 +*open* 'fileName ?access?'+
3291 +*open* '|command-pipeline ?access?'+
3293 Opens a file and returns an identifier
3294 that may be used in future invocations
3295 of commands like `read`, `puts`, and `close`.
3296 +'fileName'+ gives the name of the file to open.
3298 The +'access'+ argument indicates the way in which the file is to be accessed.
3299 It may have any of the following values:
3302 Open the file for reading only; the file must already exist.
3305 Open the file for both reading and writing; the file must
3309 Open the file for writing only. Truncate it if it exists. If it doesn't
3310 exist, create a new file.
3313 Open the file for reading and writing. Truncate it if it exists.
3314 If it doesn't exist, create a new file.
3317 Open the file for writing only. The file must already exist, and the file
3318 is positioned so that new data is appended to the file.
3321 Open the file for reading and writing. If the file doesn't
3322 exist, create a new empty file. Set the initial access position
3323 to the end of the file.
3325 +'access'+ defaults to 'r'.
3327 If a file is opened for both reading and writing, then `seek`
3328 must be invoked between a read and a write, or vice versa.
3330 If the first character of +'fileName'+ is "|" then the remaining
3331 characters of +'fileName'+ are treated as a list of arguments that
3332 describe a command pipeline to invoke, in the same style as the
3333 arguments for exec. In this case, the channel identifier returned
3334 by open may be used to write to the command's input pipe or read
3335 from its output pipe, depending on the value of +'access'+. If write-only
3336 access is used (e.g. +'access'+ is 'w'), then standard output for the
3337 pipeline is directed to the current standard output unless overridden
3338 by the command. If read-only access is used (e.g. +'access'+ is r),
3339 standard input for the pipeline is taken from the current standard
3340 input unless overridden by the command.
3342 The `pid` command may be used to return the process ids of the commands
3343 forming the command pipeline.
3345 See also `socket`, `pid`, `exec`
3349 +*package provide* 'name ?version?'+
3351 Indicates that the current script provides the package named +'name'+.
3352 If no version is specified, '1.0' is used.
3354 Any script which provides a package may include this statement
3355 as the first statement, although it is not required.
3357 +*package require* 'name ?version?'*+
3359 Searches for the package with the given +'name'+ by examining each path
3360 in '$::auto_path' and trying to load '$path/$name.so' as a dynamic extension,
3361 or '$path/$name.tcl' as a script package.
3363 The first such file which is found is considered to provide the package.
3364 (The version number is ignored).
3366 If '$name.so' exists, it is loaded with the `load` command,
3367 otherwise if '$name.tcl' exists it is loaded with the `source` command.
3369 If `load` or `source` fails, `package require` will fail immediately.
3370 No further attempt will be made to locate the file.
3378 The first form returns the process identifier of the current process.
3380 The second form accepts a handle returned by `open` and returns a list
3381 of the process ids forming the pipeline in the same form as `exec ... &`.
3382 If 'fileId' represents a regular file handle rather than a command pipeline,
3383 the empty string is returned instead.
3385 See also `open`, `exec`
3389 +*proc* 'name args ?statics? body'+
3391 The `proc` command creates a new Tcl command procedure, +'name'+.
3392 When the new command is invoked, the contents of +'body'+ will be executed.
3393 Tcl interpreter. +'args'+ specifies the formal arguments to the procedure.
3394 If specified, +'statics'+, declares static variables which are bound to the
3397 See PROCEDURES for detailed information about Tcl procedures.
3399 The `proc` command returns +'name'+ (which is useful with `local`).
3401 When a procedure is invoked, the procedure's return value is the
3402 value specified in a `return` command. If the procedure doesn't
3403 execute an explicit `return`, then its return value is the value
3404 of the last command executed in the procedure's body.
3406 If an error occurs while executing the procedure body, then the
3407 procedure-as-a-whole will return that same error.
3411 +*puts* ?*-nonewline*? '?fileId? string'+
3413 +'fileId' *puts* ?*-nonewline*? 'string'+
3415 Writes the characters given by +'string'+ to the file given
3416 by +'fileId'+. +'fileId'+ must have been the return
3417 value from a previous call to `open`, or it may be
3418 +stdout+ or +stderr+ to refer to one of the standard I/O
3419 channels; it must refer to a file that was opened for
3422 In the first form, if no +'fileId'+ is specified then it defaults to +stdout+.
3423 `puts` normally outputs a newline character after +'string'+,
3424 but this feature may be suppressed by specifying the +-nonewline+
3427 Output to files is buffered internally by Tcl; the `flush`
3428 command may be used to force buffered characters to be output.
3432 Creates a pair of `aio` channels and returns the handles as a list: +{read write}+
3436 # Must close $w after exec
3446 Returns the path name of the current working directory.
3450 +*rand* '?min? ?max?'+
3452 Returns a random integer between +'min'+ (defaults to 0) and +'max'+
3453 (defaults to the maximum integer).
3455 If only one argument is given, it is interpreted as +'max'+.
3459 +*range* '?start? end ?step?'+
3461 Returns a list of integers starting at +'start'+ (defaults to 0)
3462 and ranging up to but not including +'end'+ in steps of +'step'+ defaults to 1).
3475 +*read* ?*-nonewline*? 'fileId'+
3477 +'fileId' *read* ?*-nonewline*?+
3479 +*read* 'fileId numBytes'+
3481 +'fileId' *read* 'numBytes'+
3484 In the first form, all of the remaining bytes are read from the file
3485 given by +'fileId'+; they are returned as the result of the command.
3486 If the +-nonewline+ switch is specified then the last
3487 character of the file is discarded if it is a newline.
3489 In the second form, the extra argument specifies how many bytes to read;
3490 exactly this many bytes will be read and returned, unless there are fewer than
3491 +'numBytes'+ bytes left in the file; in this case, all the remaining
3494 +'fileId'+ must be +stdin+ or the return value from a previous call
3495 to `open`; it must refer to a file that was opened for reading.
3499 +*regexp ?-nocase? ?-line? ?-indices? ?-start* 'offset'? *?-all? ?-inline? ?--?* 'exp string ?matchVar? ?subMatchVar subMatchVar \...?'+
3501 Determines whether the regular expression +'exp'+ matches part or
3502 all of +'string'+ and returns 1 if it does, 0 if it doesn't.
3504 See REGULAR EXPRESSIONS above for complete information on the
3505 syntax of +'exp'+ and how it is matched against +'string'+.
3507 If additional arguments are specified after +'string'+ then they
3508 are treated as the names of variables to use to return
3509 information about which part(s) of +'string'+ matched +'exp'+.
3510 +'matchVar'+ will be set to the range of +'string'+ that
3511 matched all of +'exp'+. The first +'subMatchVar'+ will contain
3512 the characters in +'string'+ that matched the leftmost parenthesized
3513 subexpression within +'exp'+, the next +'subMatchVar'+ will
3514 contain the characters that matched the next parenthesized
3515 subexpression to the right in +'exp'+, and so on.
3517 Normally, +'matchVar'+ and the each +'subMatchVar'+ are set to hold the
3518 matching characters from `string`, however see +-indices+ and
3521 If there are more values for +'subMatchVar'+ than parenthesized subexpressions
3522 within +'exp'+, or if a particular subexpression in +'exp'+ doesn't
3523 match the string (e.g. because it was in a portion of the expression
3524 that wasn't matched), then the corresponding +'subMatchVar'+ will be
3525 set to +"-1 -1"+ if +-indices+ has been specified or to an empty
3528 The following switches modify the behaviour of +'regexp'+
3531 Causes upper-case and lower-case characters to be treated as
3532 identical during the matching process.
3535 Use newline-sensitive matching. By default, newline
3536 is a completely ordinary character with no special meaning in
3537 either REs or strings. With this flag, +[^+ bracket expressions
3538 and +.+ never match newline, an +^+ anchor matches the null
3539 string after any newline in the string in addition to its normal
3540 function, and the +$+ anchor matches the null string before any
3541 newline in the string in addition to its normal function.
3544 Changes what is stored in the subMatchVars. Instead of
3545 storing the matching characters from string, each variable
3546 will contain a list of two decimal strings giving the indices
3547 in string of the first and last characters in the matching
3548 range of characters.
3550 +*-start* 'offset'+::
3551 Specifies a character index offset into the string at which to start
3552 matching the regular expression. If +-indices+ is
3553 specified, the indices will be indexed starting from the
3554 absolute beginning of the input string. +'offset'+ will be
3555 constrained to the bounds of the input string.
3558 Causes the regular expression to be matched as many times as possible
3559 in the string, returning the total number of matches found. If this
3560 is specified with match variables, they will contain information
3561 for the last match only.
3564 Causes the command to return, as a list, the data that would otherwise
3565 be placed in match variables. When using +-inline+, match variables
3566 may not be specified. If used with +-all+, the list will be concatenated
3567 at each iteration, such that a flat list is always returned. For
3568 each match iteration, the command will append the overall match
3569 data, plus one element for each subexpression in the regular
3573 Marks the end of switches. The argument following this one will be
3574 treated as +'exp'+ even if it starts with a +-+.
3578 +*regsub ?-nocase? ?-all? ?-line? ?-start* 'offset'? ?*--*? 'exp string subSpec ?varName?'+
3580 This command matches the regular expression +'exp'+ against
3581 +'string'+ using the rules described in REGULAR EXPRESSIONS
3584 If +'varName'+ is specified, the commands stores +'string'+ to +'varName'+
3585 with the substitutions detailed below, and returns the number of
3586 substitutions made (normally 1 unless +-all+ is specified).
3587 This is 0 if there were no matches.
3589 If +'varName'+ is not specified, the substituted string will be returned
3592 When copying +'string'+, the portion of +'string'+ that
3593 matched +'exp'+ is replaced with +'subSpec'+.
3594 If +'subSpec'+ contains a +&+ or +{backslash}0+, then it is replaced
3595 in the substitution with the portion of +'string'+ that
3598 If +'subSpec'+ contains a +{backslash}n+, where +'n'+ is a digit
3599 between 1 and 9, then it is replaced in the substitution with
3600 the portion of +'string'+ that matched the +'n'+\'-th
3601 parenthesized subexpression of +'exp'+.
3602 Additional backslashes may be used in +'subSpec'+ to prevent special
3603 interpretation of +&+ or +{backslash}0+ or +{backslash}n+ or
3606 The use of backslashes in +'subSpec'+ tends to interact badly
3607 with the Tcl parser's use of backslashes, so it's generally
3608 safest to enclose +'subSpec'+ in braces if it includes
3611 The following switches modify the behaviour of +'regsub'+
3614 Upper-case characters in +'string'+ are converted to lower-case
3615 before matching against +'exp'+; however, substitutions
3616 specified by +'subSpec'+ use the original unconverted form
3620 All ranges in +'string'+ that match +'exp'+ are found and substitution
3621 is performed for each of these ranges, rather than only the
3622 first. The +&+ and +{backslash}n+ sequences are handled for
3623 each substitution using the information from the corresponding
3627 Use newline-sensitive matching. By default, newline
3628 is a completely ordinary character with no special meaning in
3629 either REs or strings. With this flag, +[^+ bracket expressions
3630 and +.+ never match newline, an +^+ anchor matches the null
3631 string after any newline in the string in addition to its normal
3632 function, and the +$+ anchor matches the null string before any
3633 newline in the string in addition to its normal function.
3635 +*-start* 'offset'+::
3636 Specifies a character index offset into the string at which to
3637 start matching the regular expression. +'offset'+ will be
3638 constrained to the bounds of the input string.
3641 Marks the end of switches. The argument following this one will be
3642 treated as +'exp'+ even if it starts with a +-+.
3646 +*ref* 'string tag ?finalizer?'+
3648 Create a new reference containing +'string'+ of type +'tag'+.
3649 If +'finalizer'+ is specified, it is a command which will be invoked
3650 when the a garbage collection cycle runs and this reference is
3651 no longer accessible.
3653 The finalizer is invoked as:
3655 finalizer reference string
3657 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
3661 +*rename* 'oldName newName'+
3663 Rename the command that used to be called +'oldName'+ so that it
3664 is now called +'newName'+. If +'newName'+ is an empty string
3665 (e.g. {}) then +'oldName'+ is deleted. The `rename` command
3666 returns an empty string as result.
3670 +*return* ?*-code* 'code'? ?*-errorinfo* 'stacktrace'? ?*-errorcode* 'errorcode'? ?*-level* 'n'? ?'value'?+
3672 Return immediately from the current procedure (or top-level command
3673 or `source` command), with +'value'+ as the return value. If +'value'+
3674 is not specified, an empty string will be returned as result.
3676 If +-code+ is specified (as either a number or ok, error, break,
3677 continue, signal, return or exit), this code will be used instead
3678 of +JIM_OK+. This is generally useful when implementing flow of control
3681 If +-level+ is specified and greater than 1, it has the effect of delaying
3682 the new return code from +-code+. This is useful when rethrowing an error
3683 from `catch`. See the implementation of try/catch in tclcompat.tcl for
3684 an example of how this is done.
3686 Note: The following options are only used when +-code+ is JIM_ERR.
3688 If +-errorinfo+ is specified (as returned from `info stacktrace`)
3689 it is used to initialize the stacktrace.
3691 If +-errorcode+ is specified, it is used to set the global variable $::errorCode.
3695 +*scan* 'string format varName1 ?varName2 \...?'+
3697 This command parses fields from an input string in the same fashion
3698 as the C 'sscanf' procedure. +'string'+ gives the input to be parsed
3699 and +'format'+ indicates how to parse it, using '%' fields as in
3700 'sscanf'. All of the 'sscanf' options are valid; see the 'sscanf'
3701 man page for details. Each +'varName'+ gives the name of a variable;
3702 when a field is scanned from +'string'+, the result is converted back
3703 into a string and assigned to the corresponding +'varName'+. The
3704 only unusual conversion is for '%c'. For '%c' conversions a single
3705 character value is converted to a decimal string, which is then
3706 assigned to the corresponding +'varName'+; no field width may be
3707 specified for this conversion.
3711 +*seek* 'fileId offset ?origin?'+
3713 +'fileId' *seek* 'offset ?origin?'+
3715 Change the current access position for +'fileId'+.
3716 The +'offset'+ and +'origin'+ arguments specify the position at
3717 which the next read or write will occur for +'fileId'+.
3718 +'offset'+ must be a number (which may be negative) and +'origin'+
3719 must be one of the following:
3722 The new access position will be +'offset'+ bytes from the start
3726 The new access position will be +'offset'+ bytes from the current
3727 access position; a negative +'offset'+ moves the access position
3728 backwards in the file.
3731 The new access position will be +'offset'+ bytes from the end of
3732 the file. A negative +'offset'+ places the access position before
3733 the end-of-file, and a positive +'offset'+ places the access position
3734 after the end-of-file.
3736 The +'origin'+ argument defaults to +start+.
3738 +'fileId'+ must have been the return value from a previous call to
3739 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
3740 of the standard I/O channels.
3742 This command returns an empty string.
3746 +*set* 'varName ?value?'+
3748 Returns the value of variable +'varName'+.
3750 If +'value'+ is specified, then set the value of +'varName'+ to +'value'+,
3751 creating a new variable if one doesn't already exist, and return
3754 If +'varName'+ contains an open parenthesis and ends with a
3755 close parenthesis, then it refers to an array element: the characters
3756 before the open parenthesis are the name of the array, and the characters
3757 between the parentheses are the index within the array.
3758 Otherwise +'varName'+ refers to a scalar variable.
3760 If no procedure is active, then +'varName'+ refers to a global
3763 If a procedure is active, then +'varName'+ refers to a parameter
3764 or local variable of the procedure, unless the +'global'+ command
3765 has been invoked to declare +'varName'+ to be global.
3767 The +::+ prefix may also be used to explicitly reference a variable
3768 in the global scope.
3772 +*setref* 'reference string'+
3774 Store a new string in +'reference'+, replacing the existing string.
3775 The reference must be a valid reference create with the `ref`
3778 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
3782 Command for signal handling.
3784 See `kill` for the different forms which may be used to specify signals.
3786 Commands which return a list of signal names do so using the canonical form:
3789 +*signal handle* ?'signals \...'?+::
3790 If no signals are given, returns a list of all signals which are currently
3792 If signals are specified, these are added to the list of signals currently
3795 +*signal ignore* ?'signals \...'?+::
3796 If no signals are given, returns a lists all signals which are currently
3798 If signals are specified, these are added to the list of signals
3799 currently being ignored. These signals are still delivered, but
3800 are not considered by `catch -signal` or `try -signal`. Use
3801 `signal check` to determine which signals have occurred but
3804 +*signal block* ?'signals \...'?+::
3805 If no signals are given, returns a lists all signals which are currently
3807 If signals are specified, these are added to the list of signals
3808 currently being blocked. These signals are not delivered to the process.
3809 This can be useful for signals such as +SIGPIPE+, especially in conjunction
3810 with `exec` as child processes inherit the parent's signal disposition.
3812 +*signal default* ?'signals \...'?+::
3813 If no signals are given, returns a lists all signals which currently have
3814 the default behaviour.
3815 If signals are specified, these are added to the list of signals which have
3816 the default behaviour.
3818 +*signal check ?-clear?* ?'signals \...'?+::
3819 Returns a list of signals which have been delivered to the process
3820 but are 'ignored'. If signals are specified, only that set of signals will
3821 be checked, otherwise all signals will be checked.
3822 If +-clear+ is specified, any signals returned are removed and will not be
3823 returned by subsequent calls to `signal check` unless delivered again.
3825 +*signal throw* ?'signal'?+::
3826 Raises the given signal, which defaults to +SIGINT+ if not specified.
3827 The behaviour is identical to:
3831 Note that `signal handle` and `signal ignore` represent two forms of signal
3832 handling. `signal handle` is used in conjunction with `catch -signal` or `try -signal`
3833 to immediately abort execution when the signal is delivered. Alternatively, `signal ignore`
3834 is used in conjunction with `signal check` to handle signal synchronously. Consider the
3837 Prevent a processing from taking too long
3839 signal handle SIGALRM
3842 .. possibly long running process ..
3845 puts stderr "Process took too long"
3848 Handle SIGHUP to reconfigure:
3850 signal ignore SIGHUP
3852 ... handle configuration/reconfiguration ...
3853 while {[signal check -clear SIGHUP] eq ""} {
3854 ... do processing ..
3856 # Received SIGHUP, so reconfigure
3859 Note: signal handling is currently not supported in child interpreters.
3860 In these interpreters, the signal command does not exist.
3866 Pauses for the given number of seconds, which may be a floating
3867 point value less than one to sleep for less than a second, or an
3868 integer to sleep for one or more seconds.
3872 +*source* 'fileName'+
3874 Read file +'fileName'+ and pass the contents to the Tcl interpreter
3875 as a sequence of commands to execute in the normal fashion. The return
3876 value of `source` is the return value of the last command executed
3877 from the file. If an error occurs in executing the contents of the
3878 file, then the `source` command will return that error.
3880 If a `return` command is invoked from within the file, the remainder of
3881 the file will be skipped and the `source` command will return
3882 normally with the result from the `return` command.
3886 +*split* 'string ?splitChars?'+
3888 Returns a list created by splitting +'string'+ at each character
3889 that is in the +'splitChars'+ argument.
3891 Each element of the result list will consist of the
3892 characters from +'string'+ between instances of the
3893 characters in +'splitChars'+.
3895 Empty list elements will be generated if +'string'+ contains
3896 adjacent characters in +'splitChars'+, or if the first or last
3897 character of +'string'+ is in +'splitChars'+.
3899 If +'splitChars'+ is an empty string then each character of
3900 +'string'+ becomes a separate element of the result list.
3902 +'splitChars'+ defaults to the standard white-space characters.
3905 split "comp.unix.misc" .
3907 returns +'"comp unix misc"'+ and
3909 split "Hello world" {}
3911 returns +'"H e l l o { } w o r l d"'+.
3916 +*stackdump* 'stacktrace'+
3918 Creates a human readable representation of a stack trace.
3925 Returns a live stack trace as a list of +proc file line proc file line \...+.
3926 Iteratively uses `info frame` to create the stack trace. This stack trace is in the
3927 same form as produced by `catch` and `info stacktrace`
3929 See also `stackdump`.
3934 +*string* 'option arg ?arg \...?'+
3936 Perform one of several string operations, depending on +'option'+.
3937 The legal options (which may be abbreviated) are:
3939 +*string bytelength* 'string'+::
3940 Returns the length of the string in bytes. This will return
3941 the same value as `string length` if UTF-8 support is not enabled,
3942 or if the string is composed entirely of ASCII characters.
3943 See UTF-8 AND UNICODE.
3945 +*string byterange* 'string first last'+::
3946 Like `string range` except works on bytes rather than characters.
3947 These commands are identical if UTF-8 support is not enabled.
3949 +*string cat* '?string1 string2 \...?'+::
3950 Concatenates the given strings into a single string.
3952 +*string compare ?-nocase?* ?*-length* 'len? string1 string2'+::
3953 Perform a character-by-character comparison of strings +'string1'+ and
3954 +'string2'+ in the same way as the C 'strcmp' procedure. Return
3955 -1, 0, or 1, depending on whether +'string1'+ is lexicographically
3956 less than, equal to, or greater than +'string2'+. If +-length+
3957 is specified, then only the first +'len'+ characters are used
3958 in the comparison. If +'len'+ is negative, it is ignored.
3959 Performs a case-insensitive comparison if +-nocase+ is specified.
3961 +*string equal ?-nocase?* '?*-length* len?' 'string1 string2'+::
3962 Returns 1 if the strings are equal, or 0 otherwise. If +-length+
3963 is specified, then only the first +'len'+ characters are used
3964 in the comparison. If +'len'+ is negative, it is ignored.
3965 Performs a case-insensitive comparison if +-nocase+ is specified.
3967 +*string first* 'string1 string2 ?firstIndex?'+::
3968 Search +'string2'+ for a sequence of characters that exactly match
3969 the characters in +'string1'+. If found, return the index of the
3970 first character in the first such match within +'string2'+. If not
3971 found, return -1. If +'firstIndex'+ is specified, matching will start
3972 from +'firstIndex'+ of +'string1'+.
3974 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'firstIndex'+.
3976 +*string index* 'string charIndex'+::
3977 Returns the +'charIndex'+'th character of the +'string'+
3978 argument. A +'charIndex'+ of 0 corresponds to the first
3979 character of the string.
3980 If +'charIndex'+ is less than 0 or greater than
3981 or equal to the length of the string then an empty string is
3984 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'charIndex'+.
3986 +*string is* 'class' ?*-strict*? 'string'+::
3987 Returns 1 if +'string'+ is a valid member of the specified character
3988 class, otherwise returns 0. If +-strict+ is specified, then an
3989 empty string returns 0, otherwise an empty string will return 1
3990 on any class. The following character classes are recognized
3991 (the class name can be abbreviated):
3993 +alnum+;; Any alphabet or digit character.
3994 +alpha+;; Any alphabet character.
3995 +ascii+;; Any character with a value less than 128 (those that are in the 7-bit ascii range).
3996 +boolean+;; Any of the valid string formats for a boolean value in Tcl (0, false, no, off, 1, true, yes, on)
3997 +control+;; Any control character.
3998 +digit+;; Any digit character.
3999 +double+;; Any of the valid forms for a double in Tcl, with optional surrounding whitespace.
4000 In case of under/overflow in the value, 0 is returned.
4001 +graph+;; Any printing character, except space.
4002 +integer+;; Any of the valid string formats for an integer value in Tcl, with optional surrounding whitespace.
4003 +lower+;; Any lower case alphabet character.
4004 +print+;; Any printing character, including space.
4005 +punct+;; Any punctuation character.
4006 +space+;; Any space character.
4007 +upper+;; Any upper case alphabet character.
4008 +xdigit+;; Any hexadecimal digit character ([0-9A-Fa-f]).
4010 Note that string classification does +'not'+ respect UTF-8. See UTF-8 AND UNICODE
4012 Note that only +'lowercase'+ boolean values are recognized (Tcl accepts any case).
4014 +*string last* 'string1 string2 ?lastIndex?'+::
4015 Search +'string2'+ for a sequence of characters that exactly match
4016 the characters in +'string1'+. If found, return the index of the
4017 first character in the last such match within +'string2'+. If there
4018 is no match, then return -1. If +'lastIndex'+ is specified, only characters
4019 up to +'lastIndex'+ of +'string2'+ will be considered in the match.
4021 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'lastIndex'+.
4023 +*string length* 'string'+::
4024 Returns a decimal string giving the number of characters in +'string'+.
4025 If UTF-8 support is enabled, this may be different than the number of bytes.
4026 See UTF-8 AND UNICODE
4028 +*string map ?-nocase?* 'mapping string'+::
4029 Replaces substrings in +'string'+ based on the key-value pairs in
4030 +'mapping'+, which is a list of +key value key value \...+ as in the form
4031 returned by `array get`. Each instance of a key in the string will be
4032 replaced with its corresponding value. If +-nocase+ is specified, then
4033 matching is done without regard to case differences. Both key and value may
4034 be multiple characters. Replacement is done in an ordered manner, so the
4035 key appearing first in the list will be checked first, and so on. +'string'+ is
4036 only iterated over once, so earlier key replacements will have no affect for
4037 later key matches. For example,
4039 string map {abc 1 ab 2 a 3 1 0} 1abcaababcabababc
4042 will return the string +01321221+.
4044 Note that if an earlier key is a prefix of a later one, it will completely mask the later
4045 one. So if the previous example is reordered like this,
4047 string map {1 0 ab 2 a 3 abc 1} 1abcaababcabababc
4050 it will return the string +02c322c222c+.
4052 +*string match ?-nocase?* 'pattern string'+::
4053 See if +'pattern'+ matches +'string'+; return 1 if it does, 0
4054 if it doesn't. Matching is done in a fashion similar to that
4055 used by the C-shell. For the two strings to match, their contents
4056 must be identical except that the following special sequences
4057 may appear in +'pattern'+:
4060 Matches any sequence of characters in +'string'+,
4061 including a null string.
4064 Matches any single character in +'string'+.
4067 Matches any character in the set given by +'chars'+.
4068 If a sequence of the form +'x-y'+ appears in +'chars'+,
4069 then any character between +'x'+ and +'y'+, inclusive,
4073 Matches the single character +'x'+. This provides a way of
4074 avoiding the special interpretation of the characters +{backslash}*?[]+
4077 Performs a case-insensitive comparison if +-nocase+ is specified.
4079 +*string range* 'string first last'+::
4080 Returns a range of consecutive characters from +'string'+, starting
4081 with the character whose index is +'first'+ and ending with the
4082 character whose index is +'last'+. An index of 0 refers to the
4083 first character of the string.
4085 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
4087 If +'first'+ is less than zero then it is treated as if it were zero, and
4088 if +'last'+ is greater than or equal to the length of the string then
4089 it is treated as if it were +end+. If +'first'+ is greater than
4090 +'last'+ then an empty string is returned.
4092 +*string repeat* 'string count'+::
4093 Returns a new string consisting of +'string'+ repeated +'count'+ times.
4095 +*string replace* 'string first last ?newstring?'+::
4096 Removes a range of consecutive characters from +'string'+, starting
4097 with the character whose index is +'first'+ and ending with the
4098 character whose index is +'last'+. If +'newstring'+ is specified,
4099 then it is placed in the removed character range. If +'first'+ is
4100 less than zero then it is treated as if it were zero, and if +'last'+
4101 is greater than or equal to the length of the string then it is
4102 treated as if it were +end+. If +'first'+ is greater than +'last'+
4103 or the length of the initial string, or +'last'+ is less than 0,
4104 then the initial string is returned untouched.
4106 +*string reverse* 'string'+::
4107 Returns a string that is the same length as +'string'+ but
4108 with its characters in the reverse order.
4110 +*string tolower* 'string'+::
4111 Returns a value equal to +'string'+ except that all upper case
4112 letters have been converted to lower case.
4114 +*string totitle* 'string'+::
4115 Returns a value equal to +'string'+ except that the first character
4116 is converted to title case (or upper case if there is no UTF-8 titlecase variant)
4117 and all remaining characters have been converted to lower case.
4119 +*string toupper* 'string'+::
4120 Returns a value equal to +'string'+ except that all lower case
4121 letters have been converted to upper case.
4123 +*string trim* 'string ?chars?'+::
4124 Returns a value equal to +'string'+ except that any leading
4125 or trailing characters from the set given by +'chars'+ are
4127 If +'chars'+ is not specified then white space is removed
4128 (spaces, tabs, newlines, and carriage returns).
4130 +*string trimleft* 'string ?chars?'+::
4131 Returns a value equal to +'string'+ except that any
4132 leading characters from the set given by +'chars'+ are
4134 If +'chars'+ is not specified then white space is removed
4135 (spaces, tabs, newlines, and carriage returns).
4137 +*string trimright* 'string ?chars?'+::
4138 Returns a value equal to +'string'+ except that any
4139 trailing characters from the set given by +'chars'+ are
4141 If +'chars'+ is not specified then white space is removed
4142 (spaces, tabs, newlines, and carriage returns).
4143 Null characters are always removed.
4147 +*subst ?-nobackslashes? ?-nocommands? ?-novariables?* 'string'+
4149 This command performs variable substitutions, command substitutions,
4150 and backslash substitutions on its string argument and returns the
4151 fully-substituted result. The substitutions are performed in exactly
4152 the same way as for Tcl commands. As a result, the string argument
4153 is actually substituted twice, once by the Tcl parser in the usual
4154 fashion for Tcl commands, and again by the subst command.
4156 If any of the +-nobackslashes+, +-nocommands+, or +-novariables+ are
4157 specified, then the corresponding substitutions are not performed.
4158 For example, if +-nocommands+ is specified, no command substitution
4159 is performed: open and close brackets are treated as ordinary
4160 characters with no special interpretation.
4162 *Note*: when it performs its substitutions, subst does not give any
4163 special treatment to double quotes or curly braces. For example,
4164 the following script returns +xyz \{44\}+, not +xyz \{$a\}+.
4172 +*switch* '?options? string pattern body ?pattern body \...?'+
4174 +*switch* '?options? string {pattern body ?pattern body \...?}'+
4176 The `switch` command matches its string argument against each of
4177 the pattern arguments in order. As soon as it finds a pattern that
4178 matches string it evaluates the following body and returns the
4179 result of that evaluation. If the last pattern argument is default
4180 then it matches anything. If no pattern argument matches string and
4181 no default is given, then the `switch` command returns an empty string.
4182 If the initial arguments to switch start with - then they are treated
4183 as options. The following options are currently supported:
4186 Use exact matching when comparing string to a
4187 pattern. This is the default.
4190 When matching string to the patterns, use glob-style
4191 matching (i.e. the same as implemented by the string
4195 When matching string to the patterns, use regular
4196 expression matching (i.e. the same as implemented
4197 by the regexp command).
4199 +-command 'commandname'+::
4200 When matching string to the patterns, use the given command, which
4201 must be a single word. The command is invoked as
4202 'commandname pattern string', or 'commandname -nocase pattern string'
4203 and must return 1 if matched, or 0 if not.
4206 Marks the end of options. The argument following
4207 this one will be treated as string even if it starts
4210 Two syntaxes are provided for the pattern and body arguments. The
4211 first uses a separate argument for each of the patterns and commands;
4212 this form is convenient if substitutions are desired on some of the
4213 patterns or commands. The second form places all of the patterns
4214 and commands together into a single argument; the argument must
4215 have proper list structure, with the elements of the list being the
4216 patterns and commands. The second form makes it easy to construct
4217 multi-line `switch` commands, since the braces around the whole list
4218 make it unnecessary to include a backslash at the end of each line.
4219 Since the pattern arguments are in braces in the second form, no
4220 command or variable substitutions are performed on them; this makes
4221 the behaviour of the second form different than the first form in
4224 If a body is specified as +-+ it means that the body for the next
4225 pattern should also be used as the body for this pattern (if the
4226 next pattern also has a body of +-+ then the body after that is
4227 used, and so on). This feature makes it possible to share a single
4228 body among several patterns.
4230 Below are some examples of `switch` commands:
4232 switch abc a - b {format 1} abc {format 2} default {format 3}
4236 switch -regexp aaab {
4256 +*tailcall* 'cmd ?arg\...?'+
4258 The `tailcall` command provides an optimised way of invoking a command whilst replacing
4259 the current call frame. This is similar to 'exec' in Bourne Shell.
4261 The following are identical except the first immediately replaces the current call frame.
4265 return [uplevel 1 [list a b c]]
4267 `tailcall` is useful as a dispatch mechanism:
4270 tailcall sub_$cmd {*}$args
4281 Returns a decimal string giving the current access position in
4284 +'fileId'+ must have been the return value from a previous call to
4285 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
4286 of the standard I/O channels.
4290 +*throw* 'code ?msg?'+
4292 This command throws an exception (return) code along with an optional message.
4293 This command is mostly for convenient usage with `try`.
4295 The command +throw break+ is equivalent to +break+.
4296 The command +throw 20 message+ can be caught with an +on 20 \...+ clause to `try`.
4300 +*time* 'command ?count?'+
4302 This command will call the Tcl interpreter +'count'+
4303 times to execute +'command'+ (or once if +'count'+ isn't
4304 specified). It will then return a string of the form
4306 503 microseconds per iteration
4308 which indicates the average amount of time required per iteration,
4311 Time is measured in elapsed time, not CPU time.
4315 +*try* '?catchopts? tryscript' ?*on* 'returncodes {?resultvar? ?optsvar?} handlerscript \...'? ?*finally* 'finalscript'?+
4317 The `try` command is provided as a convenience for exception handling.
4319 This interpeter first evaluates +'tryscript'+ under the effect of the catch
4320 options +'catchopts'+ (e.g. +-signal -noexit --+, see `catch`).
4322 It then evaluates the script for the first matching 'on' handler
4323 (there many be zero or more) based on the return code from the `try`
4324 section. For example a normal +JIM_ERR+ error will be matched by
4325 an 'on error' handler.
4327 Finally, any +'finalscript'+ is evaluated.
4329 The result of this command is the result of +'tryscript'+, except in the
4330 case where an exception occurs in a matching 'on' handler script or the 'finally' script,
4331 in which case the result is this new exception.
4333 The specified +'returncodes'+ is a list of return codes either as names ('ok', 'error', 'break', etc.)
4336 If +'resultvar'+ and +'optsvar'+ are specified, they are set as for `catch` before evaluating
4337 the matching handler.
4344 } on {continue break} {} {
4345 error "Unexpected break/continue"
4346 } on error {msg opts} {
4347 puts "Dealing with error"
4348 return {*}$opts $msg
4350 puts "Got signal: $sig"
4355 If break, continue or error are raised, they are dealt with by the matching
4358 In any case, the file will be closed via the 'finally' clause.
4360 See also `throw`, `catch`, `return`, `error`.
4364 +*unknown* 'cmdName ?arg arg ...?'+
4366 This command doesn't actually exist as part of Tcl, but Tcl will
4367 invoke it if it does exist.
4369 If the Tcl interpreter encounters a command name for which there
4370 is not a defined command, then Tcl checks for the existence of
4371 a command named `unknown`.
4373 If there is no such command, then the interpreter returns an
4376 If the `unknown` command exists, then it is invoked with
4377 arguments consisting of the fully-substituted name and arguments
4378 for the original non-existent command.
4380 The `unknown` command typically does things like searching
4381 through library directories for a command procedure with the name
4382 +'cmdName'+, or expanding abbreviated command names to full-length,
4383 or automatically executing unknown commands as UNIX sub-processes.
4385 In some cases (such as expanding abbreviations) `unknown` will
4386 change the original command slightly and then (re-)execute it.
4387 The result of the `unknown` command is used as the result for
4388 the original non-existent command.
4392 +*unset ?-nocomplain? ?--?* '?name name ...?'+
4395 Each +'name'+ is a variable name, specified in any of the
4396 ways acceptable to the `set` command.
4398 If a +'name'+ refers to an element of an array, then that
4399 element is removed without affecting the rest of the array.
4401 If a +'name'+ consists of an array name with no parenthesized
4402 index, then the entire array is deleted.
4404 The `unset` command returns an empty string as result.
4406 An error occurs if any of the variables doesn't exist, unless '-nocomplain'
4407 is specified. The '--' argument may be specified to stop option processing
4408 in case the variable name may be '-nocomplain'.
4412 +*upcall* 'command ?args ...?'+
4414 May be used from within a proc defined as `local` `proc` in order to call
4415 the previous, hidden version of the same command.
4417 If there is no previous definition of the command, an error is returned.
4421 +*uplevel* '?level? command ?command ...?'+
4423 All of the +'command'+ arguments are concatenated as if they had
4424 been passed to `concat`; the result is then evaluated in the
4425 variable context indicated by +'level'+. `uplevel` returns
4426 the result of that evaluation. If +'level'+ is an integer, then
4427 it gives a distance (up the procedure calling stack) to move before
4428 executing the command. If +'level'+ consists of +\#+ followed by
4429 a number then the number gives an absolute level number. If +'level'+
4430 is omitted then it defaults to +1+. +'level'+ cannot be
4431 defaulted if the first +'command'+ argument starts with a digit or +#+.
4433 For example, suppose that procedure 'a' was invoked
4434 from top-level, and that it called 'b', and that 'b' called 'c'.
4435 Suppose that 'c' invokes the `uplevel` command. If +'level'+
4436 is +1+ or +#2+ or omitted, then the command will be executed
4437 in the variable context of 'b'. If +'level'+ is +2+ or +#1+
4438 then the command will be executed in the variable context of 'a'.
4440 If +'level'+ is '3' or +#0+ then the command will be executed
4441 at top-level (only global variables will be visible).
4442 The `uplevel` command causes the invoking procedure to disappear
4443 from the procedure calling stack while the command is being executed.
4444 In the above example, suppose 'c' invokes the command
4446 uplevel 1 {set x 43; d}
4448 where 'd' is another Tcl procedure. The `set` command will
4449 modify the variable 'x' in 'b's context, and 'd' will execute
4450 at level 3, as if called from 'b'. If it in turn executes
4455 then the `set` command will modify the same variable 'x' in 'b's
4456 context: the procedure 'c' does not appear to be on the call stack
4457 when 'd' is executing. The command `info level` may
4458 be used to obtain the level of the current procedure.
4460 `uplevel` makes it possible to implement new control
4461 constructs as Tcl procedures (for example, `uplevel` could
4462 be used to implement the `while` construct as a Tcl procedure).
4466 +*upvar* '?level? otherVar myVar ?otherVar myVar ...?'+
4468 This command arranges for one or more local variables in the current
4469 procedure to refer to variables in an enclosing procedure call or
4470 to global variables.
4472 +'level'+ may have any of the forms permitted for the `uplevel`
4473 command, and may be omitted if the first letter of the first +'otherVar'+
4474 isn't +#+ or a digit (it defaults to '1').
4476 For each +'otherVar'+ argument, `upvar` makes the variable
4477 by that name in the procedure frame given by +'level'+ (or at
4478 global level, if +'level'+ is +#0+) accessible
4479 in the current procedure by the name given in the corresponding
4482 The variable named by +'otherVar'+ need not exist at the time of the
4483 call; it will be created the first time +'myVar'+ is referenced, just like
4484 an ordinary variable.
4486 `upvar` may only be invoked from within procedures.
4488 `upvar` returns an empty string.
4490 The `upvar` command simplifies the implementation of call-by-name
4491 procedure calling and also makes it easier to build new control constructs
4493 For example, consider the following procedure:
4500 'add2' is invoked with an argument giving the name of a variable,
4501 and it adds two to the value of that variable.
4502 Although 'add2' could have been implemented using `uplevel`
4503 instead of `upvar`, `upvar` makes it simpler for 'add2'
4504 to access the variable in the caller's procedure frame.
4510 +*wait -nohang* 'pid'+
4512 With no arguments, cleans up any processes started by `exec ... &` that have completed
4513 (reaps zombie processes).
4515 With one or two arguments, waits for a process by id, either returned by `exec ... &`
4516 or by `os.fork` (if supported).
4518 Waits for the process to complete, unless +-nohang+ is specified, in which case returns
4519 immediately if the process is still running.
4521 Returns a list of 3 elements.
4523 +{NONE x x}+ if the process does not exist or has already been waited for, or
4524 if -nohang is specified, and the process is still alive.
4526 +{CHILDSTATUS <pid> <exit-status>}+ if the process exited normally.
4528 +{CHILDKILLED <pid> <signal>}+ if the process terminated on a signal.
4530 +{CHILDSUSP <pid> none}+ if the process terminated for some other reason.
4532 Note that on platforms supporting waitpid(2), +pid+ can also be given special values such
4533 as 0 or -1. See waitpid(2) for more detail.
4537 +*while* 'test body'+
4539 The +'while'+ command evaluates +'test'+ as an expression
4540 (in the same way that `expr` evaluates its argument).
4541 The value of the expression must be numeric; if it is non-zero
4542 then +'body'+ is executed by passing it to the Tcl interpreter.
4544 Once +'body'+ has been executed then +'test'+ is evaluated
4545 again, and the process repeats until eventually +'test'+
4546 evaluates to a zero numeric value. `continue`
4547 commands may be executed inside +'body'+ to terminate the current
4548 iteration of the loop, and `break`
4549 commands may be executed inside +'body'+ to cause immediate
4550 termination of the `while` command.
4552 The `while` command always returns an empty string.
4557 The following extensions may or may not be available depending upon
4558 what options were selected when Jim Tcl was built.
4562 posix: os.fork, os.gethostname, os.getids, os.uptime
4563 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4565 Invokes 'fork(2)' and returns the result.
4567 +*os.gethostname*+::
4568 Invokes 'gethostname(3)' and returns the result.
4571 Returns the various user/group ids for the current process.
4574 uid 1000 euid 1000 gid 100 egid 100
4577 Returns the number of seconds since system boot. See description of 'uptime' in 'sysinfo(2)'.
4579 ANSI I/O (aio) and EVENTLOOP API
4580 --------------------------------
4581 Jim provides an alternative object-based API for I/O.
4583 See `open` and `socket` for commands which return an I/O handle.
4587 +$handle *accept* ?addrvar?+::
4588 Server socket only: Accept a connection and return stream.
4589 If +'addrvar'+ is specified, the address of the connected client is stored
4590 in the named variable in the form 'addr:port' for IP sockets or 'path' for Unix domain sockets.
4591 See `socket` for details.
4593 +$handle *buffering none|line|full*+::
4594 Sets the buffering mode of the stream.
4596 +$handle *close ?r(ead)|w(rite)|-nodelete?*+::
4598 The +'read'+ and +'write'+ arguments perform a "half-close" on a socket. See the 'shutdown(2)' man page.
4599 The +'-nodelete'+ option is applicable only for Unix domain sockets. It closes the socket
4600 but does not delete the bound path (e.g. after `os.fork`).
4603 +$handle *copyto* 'tofd ?size?'+::
4604 Copy bytes to the file descriptor +'tofd'+. If +'size'+ is specified, at most
4605 that many bytes will be copied. Otherwise copying continues until the end
4606 of the input file. Returns the number of bytes actually copied.
4609 Returns 1 if stream is at eof
4611 +$handle *filename*+::
4612 Returns the original filename associated with the handle.
4613 Handles returned by `socket` give the socket type instead of a filename.
4618 +$handle *gets* '?var?'+::
4619 Read one line and return it or store it in the var
4621 +$handle *isatty*+::
4622 Returns 1 if the stream is a tty device.
4624 +$handle *lock ?-wait?*+::
4625 Apply a POSIX lock to the open file associated with the handle using
4626 'fcntl(F_SETLK)', or 'fcntl(F_SETLKW)' to wait for the lock to be available if +'-wait'+
4628 The handle must be open for write access.
4629 Returns 1 if the lock was successfully obtained, 0 otherwise.
4630 An error occurs if the handle is not suitable for locking (e.g.
4631 if it is not open for write)
4633 +$handle *ndelay ?0|1?*+::
4634 Set O_NDELAY (if arg). Returns current/new setting.
4635 Note that in general ANSI I/O interacts badly with non-blocking I/O.
4638 +$handle *peername*+::
4639 Returns the remote address or path of the connected socket. See 'getpeername(2)'.
4641 +$handle *puts ?-nonewline?* 'str'+::
4642 Write the string, with newline unless -nonewline
4644 +$handle *read ?-nonewline?* '?len?'+::
4645 Read and return bytes from the stream. To eof if no len.
4647 +$handle *recvfrom* 'maxlen ?addrvar?'+::
4648 Receives a message from the handle via recvfrom(2) and returns it.
4649 At most +'maxlen'+ bytes are read. If +'addrvar'+ is specified, the sending address
4650 of the message is stored in the named variable in the form 'addr:port' for IP sockets
4651 or 'path' for Unix domain sockets. See `socket` for details.
4653 +$handle *seek* 'offset' *?start|current|end?*+::
4654 Seeks in the stream (default 'current')
4656 +$handle *sendto* 'str ?address'+::
4657 Sends the string, +'str'+, to the given address (host:port or path) via the socket using 'sendto(2)'.
4658 This is intended for udp/dgram sockets and may give an error or behave in unintended
4659 ways for other handle types.
4660 Returns the number of bytes written.
4662 +$handle *sockname*+::
4663 Returns the bound address or path of the socket. See 'getsockname(2)'.
4665 +$handle *sockopt* '?name value?'+::
4666 With no arguments, returns a dictionary of socket options currently set for the handle
4667 (will be empty for a non-socket). With +'name'+ and +'value'+, sets the socket option
4668 to the given value. Currently supports the following boolean socket options:
4669 +broadcast, debug, keepalive, nosigpipe, oobinline, tcp_nodelay+, and the following
4670 integer socket options: +sndbuf, rcvbuf+
4673 Flush the stream, then 'fsync(2)' to commit any changes to storage.
4674 Only available on platforms that support 'fsync(2)'.
4677 Returns the current seek position
4679 +$handle *tty* ?settings?+::
4680 If no arguments are given, returns a dictionary containing the tty settings for the stream.
4681 If arguments are given, they must either be a dictionary, or +setting value \...+
4682 Abbrevations are supported for both settings and values, so the following is acceptable:
4683 +$f tty parity e input c out raw+.
4684 Only available on platforms that support 'termios(3)'. Supported settings are:
4687 Baud rate. e.g. 115200
4695 +*parity even|odd|none*+;;
4698 +*handshake xonxoff|rtscts|none*+;;
4701 +*input raw|cooked*+;;
4702 Input character processing. In raw mode, the usual key sequences such as ^C do
4703 not generate signals.
4705 +*output raw|cooked*+;;
4706 Output character processing. Typically CR -> CRNL is disabled in raw mode.
4708 +*vmin* 'numchars'+;;
4709 Minimum number of characters to read.
4712 Timeout for noncanonical read (units of 0.1 seconds)
4714 +$handle *ssl* ?*-server* 'cert priv'?+::
4715 Upgrades the stream to a SSL/TLS session and returns the handle.
4717 +$handle *unlock*+::
4718 Release a POSIX lock previously acquired by `aio lock`.
4720 +$handle *verify*+::
4721 Verifies the certificate of a SSL/TLS stream peer
4723 +*load_ssl_certs* 'dir'+::
4724 Loads SSL/TLS CA certificates for use during verification
4728 +*fconfigure* 'handle' *?-blocking 0|1? ?-buffering noneline|full? ?-translation* 'mode'?+::
4729 For compatibility with Tcl, a limited form of the `fconfigure`
4730 command is supported.
4731 * `fconfigure ... -blocking` maps to `aio ndelay`
4732 * `fconfigure ... -buffering` maps to `aio buffering`
4733 * `fconfigure ... -translation` is accepted but ignored
4736 eventloop: after, vwait, update
4737 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4739 The following commands allow a script to be invoked when the given condition occurs.
4740 If no script is given, returns the current script. If the given script is the empty, the
4743 +$handle *readable* '?readable-script?'+::
4744 Sets or returns the script for when the socket is readable.
4746 +$handle *writable* '?writable-script?'+::
4747 Sets or returns the script for when the socket is writable.
4749 +$handle *onexception* '?exception-script?'+::
4750 Sets or returns the script for when oob data received.
4752 For compatibility with 'Tcl', these may be prefixed with `fileevent`. e.g.
4755 +fileevent $handle *readable* '\...'+
4757 Time-based execution is also available via the eventloop API.
4760 Sleeps for the given number of milliseconds. No events are
4761 processed during this time.
4763 +*after* 'ms'|*idle* 'script ?script \...?'+::
4764 The scripts are concatenated and executed after the given
4765 number of milliseconds have elapsed. If 'idle' is specified,
4766 the script will run the next time the event loop is processed
4767 with `vwait` or `update`. The script is only run once and
4768 then removed. Returns an event id.
4770 +*after cancel* 'id|command'+::
4771 Cancels an `after` event with the given event id or matching
4772 command (script). Returns the number of milliseconds
4773 remaining until the event would have fired. Returns the
4774 empty string if no matching event is found.
4776 +*after info* '?id?'+::
4777 If +'id'+ is not given, returns a list of current `after`
4778 events. If +'id'+ is given, returns a list containing the
4779 associated script and either 'timer' or 'idle' to indicated
4780 the type of the event. An error occurs if +'id'+ does not
4783 +*vwait* 'variable'+::
4784 A call to `vwait` enters the eventloop. `vwait` processes
4785 events until the named (global) variable changes or all
4786 event handlers are removed. The variable need not exist
4787 beforehand. If there are no event handlers defined, `vwait`
4788 returns immediately.
4790 +*update ?idletasks?*+::
4791 A call to `update` enters the eventloop to process expired events, but
4792 no new events. If 'idletasks' is specified, only expired time events are handled,
4794 Returns once handlers have been run for all expired events.
4796 Scripts are executed at the global scope. If an error occurs during a handler script,
4797 an attempt is made to call (the user-defined command) `bgerror` with the details of the error.
4798 If the `bgerror` command does not exist, the error message details are printed to stderr instead.
4800 If a file event handler script generates an error, the handler is automatically removed
4801 to prevent infinite errors. (A time event handler is always removed after execution).
4804 Called when an event handler script generates an error. Note that the normal command resolution
4805 rules are used for bgerror. First the name is resolved in the current namespace, then in the
4810 Various socket types may be created.
4812 +*socket unix* 'path'+::
4813 A unix domain socket client connected to 'path'
4815 +*socket unix.server* 'path'+::
4816 A unix domain socket server listening on 'path'
4818 +*socket unix.dgram* '?path?'+::
4819 A unix domain socket datagram client, optionally connected to 'path'
4821 +*socket unix.dgram.server* 'path'+::
4822 A unix domain socket datagram server server listening on 'path'
4824 +*socket ?-ipv6? stream* 'addr:port'+::
4825 A TCP socket client. (See the forms for +'addr'+ below)
4827 +*socket ?-ipv6? stream.server* '?addr:?port'+::
4828 A TCP socket server (+'addr'+ defaults to +0.0.0.0+ for IPv4 or +[::]+ for IPv6).
4830 +*socket ?-ipv6? dgram* ?'addr:port'?+::
4831 A UDP socket client. If the address is not specified,
4832 the client socket will be unbound and 'sendto' must be used
4833 to indicated the destination.
4835 +*socket ?-ipv6? dgram.server* 'addr:port'+::
4836 A UDP socket server.
4839 A synonym for `pipe`
4842 A socketpair (see socketpair(2)). Like `pipe`, this command returns
4843 a list of two channels: {s1 s2}. These channels are both readable and writable.
4845 This command creates a socket connected (client) or bound (server) to the given
4848 The returned value is channel and may generally be used with the various file I/O
4849 commands (gets, puts, read, etc.), either as object-based syntax or Tcl-compatible syntax.
4851 . set f [socket stream www.google.com:80]
4853 . $f puts -nonewline "GET / HTTP/1.0\r\n\r\n"
4858 Server sockets, however support only 'accept', which is most useful in conjunction with
4861 set f [socket stream.server 80]
4863 set client [$f accept]
4866 $client puts -nonewline "HTTP/1.1 404 Not found\r\n"
4871 The address, +'addr'+, can be given in one of the following forms:
4873 1. For IPv4 socket types, an IPv4 address such as 192.168.1.1
4874 2. For IPv6 socket types, an IPv6 address such as [fe80::1234] or [::]
4877 Note that on many systems, listening on an IPv6 address such as [::] will
4878 also accept requests via IPv4.
4880 Where a hostname is specified, the +'first'+ returned address is used
4881 which matches the socket type is used.
4883 An unconnected dgram socket (either 'dgram' or 'unix.dgram') must use
4884 `sendto` to specify the destination address.
4886 The path for Unix domain sockets is automatically removed when the socket
4887 is closed. Use `close -nodelete` in the rare case where this behaviour
4888 should be avoided (e.g. after `os.fork`).
4892 +*syslog* '?options? ?priority? message'+
4894 This command sends message to system syslog facility with given
4895 priority. Valid priorities are:
4897 emerg, alert, crit, err, error, warning, notice, info, debug
4899 If a message is specified, but no priority is specified, then a
4900 priority of info is used.
4902 By default, facility user is used and the value of global tcl variable
4903 argv0 is used as ident string. However, any of the following options
4904 may be specified before priority to control these parameters:
4906 +*-facility* 'value'+::
4907 Use specified facility instead of user. The following
4908 values for facility are recognized:
4910 authpriv, cron, daemon, kernel, lpr, mail, news, syslog, user,
4913 +*-ident* 'string'+::
4914 Use given string instead of argv0 variable for ident string.
4916 +*-options* 'integer'+::
4917 Set syslog options such as +LOG_CONS+, +LOG_NDELAY+. You should
4918 use numeric values of those from your system syslog.h file,
4919 because I haven't got time to implement yet another hash
4924 The optional 'pack' extension provides commands to encode and decode binary strings.
4926 +*pack* 'varName value' *-intle|-intbe|-floatle|-floatbe|-str* 'bitwidth ?bitoffset?'+::
4927 Packs the binary representation of +'value'+ into the variable
4928 +'varName'+. The value is packed according to the given type
4929 (integer/floating point/string, big-endian/little-endian), width and bit offset.
4930 The variable is created if necessary (like `append`).
4931 The variable is expanded if necessary.
4933 +*unpack* 'binvalue' *-intbe|-intle|-uintbe|-uintle|-floatbe|-floatle|-str* 'bitpos bitwidth'+::
4934 Unpacks bits from +'binvalue'+ at bit position +'bitpos'+ and with +'bitwidth'+.
4935 Interprets the value according to the type (integer/floating point/string, big-endian/little-endian
4936 and signed/unsigned) and returns it. For integer types, +'bitwidth'+
4937 may be up to the size of a Jim Tcl integer (typically 64 bits). For floating point types,
4938 +'bitwidth'+ may be 32 bits (for single precision numbers) or 64 bits (for double precision).
4939 For the string type, both the width and the offset must be on a byte boundary (multiple of 8). Attempting to
4940 access outside the length of the value will return 0 for integer types, 0.0 for floating point types
4941 or the empty string for the string type.
4945 The optional 'zlib' extension provides a Tcl-compatible subset of the `zlib` command.
4947 +*crc32* 'data' '?startValue?'+::
4948 Returns the CRC32 checksum of a buffer. Optionally, an initial value may be specified; this is most useful
4949 for calculating the checksum of chunked data read from a stream (for instance, a pipe).
4951 +*deflate* 'string' '?level?'+::
4952 Compresses a buffer and outputs a raw, Deflate-compressed stream. Optionally, a compression level (1-9) may
4953 be specified to choose the desired speed vs. compression rate ratio.
4955 +*inflate* 'data' '?bufferSize?'+::
4956 Decompresses a raw, Deflate-compressed stream. When the uncompressed data size is known and specified, memory
4957 allocation is more efficient. Otherwise, decomperssion is chunked and therefore slower.
4959 +*gzip* 'string' '?-level level?'+::
4960 Compresses a buffer and adds a gzip header.
4962 +*gunzip* 'data' '?-buffersize size?'+::
4963 Decompresses a gzip-compressed buffer. Decompression is chunked, with a default, small buffer size of 64K
4964 which guarantees lower memory footprint at the cost of speed. It is recommended to use a bigger size, on
4965 systems without a severe memory constraint.
4969 The optional, pure-Tcl 'binary' extension provides the Tcl-compatible `binary scan` and `binary format`
4970 commands based on the low-level `pack` and `unpack` commands.
4972 See the Tcl documentation at: http://www.tcl.tk/man/tcl8.5/TclCmd/binary.htm
4974 Note that 'binary format' with f/r/R specifiers (single-precision float) uses the value of Infinity
4975 in case of overflow.
4979 The optional, pure-Tcl 'oo' extension provides object-oriented (OO) support for Jim Tcl.
4981 See the online documentation (http://jim.tcl.tk/index.html/doc/www/www/documentation/oo/) for more details.
4983 +*class* 'classname ?baseclasses? classvars'+::
4984 Create a new class, +'classname'+, with the given dictionary
4985 (+'classvars'+) as class variables. These are the initial variables
4986 which all newly created objects of this class are initialised with.
4987 If a list of baseclasses is given, methods and instance variables
4990 +*super* 'method ?args \...?'+::
4991 From within a method, invokes the given method on the base class.
4992 Note that this will only call the last baseclass given.
4996 The optional, pure-Tcl 'tree' extension implements an OO, general purpose tree structure
4997 similar to that provided by tcllib ::struct::tree (http://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/struct/struct_tree.html)
4999 A tree is a collection of nodes, where each node (except the root node) has a single parent
5000 and zero or more child nodes (ordered), as well as zero or more attribute/value pairs.
5003 Creates and returns a new tree object with a single node named "root".
5004 All operations on the tree are invoked through this object.
5007 Destroy the tree and all it's nodes. (Note that the tree will also
5008 be automatically garbage collected once it goes out of scope).
5010 +$tree *set* 'nodename key value'+::
5011 Set the value for the given attribute key.
5013 +$tree *lappend* 'nodename key value \...'+::
5014 Append to the (list) value(s) for the given attribute key, or set if not yet set.
5016 +$tree *keyexists* 'nodename key'+::
5017 Returns 1 if the given attribute key exists.
5019 +$tree *get* 'nodename key'+::
5020 Returns the value associated with the given attribute key.
5022 +$tree *getall* 'nodename'+::
5023 Returns the entire attribute dictionary associated with the given key.
5025 +$tree *depth* 'nodename'+::
5026 Returns the depth of the given node. The depth of "root" is 0.
5028 +$tree *parent* 'nodename'+::
5029 Returns the node name of the parent node, or "" for the root node.
5031 +$tree *numchildren* 'nodename'+::
5032 Returns the number of child nodes.
5034 +$tree *children* 'nodename'+::
5035 Returns a list of the child nodes.
5037 +$tree *next* 'nodename'+::
5038 Returns the next sibling node, or "" if none.
5040 +$tree *insert* 'nodename ?index?'+::
5041 Add a new child node to the given node. The index is a list index
5042 such as +3+ or +end-2+. The default index is +end+.
5043 Returns the name of the newly added node.
5045 +$tree *walk* 'nodename' *dfs|bfs* {'actionvar nodevar'} 'script'+::
5046 Walks the tree starting from the given node, either breadth first (+bfs+)
5047 depth first (+dfs+).
5048 The value +"enter"+ or +"exit"+ is stored in variable +'actionvar'+.
5049 The name of each node is stored in +'nodevar'+.
5050 The script is evaluated twice for each node, on entry and exit.
5053 Dumps the tree contents to stdout
5057 The optional tclprefix extension provides the Tcl8.6-compatible `tcl::prefix` command
5058 (http://www.tcl.tk/man/tcl8.6/TclCmd/prefix.htm) for matching strings against a table
5059 of possible values (typically commands or options).
5061 +*tcl::prefix all* 'table string'+::
5062 Returns a list of all elements in +'table'+ that begin with the prefix +'string'+.
5064 +*tcl::prefix longest* 'table string'+::
5065 Returns the longest common prefix of all elements in +'table'+ that begin with the prefix +'string'+.
5067 +*tcl::prefix match* '?options? table string'+::
5068 If +'string'+ equals one element in +'table'+ or is a prefix to
5069 exactly one element, the matched element is returned. If not, the
5070 result depends on the +-error+ option.
5072 * +*-exact*+ Accept only exact matches.
5073 * +*-message* 'string'+ Use +'string'+ in the error message at a mismatch. Default is "option".
5074 * +*-error* 'options'+ The options are used when no match is found. If +'options'+ is
5075 empty, no error is generated and an empty string is returned.
5076 Otherwise the options are used as return options when
5077 generating the error message. The default corresponds to
5082 Scriptable command line completion is supported in the interactive shell, 'jimsh', through
5083 the `tcl::autocomplete` callback. A simple implementation is provided, however this may
5084 be replaced with a custom command instead if desired.
5086 In the interactive shell, press <TAB> to activate command line completion.
5088 +*tcl::autocomplete* 'commandline'+::
5089 This command is called with the current command line when the user presses <TAB>.
5090 The command should return a list of all possible command lines that match the current command line.
5091 For example if +*pr*+ is the current command line, the list +*{prefix proc}*+ may be returned.
5095 The optional history extension provides script access to the command line editing
5096 and history support available in 'jimsh'. See 'examples/jtclsh.tcl' for an example.
5097 Note: if line editing support is not available, `history getline` acts like `gets` and
5098 the remaining subcommands do nothing.
5100 +*history load* 'filename'+::
5101 Load history from a (text) file. If the file does not exist or is not readable,
5104 +*history getline* 'prompt ?varname?'+::
5105 Displays the given prompt and allows a line to be entered. Similarly to `gets`,
5106 if +'varname'+ is given, it receives the line and the length of the line is returned,
5107 or -1 on EOF. If +'varname'+ is not given, the line is returned directly.
5109 +*history completion* 'command'+::
5110 Sets an autocompletion command (see `tcl::autocomplete`) that is active during `history getline`.
5111 If the command is empty, autocompletion is disabled.
5113 +*history add* 'line'+::
5114 Adds the given line to the history buffer.
5116 +*history save* 'filename'+::
5117 Saves the current history buffer to the given file.
5120 Displays the current history buffer to standard output.
5124 Provides namespace-related functions. See also: http://www.tcl.tk/man/tcl8.6/TclCmd/namespace.htm
5126 +*namespace code* 'script'+::
5127 Captures the current namespace context for later execution of
5128 the script +'script'+. It returns a new script in which script has
5129 been wrapped in a +*namespace inscope*+ command.
5131 +*namespace current*+::
5132 Returns the fully-qualified name for the current namespace.
5134 +*namespace delete* '?namespace ...?'+::
5135 Deletes all commands and variables with the given namespace prefixes.
5137 +*namespace eval* 'namespace arg ?arg...?'+::
5138 Activates a namespace called +'namespace'+ and evaluates some code in that context.
5140 +*namespace origin* 'command'+::
5141 Returns the fully-qualified name of the original command to which the imported command +'command'+ refers.
5143 +*namespace parent* ?namespace?+::
5144 Returns the fully-qualified name of the parent namespace for namespace +'namespace'+, if given, otherwise
5145 for the current namespace.
5147 +*namespace qualifiers* 'string'+::
5148 Returns any leading namespace qualifiers for +'string'+
5150 +*namespace tail* 'string'+::
5151 Returns the simple name at the end of a qualified string.
5153 +*namespace upvar* 'namespace ?arg...?'+::
5154 This command arranges for zero or more local variables in the current procedure to refer to variables in +'namespace'+
5156 +*namespace which* '?-command|-variable? name'+::
5157 Looks up +'name'+ as either a command (the default) or variable and returns its fully-qualified name.
5161 The optional 'interp' command allows sub-interpreters to be created where commands may be run
5162 independently (but synchronously) of the main interpreter.
5165 Creates and returns a new interpreter object (command).
5166 The created interpeter contains any built-in commands along with static extensions,
5167 but does not include any dynamically loaded commands (package require, load).
5168 These must be reloaded in the child interpreter if required.
5170 +*$interp delete*+::
5171 Deletes the interpeter object.
5173 +*$interp eval* 'script' ...+::
5174 Evaluates a script in the context for the child interpreter, in the same way as 'eval'.
5176 +*$interp alias* 'alias childcmd parentcmd ?arg ...?'+::
5177 Similar to 'alias', but creates a command, +'childcmd'+, in the child interpreter that is an
5178 alias for +'parentcmd'+ in the parent interpreter, with the given, fixed arguments.
5179 The alias may be deleted in the child with 'rename'.
5181 [[BuiltinVariables]]
5185 The following global variables are created automatically
5189 This variable is set by Jim as an array
5190 whose elements are the environment variables for the process.
5191 Reading an element will return the value of the corresponding
5192 environment variable.
5193 This array is initialised at startup from the `env` command.
5194 It may be modified and will affect the environment passed to
5195 commands invoked with `exec`.
5198 This variable is set by Jim as an array containing information
5199 about the platform on which Jim was built. Currently this includes
5200 'os' and 'platform'.
5203 This variable contains a list of paths to search for packages.
5204 It defaults to a location based on where jim is installed
5205 (e.g. +/usr/local/lib/jim+), but may be changed by +jimsh+
5206 or the embedding application. Note that +jimsh+ will consider
5207 the environment variable +$JIMLIB+ to be a list of colon-separated
5208 list of paths to add to +*auto_path*+.
5211 This variable holds the value of the -errorcode return
5212 option set by the most recent error that occurred in this
5213 interpreter. This list value represents additional information
5214 about the error in a form that is easy to process with
5215 programs. The first element of the list identifies a general
5216 class of errors, and determines the format of the rest of
5217 the list. The following formats for -errorcode return options
5218 are used by the Tcl core; individual applications may define
5219 additional formats. Currently only `exec` sets this variable.
5220 Otherwise it will be +NONE+.
5222 The following global variables are set by jimsh.
5224 +*tcl_interactive*+::
5225 This variable is set to 1 if jimsh is started in interactive mode
5229 This variable is set by Jim as an array containing information
5230 about the platform upon which Jim was built. The following is an
5231 example of the contents of this array.
5233 tcl_platform(byteOrder) = littleEndian
5234 tcl_platform(engine) = Jim
5235 tcl_platform(os) = Darwin
5236 tcl_platform(platform) = unix
5237 tcl_platform(pointerSize) = 8
5238 tcl_platform(threaded) = 0
5239 tcl_platform(wordSize) = 8
5240 tcl_platform(pathSeparator) = :
5243 If jimsh is invoked to run a script, this variable contains the name
5247 If jimsh is invoked to run a script, this variable contains a list
5248 of any arguments supplied to the script.
5251 If jimsh is invoked to run a script, this variable contains the number
5252 of arguments supplied to the script.
5255 The value of argv[0] when jimsh was invoked.
5257 The following variables have special meaning to Jim Tcl:
5260 If this variable is set, it is considered to be a list of scripts to evaluate
5261 when the current proc exits (local variables), or the interpreter exits (global variable).
5264 +*history::multiline*+::
5265 If this variable is set to "1", interactive line editing operates in multiline mode.
5266 That is, long lines will wrap across multiple lines rather than scrolling within a
5269 CHANGES IN PREVIOUS RELEASES
5270 ----------------------------
5274 1. +platform_tcl()+ settings are now automatically determined
5275 2. Add aio `$handle filename`
5276 3. Add `info channels`
5277 4. The 'bio' extension is gone. Now `aio` supports 'copyto'.
5278 5. Add `exists` command
5279 6. Add the pure-Tcl 'oo' extension
5280 7. The `exec` command now only uses vfork(), not fork()
5281 8. Unit test framework is less verbose and more Tcl-compatible
5282 9. Optional UTF-8 support
5283 10. Optional built-in regexp engine for better Tcl compatibility and UTF-8 support
5284 11. Command line editing in interactive mode, e.g. 'jimsh'
5288 1. `source` now checks that a script is complete (.i.e. not missing a brace)
5289 2. 'info complete' now uses the real parser and so is 100% accurate
5290 3. Better access to live stack frames with 'info frame', `stacktrace` and `stackdump`
5291 4. `tailcall` no longer loses stack trace information
5292 5. Add `alias` and `curry`
5293 6. `lambda`, `alias` and `curry` are implemented via `tailcall` for efficiency
5294 7. `local` allows procedures to be deleted automatically at the end of the current procedure
5295 8. udp sockets are now supported for both clients and servers.
5296 9. vfork-based exec is now working correctly
5297 10. Add 'file tempfile'
5298 11. Add 'socket pipe'
5299 12. Enhance 'try ... on ... finally' to be more Tcl 8.6 compatible
5300 13. It is now possible to `return` from within `try`
5301 14. IPv6 support is now included
5303 16. Event handlers works better if an error occurs. eof handler has been removed.
5304 17. `exec` now sets $::errorCode, and catch sets opts(-errorcode) for exit status
5305 18. Command pipelines via open "|..." are now supported
5306 19. `pid` can now return pids of a command pipeline
5307 20. Add 'info references'
5308 21. Add support for 'after +'ms'+', 'after idle', 'after info', `update`
5309 22. `exec` now sets environment based on $::env
5311 24. Add support for 'lsort -index'
5315 1. Add support to `exec` for '>&', '>>&', '|&', '2>@1'
5316 2. Fix `exec` error messages when special token (e.g. '>') is the last token
5317 3. Fix `subst` handling of backslash escapes.
5318 4. Allow abbreviated options for `subst`
5319 5. Add support for `return`, `break`, `continue` in subst
5320 6. Many `expr` bug fixes
5321 7. Add support for functions in `expr` (e.g. int(), abs()), and also 'in', 'ni' list operations
5322 8. The variable name argument to `regsub` is now optional
5323 9. Add support for 'unset -nocomplain'
5324 10. Add support for list commands: `lassign`, `lrepeat`
5325 11. Fully-functional `lsearch` is now implemented
5326 12. Add 'info nameofexecutable' and 'info returncodes'
5327 13. Allow `catch` to determine what return codes are caught
5328 14. Allow `incr` to increment an unset variable by first setting to 0
5329 15. Allow 'args' and optional arguments to the left or required arguments in `proc`
5331 17. Add 'try ... finally' command
5337 Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
5338 Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
5339 Copyright 2005 patthoyts - Pat Thoyts <patthoyts@users.sf.net>
5340 Copyright 2008 oharboe - Oyvind Harboe - oyvind.harboe@zylin.com
5341 Copyright 2008 Andrew Lunn <andrew@lunn.ch>
5342 Copyright 2008 Duane Ellis <openocd@duaneellis.com>
5343 Copyright 2008 Uwe Klein <uklein@klein-messgeraete.de>
5344 Copyright 2009 Steve Bennett <steveb@workware.net.au>
5347 Redistribution and use in source and binary forms, with or without
5348 modification, are permitted provided that the following conditions
5350 1. Redistributions of source code must retain the above copyright
5351 notice, this list of conditions and the following disclaimer.
5352 2. Redistributions in binary form must reproduce the above
5353 copyright notice, this list of conditions and the following
5354 disclaimer in the documentation and/or other materials
5355 provided with the distribution.
5357 THIS SOFTWARE IS PROVIDED BY THE JIM TCL PROJECT ``AS IS'' AND ANY
5358 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
5359 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
5360 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
5361 JIM TCL PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
5362 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
5363 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
5364 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
5365 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
5366 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
5367 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
5368 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5370 The views and conclusions contained in the software and documentation
5371 are those of the authors and should not be interpreted as representing
5372 official policies, either expressed or implied, of the Jim Tcl Project.