6 Jim Tcl v0.76+ - reference manual for the Jim Tcl scripting language
16 jimsh -e '<immediate-script>'
21 * <<CommandIndex,Command Reference>>
22 * <<OperatorPrecedence,Operator Precedence>>
23 * <<BuiltinVariables, Builtin Variables>>
24 * <<BackslashSequences, Backslash Sequences>>
28 Jim Tcl is a small footprint reimplementation of the Tcl scripting language.
29 The core language engine is compatible with Tcl 8.5+, while implementing
30 a significant subset of the Tcl 8.6 command set, plus additional features
31 available only in Jim Tcl.
33 Some notable differences with Tcl 8.5/8.6 are:
35 1. Object-based I/O (aio), but with a Tcl-compatibility layer
36 2. I/O: Support for sockets and pipes including udp, unix domain sockets and IPv6
38 4. Support for references (`ref`/`getref`/`setref`) and garbage collection
39 5. Builtin dictionary type (`dict`) with some limitations compared to Tcl 8.6
40 6. `env` command to access environment variables
41 7. Operating system features: `os.fork`, `os.wait`, `os.uptime`, `signal`, `alarm`, `sleep`
42 8. Much better error reporting. `info stacktrace` as a replacement for '$errorInfo', '$errorCode'
43 9. Support for "static" variables in procedures
44 10. Threads and coroutines are not supported
45 11. Command and variable traces are not supported
46 12. Built-in command line editing
47 13. Expression shorthand syntax: +$(...)+
48 14. Modular build allows many features to be omitted or built as dynamic, loadable modules
49 15. Highly suitable for use in an embedded environment
50 16. Support for UDP, IPv6, Unix-Domain sockets in addition to TCP sockets
54 Changes between 0.76 and 0.77
55 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
56 1. Add support for `aio sync`
57 2. Add SSL and TLS support in aio
59 Changes between 0.75 and 0.76
60 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
61 1. Add support for `file link`
62 2. `glob` now supports the '--tails' option
63 3. Add support for `string cat`
64 4. Allow `info source` to add source info
66 Changes between 0.74 and 0.75
67 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
68 1. `binary`, `pack` and `unpack` now support floating point
69 2. `file copy` '-force' handles source and target as the same file
70 3. `format` now supports +%b+ for binary conversion
71 4. `lsort` now supports '-unique' and '-real'
72 5. Add support for half-close with `aio close` ?r|w?
73 6. Add `socket pair` for a bidirectional pipe
74 7. Add '--random-hash' to randomise hash tables for greater security
75 8. `dict` now supports 'for', 'values', 'incr', 'append', 'lappend', 'update', 'info' and 'replace'
76 9. `file stat` no longer requires the variable name
78 Changes between 0.73 and 0.74
79 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
80 1. Numbers with leading zeros are treated as decimal, not octal
82 3. Add LFS (64 bit) support for `aio seek`, `aio tell`, `aio copyto`, `file copy`
83 4. `string compare` and `string equal` now support '-length'
84 5. `glob` now supports '-directory'
86 Changes between 0.72 and 0.73
87 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
88 1. Built-in regexp now support non-capturing parentheses: (?:...)
89 2. Add `string replace`
90 3. Add `string totitle`
92 5. Add +build-jim-ext+ for easy separate building of loadable modules (extensions)
93 6. `local` now works with any command, not just procs
94 7. Add `info alias` to access the target of an alias
95 8. UTF-8 encoding past the basic multilingual plane (BMP) is supported
98 11. Most extensions are now enabled by default
99 12. Add support for namespaces and the `namespace` command
102 Changes between 0.71 and 0.72
103 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
104 1. procs now allow 'args' and optional parameters in any position
105 2. Add Tcl-compatible expr functions, `rand()`, `srand()` and `pow()`
106 3. Add support for the '-force' option to `file delete`
107 4. Better diagnostics when `source` fails to load a script with a missing quote or bracket
108 5. New +tcl_platform(pathSeparator)+
109 6. Add support settings the modification time with `file mtime`
110 7. `exec` is now fully supported on win32 (mingw32)
111 8. `file join`, `pwd`, `glob` etc. now work for mingw32
112 9. Line editing is now supported for the win32 console (mingw32)
113 10. Add `aio listen` command
115 Changes between 0.70 and 0.71
116 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
117 1. Allow 'args' to be renamed in procs
118 2. Add +$(...)+ shorthand syntax for expressions
119 3. Add automatic reference variables in procs with +&var+ syntax
120 4. Support +jimsh --version+
121 5. Additional variables in +tcl_platform()+
122 6. `local` procs now push existing commands and `upcall` can call them
123 7. Add `loop` command (TclX compatible)
124 8. Add `aio buffering` command
125 9. `info complete` can now return the missing character
126 10. `binary format` and `binary scan` are now (optionally) supported
127 11. Add `string byterange`
128 12. Built-in regexp now support non-greedy repetition (*?, +?, ??)
132 Tcl stands for 'tool command language' and is pronounced
133 'http://www.oxforddictionaries.com/definition/american_english/tickle[tickle]'.
134 It is actually two things: a language and a library.
136 First, Tcl is a simple textual language, intended primarily for
137 issuing commands to interactive programs such as text editors,
138 debuggers, illustrators, and shells. It has a simple syntax and is also
139 programmable, so Tcl users can write command procedures to provide more
140 powerful commands than those in the built-in set.
142 Second, Tcl is a library package that can be embedded in application
143 programs. The Tcl library consists of a parser for the Tcl language,
144 routines to implement the Tcl built-in commands, and procedures that
145 allow each application to extend Tcl with additional commands specific
146 to that application. The application program generates Tcl commands and
147 passes them to the Tcl parser for execution. Commands may be generated
148 by reading characters from an input source, or by associating command
149 strings with elements of the application's user interface, such as menu
150 entries, buttons, or keystrokes.
152 When the Tcl library receives commands it parses them into component
153 fields and executes built-in commands directly. For commands implemented
154 by the application, Tcl calls back to the application to execute the
155 commands. In many cases commands will invoke recursive invocations of the
156 Tcl interpreter by passing in additional strings to execute (procedures,
157 looping commands, and conditional commands all work in this way).
159 An application program gains three advantages by using Tcl for its command
160 language. First, Tcl provides a standard syntax: once users know Tcl,
161 they will be able to issue commands easily to any Tcl-based application.
162 Second, Tcl provides programmability. All a Tcl application needs
163 to do is to implement a few application-specific low-level commands.
164 Tcl provides many utility commands plus a general programming interface
165 for building up complex command procedures. By using Tcl, applications
166 need not re-implement these features.
168 Third, Tcl can be used as a common language for communicating between
169 applications. Inter-application communication is not built into the
170 Tcl core described here, but various add-on libraries, such as the Tk
171 toolkit, allow applications to issue commands to each other. This makes
172 it possible for applications to work together in much more powerful ways
173 than was previously possible.
175 Fourth, Jim Tcl includes a command processor, +jimsh+, which can be
176 used to run standalone Tcl scripts, or to run Tcl commands interactively.
178 This manual page focuses primarily on the Tcl language. It describes
179 the language syntax and the built-in commands that will be available
180 in any application based on Tcl. The individual library procedures are
181 described in more detail in separate manual pages, one per procedure.
183 JIMSH COMMAND INTERPRETER
184 -------------------------
185 A simple, but powerful command processor, +jimsh+, is part of Jim Tcl.
186 It may be invoked in interactive mode as:
190 or to process the Tcl script in a file with:
194 It may also be invoked to execute an immediate script with:
200 Interactive mode reads Tcl commands from standard input, evaluates
201 those commands and prints the results.
204 Welcome to Jim version 0.73, Copyright (c) 2005-8 Salvatore Sanfilippo
207 . lsort [info commands p*]
208 package parray pid popen proc puts pwd
209 . foreach i {a b c} {
216 invalid command name "bad"
220 If +jimsh+ is configured with line editing (it is by default) and a VT-100-compatible
221 terminal is detected, Emacs-style line editing commands are available, including:
222 arrow keys, +\^W+ to erase a word, +\^U+ to erase the line, +^R+ for reverse incremental search
223 in history. Additionally, the +h+ command may be used to display the command history.
225 Command line history is automatically saved and loaded from +~/.jim_history+
227 In interactive mode, +jimsh+ automatically runs the script +~/.jimrc+ at startup
232 The central data structure in Tcl is an interpreter (C type 'Jim_Interp').
233 An interpreter consists of a set of command bindings, a set of variable
234 values, and a few other miscellaneous pieces of state. Each Tcl command
235 is interpreted in the context of a particular interpreter.
237 Some Tcl-based applications will maintain multiple interpreters
238 simultaneously, each associated with a different widget or portion of
239 the application. Interpreters are relatively lightweight structures.
240 They can be created and deleted quickly, so application programmers should
241 feel free to use multiple interpreters if that simplifies the application.
245 Tcl supports only one type of data: strings. All commands, all arguments
246 to commands, all command results, and all variable values are strings.
248 Where commands require numeric arguments or return numeric results,
249 the arguments and results are passed as strings. Many commands expect
250 their string arguments to have certain formats, but this interpretation
251 is up to the individual commands. For example, arguments often contain
252 Tcl command strings, which may get executed as part of the commands.
253 The easiest way to understand the Tcl interpreter is to remember that
254 everything is just an operation on a string. In many cases Tcl constructs
255 will look similar to more structured constructs from other languages.
256 However, the Tcl constructs are not structured at all; they are just
257 strings of characters, and this gives them a different behaviour than
258 the structures they may look like.
260 Although the exact interpretation of a Tcl string depends on who is doing
261 the interpretation, there are three common forms that strings take:
262 commands, expressions, and lists. The major sections below discuss
263 these three forms in more detail.
267 The Tcl language has syntactic similarities to both the Unix shells
268 and Lisp. However, the interpretation of commands is different
269 in Tcl than in either of those other two systems.
270 A Tcl command string consists of one or more commands separated
271 by newline characters or semi-colons.
272 Each command consists of a collection of fields separated by
273 white space (spaces or tabs).
274 The first field must be the name of a command, and the
275 additional fields, if any, are arguments that will be passed to
276 that command. For example, the command:
280 has three fields: the first, `set`, is the name of a Tcl command, and
281 the last two, 'a' and '22', will be passed as arguments to
282 the `set` command. The command name may refer either to a built-in
283 Tcl command, an application-specific command bound in with the library
284 procedure 'Jim_CreateCommand', or a command procedure defined with the
285 `proc` built-in command.
287 Arguments are passed literally as text strings. Individual commands may
288 interpret those strings in any fashion they wish. The `set` command,
289 for example, will treat its first argument as the name of a variable
290 and its second argument as a string value to assign to that variable.
291 For other commands arguments may be interpreted as integers, lists,
292 file names, or Tcl commands.
294 Command names should normally be typed completely (e.g. no abbreviations).
295 However, if the Tcl interpreter cannot locate a command it invokes a
296 special command named `unknown` which attempts to find or create the
299 For example, at many sites `unknown` will search through library
300 directories for the desired command and create it as a Tcl procedure if
301 it is found. The `unknown` command often provides automatic completion
302 of abbreviated commands, but usually only for commands that were typed
305 It's probably a bad idea to use abbreviations in command scripts and
306 other forms that will be re-used over time: changes to the command set
307 may cause abbreviations to become ambiguous, resulting in scripts that
312 If the first non-blank character in a command is +\#+, then everything
313 from the +#+ up through the next newline character is treated as
314 a comment and ignored. When comments are embedded inside nested
315 commands (e.g. fields enclosed in braces) they must have properly-matched
316 braces (this is necessary because when Tcl parses the top-level command
317 it doesn't yet know that the nested field will be used as a command so
318 it cannot process the nested comment character as a comment).
320 GROUPING ARGUMENTS WITH DOUBLE-QUOTES
321 -------------------------------------
322 Normally each argument field ends at the next white space, but
323 double-quotes may be used to create arguments with embedded space.
325 If an argument field begins with a double-quote, then the argument isn't
326 terminated by white space (including newlines) or a semi-colon (see below
327 for information on semi-colons); instead it ends at the next double-quote
328 character. The double-quotes are not included in the resulting argument.
329 For example, the command
331 set a "This is a single argument"
333 will pass two arguments to `set`: 'a' and 'This is a single argument'.
335 Within double-quotes, command substitutions, variable substitutions,
336 and backslash substitutions still occur, as described below. If the
337 first character of a command field is not a quote, then quotes receive
338 no special interpretation in the parsing of that field.
340 GROUPING ARGUMENTS WITH BRACES
341 ------------------------------
342 Curly braces may also be used for grouping arguments. They are similar
343 to quotes except for two differences. First, they nest; this makes them
344 easier to use for complicated arguments like nested Tcl command strings.
345 Second, the substitutions described below for commands, variables, and
346 backslashes do *not* occur in arguments enclosed in braces, so braces
347 can be used to prevent substitutions where they are undesirable.
349 If an argument field begins with a left brace, then the argument ends
350 at the matching right brace. Tcl will strip off the outermost layer
351 of braces and pass the information between the braces to the command
352 without any further modification. For example, in the command
354 set a {xyz a {b c d}}
356 the `set` command will receive two arguments: 'a'
359 When braces or quotes are in effect, the matching brace or quote need
360 not be on the same line as the starting quote or brace; in this case
361 the newline will be included in the argument field along with any other
362 characters up to the matching brace or quote. For example, the `eval`
363 command takes one argument, which is a command string; `eval` invokes
364 the Tcl interpreter to execute the command string. The command
371 will assign the value '22' to 'a' and '33' to 'b'.
373 If the first character of a command field is not a left
374 brace, then neither left nor right
375 braces in the field will be treated specially (except as part of
376 variable substitution; see below).
378 COMMAND SUBSTITUTION WITH BRACKETS
379 ----------------------------------
380 If an open bracket occurs in a field of a command, then command
381 substitution occurs (except for fields enclosed in braces). All of the
382 text up to the matching close bracket is treated as a Tcl command and
383 executed immediately. Then the result of that command is substituted
384 for the bracketed text. For example, consider the command
388 When the `set` command has only a single argument, it is the name of a
389 variable and `set` returns the contents of that variable. In this case,
390 if variable 'b' has the value 'foo', then the command above is equivalent
395 Brackets can be used in more complex ways. For example, if the variable
396 'b' has the value 'foo' and the variable 'c' has the value 'gorp',
399 set a xyz[set b].[set c]
401 is equivalent to the command
406 A bracketed command may contain multiple commands separated by newlines
407 or semi-colons in the usual fashion. In this case the value of the last
408 command is used for substitution. For example, the command
413 is equivalent to the command
418 If a field is enclosed in braces then the brackets and the characters
419 between them are not interpreted specially; they are passed through to
420 the argument verbatim.
422 VARIABLE SUBSTITUTION WITH $
423 ----------------------------
424 The dollar sign (+$+) may be used as a special shorthand form for
425 substituting variable values. If +$+ appears in an argument that isn't
426 enclosed in braces then variable substitution will occur. The characters
427 after the +$+, up to the first character that isn't a number, letter,
428 or underscore, are taken as a variable name and the string value of that
429 variable is substituted for the name.
431 For example, if variable 'foo' has the value 'test', then the command
435 is equivalent to the command
439 There are two special forms for variable substitution. If the next
440 character after the name of the variable is an open parenthesis, then
441 the variable is assumed to be an array name, and all of the characters
442 between the open parenthesis and the next close parenthesis are taken as
443 an index into the array. Command substitutions and variable substitutions
444 are performed on the information between the parentheses before it is
447 For example, if the variable 'x' is an array with one element named
448 'first' and value '87' and another element named '14' and value 'more',
451 set a xyz$x(first)zyx
453 is equivalent to the command
457 If the variable 'index' has the value '14', then the command
459 set a xyz$x($index)zyx
461 is equivalent to the command
465 For more information on arrays, see VARIABLES AND ARRAYS below.
467 The second special form for variables occurs when the dollar sign is
468 followed by an open curly brace. In this case the variable name consists
469 of all the characters up to the next curly brace.
471 Array references are not possible in this form: the name between braces
472 is assumed to refer to a scalar variable. For example, if variable
473 'foo' has the value 'test', then the command
477 is equivalent to the command
482 Variable substitution does not occur in arguments that are enclosed in
483 braces: the dollar sign and variable name are passed through to the
486 The dollar sign abbreviation is simply a shorthand form. +$a+ is
487 completely equivalent to +[set a]+; it is provided as a convenience
490 SEPARATING COMMANDS WITH SEMI-COLONS
491 ------------------------------------
492 Normally, each command occupies one line (the command is terminated by a
493 newline character). However, semi-colon (+;+) is treated as a command
494 separator character; multiple commands may be placed on one line by
495 separating them with a semi-colon. Semi-colons are not treated as
496 command separators if they appear within curly braces or double-quotes.
498 BACKSLASH SUBSTITUTION
499 ----------------------
500 Backslashes may be used to insert non-printing characters into command
501 fields and also to insert special characters like braces and brackets
502 into fields without them being interpreted specially as described above.
504 The backslash sequences understood by the Tcl interpreter are
505 listed below. In each case, the backslash
506 sequence is replaced by the given character:
507 [[BackslashSequences]]
518 Carriage-return (0xd).
541 +{backslash}<space>+::
542 Space ( ): doesn't terminate argument.
545 Semi-colon: doesn't terminate command.
550 +{backslash}<newline>+::
551 Nothing: this joins two lines together
552 into a single line. This backslash feature is unique in that
553 it will be applied even when the sequence occurs within braces.
555 +{backslash}{backslash}+::
556 Backslash ('{backslash}').
559 The digits +'ddd'+ (one, two, or three of them) give the octal value of
560 the character. Note that Jim supports null characters in strings.
563 +{backslash}u\{nnn\}+::
564 +{backslash}Unnnnnnnn+::
565 The UTF-8 encoding of the unicode codepoint represented by the hex digits, +'nnnn'+, is inserted.
566 The 'u' form allows for one to four hex digits.
567 The 'U' form allows for one to eight hex digits.
568 The 'u\{nnn\}' form allows for one to eight hex digits, but makes it easier to insert
569 characters UTF-8 characters which are followed by a hex digit.
571 For example, in the command
575 the second argument to `set` will be +{x[ yza+.
577 If a backslash is followed by something other than one of the options
578 described above, then the backslash is transmitted to the argument
579 field without any special processing, and the Tcl scanner continues
580 normal processing with the next character. For example, in the
585 The first argument to `set` will be +{backslash}*a+ and the second
586 argument will be +{backslash}{foo+.
588 If an argument is enclosed in braces, then backslash sequences inside
589 the argument are parsed but no substitution occurs (except for
590 backslash-newline): the backslash
591 sequence is passed through to the argument as is, without making
592 any special interpretation of the characters in the backslash sequence.
593 In particular, backslashed braces are not counted in locating the
594 matching right brace that terminates the argument.
600 the second argument to `set` will be +{backslash}{abc+.
602 This backslash mechanism is not sufficient to generate absolutely
603 any argument structure; it only covers the
604 most common cases. To produce particularly complicated arguments
605 it is probably easiest to use the `format` command along with
606 command substitution.
608 STRING AND LIST INDEX SPECIFICATIONS
609 ------------------------------------
611 Many string and list commands take one or more 'index' parameters which
612 specify a position in the string relative to the start or end of the string/list.
614 The index may be one of the following forms:
617 A simple integer, where '0' refers to the first element of the string
620 +integer+integer+ or::
622 The sum or difference of the two integers. e.g. +2+3+ refers to the 5th element.
623 This is useful when used with (e.g.) +$i+1+ rather than the more verbose
627 The last element of the string or list.
630 The 'nth-from-last' element of the string or list.
634 1. A command is just a string.
635 2. Within a string commands are separated by newlines or semi-colons
636 (unless the newline or semi-colon is within braces or brackets
638 3. A command consists of fields. The first field is the name of the command.
639 The other fields are strings that are passed to that command as arguments.
640 4. Fields are normally separated by white space.
641 5. Double-quotes allow white space and semi-colons to appear within
643 Command substitution, variable substitution, and backslash substitution
644 still occur inside quotes.
645 6. Braces defer interpretation of special characters.
646 If a field begins with a left brace, then it consists of everything
647 between the left brace and the matching right brace. The
648 braces themselves are not included in the argument.
649 No further processing is done on the information between the braces
650 except that backslash-newline sequences are eliminated.
651 7. If a field doesn't begin with a brace then backslash,
652 variable, and command substitution are done on the field. Only a
653 single level of processing is done: the results of one substitution
654 are not scanned again for further substitutions or any other
655 special treatment. Substitution can
656 occur on any field of a command, including the command name
657 as well as the arguments.
658 8. If the first non-blank character of a command is a +\#+, everything
659 from the +#+ up through the next newline is treated as a comment
664 The second major interpretation applied to strings in Tcl is
665 as expressions. Several commands, such as `expr`, `for`,
666 and `if`, treat one or more of their arguments as expressions
667 and call the Tcl expression processors ('Jim_ExprLong',
668 'Jim_ExprBoolean', etc.) to evaluate them.
670 The operators permitted in Tcl expressions are a subset of
671 the operators permitted in C expressions, and they have the
672 same meaning and precedence as the corresponding C operators.
673 Expressions almost always yield numeric results
674 (integer or floating-point values).
675 For example, the expression
681 Tcl expressions differ from C expressions in the way that
682 operands are specified, and in that Tcl expressions support
683 non-numeric operands and string comparisons.
685 A Tcl expression consists of a combination of operands, operators,
688 White space may be used between the operands and operators and
689 parentheses; it is ignored by the expression processor.
690 Where possible, operands are interpreted as integer values.
692 Integer values may be specified in decimal (the normal case) or in
693 hexadecimal (if the first two characters of the operand are '0x').
694 Note that Jim Tcl does *not* treat numbers with leading zeros as octal.
696 If an operand does not have one of the integer formats given
697 above, then it is treated as a floating-point number if that is
698 possible. Floating-point numbers may be specified in any of the
699 ways accepted by an ANSI-compliant C compiler (except that the
700 'f', 'F', 'l', and 'L' suffixes will not be permitted in
701 most installations). For example, all of the
702 following are valid floating-point numbers: 2.1, 3., 6e4, 7.91e+16.
704 If no numeric interpretation is possible, then an operand is left
705 as a string (and only a limited set of operators may be applied to
708 1. Operands may be specified in any of the following ways:
710 2. As a numeric value, either integer or floating-point.
712 3. As a Tcl variable, using standard '$' notation.
713 The variable's value will be used as the operand.
715 4. As a string enclosed in double-quotes.
716 The expression parser will perform backslash, variable, and
717 command substitutions on the information between the quotes,
718 and use the resulting value as the operand
720 5. As a string enclosed in braces.
721 The characters between the open brace and matching close brace
722 will be used as the operand without any substitutions.
724 6. As a Tcl command enclosed in brackets.
725 The command will be executed and its result will be used as
728 Where substitutions occur above (e.g. inside quoted strings), they
729 are performed by the expression processor.
730 However, an additional layer of substitution may already have
731 been performed by the command parser before the expression
732 processor was called.
734 As discussed below, it is usually best to enclose expressions
735 in braces to prevent the command parser from performing substitutions
738 For some examples of simple expressions, suppose the variable 'a' has
739 the value 3 and the variable 'b' has the value 6. Then the expression
740 on the left side of each of the lines below will evaluate to the value
741 on the right side of the line:
746 {word one} < "word $a" 0
748 The valid operators are listed below, grouped in decreasing order
750 [[OperatorPrecedence]]
751 +int() double() round() abs(), rand(), srand()+::
752 Unary functions (except rand() which takes no arguments)
753 * +'int()'+ converts the numeric argument to an integer by truncating down.
754 * +'double()'+ converts the numeric argument to floating point.
755 * +'round()'+ converts the numeric argument to the closest integer value.
756 * +'abs()'+ takes the absolute value of the numeric argument.
757 * +'rand()'+ returns a pseudo-random floating-point value in the range (0,1).
758 * +'srand()'+ takes an integer argument to (re)seed the random number generator. Returns the first random number from that seed.
760 +sin() cos() tan() asin() acos() atan() sinh() cosh() tanh() ceil() floor() exp() log() log10() sqrt()+::
761 Unary math functions.
762 If Jim is compiled with math support, these functions are available.
765 Unary minus, unary plus, bit-wise NOT, logical NOT. None of these operands
766 may be applied to string operands, and bit-wise NOT may be
767 applied only to integers.
770 Power. e.g. 'x^y^'. If Jim is compiled with math support, supports doubles and
771 integers. Otherwise supports integers only. (Note that the math-function form
772 has the same highest precedence)
775 Multiply, divide, remainder. None of these operands may be
776 applied to string operands, and remainder may be applied only
780 Add and subtract. Valid for any numeric operands.
783 Left and right shift, left and right rotate. Valid for integer operands only.
786 Boolean less, greater, less than or equal, and greater than or equal.
787 Each operator produces 1 if the condition is true, 0 otherwise.
788 These operators may be applied to strings as well as numeric operands,
789 in which case string comparison is used.
792 Boolean equal and not equal. Each operator produces a zero/one result.
793 Valid for all operand types. *Note* that values will be converted to integers
794 if possible, then floating point types, and finally strings will be compared.
795 It is recommended that 'eq' and 'ne' should be used for string comparison.
798 String equal and not equal. Uses the string value directly without
799 attempting to convert to a number first.
802 String in list and not in list. For 'in', result is 1 if the left operand (as a string)
803 is contained in the right operand (as a list), or 0 otherwise. The result for
804 +{$a ni $list}+ is equivalent to +{!($a in $list)}+.
807 Bit-wise AND. Valid for integer operands only.
810 Bit-wise OR. Valid for integer operands only.
813 Bit-wise exclusive OR. Valid for integer operands only.
816 Logical AND. Produces a 1 result if both operands are non-zero, 0 otherwise.
817 Valid for numeric operands only (integers or floating-point).
820 Logical OR. Produces a 0 result if both operands are zero, 1 otherwise.
821 Valid for numeric operands only (integers or floating-point).
824 If-then-else, as in C. If +'x'+
825 evaluates to non-zero, then the result is the value of +'y'+.
826 Otherwise the result is the value of +'z'+.
827 The +'x'+ operand must have a numeric value, while +'y'+ and +'z'+ can
830 See the C manual for more details on the results
831 produced by each operator.
832 All of the binary operators group left-to-right within the same
833 precedence level. For example, the expression
839 The +&&+, +||+, and +?:+ operators have 'lazy evaluation', just as
840 in C, which means that operands are not evaluated if they are not
841 needed to determine the outcome. For example, in
845 only one of +[a]+ or +[b]+ will actually be evaluated,
846 depending on the value of +$v+.
848 All internal computations involving integers are done with the C
849 type 'long long' if available, or 'long' otherwise, and all internal
850 computations involving floating-point are done with the C type
853 When converting a string to floating-point, exponent overflow is
854 detected and results in a Tcl error.
855 For conversion to integer from string, detection of overflow depends
856 on the behaviour of some routines in the local C library, so it should
857 be regarded as unreliable.
858 In any case, overflow and underflow are generally not detected
859 reliably for intermediate results.
861 Conversion among internal representations for integer, floating-point,
862 and string operands is done automatically as needed.
863 For arithmetic computations, integers are used until some
864 floating-point number is introduced, after which floating-point is used.
869 yields the result 1, while
872 5 / ( [string length "abcd"] + 0.0 )
874 both yield the result 1.25.
876 String values may be used as operands of the comparison operators,
877 although the expression evaluator tries to do comparisons as integer
878 or floating-point when it can.
879 If one of the operands of a comparison is a string and the other
880 has a numeric value, the numeric operand is converted back to
881 a string using the C 'sprintf' format specifier
882 '%d' for integers and '%g' for floating-point values.
883 For example, the expressions
888 both evaluate to 1. The first comparison is done using integer
889 comparison, and the second is done using string comparison after
890 the second operand is converted to the string '18'.
892 In general it is safest to enclose an expression in braces when
893 entering it in a command: otherwise, if the expression contains
894 any white space then the Tcl interpreter will split it
895 among several arguments. For example, the command
899 results in three arguments being passed to `expr`: +$a+,
900 \+, and +$b+. In addition, if the expression isn't in braces
901 then the Tcl interpreter will perform variable and command substitution
902 immediately (it will happen in the command parser rather than in
903 the expression parser). In many cases the expression is being
904 passed to a command that will evaluate the expression later (or
905 even many times if, for example, the expression is to be used to
906 decide when to exit a loop). Usually the desired goal is to re-do
907 the variable or command substitutions each time the expression is
908 evaluated, rather than once and for all at the beginning. For example,
911 for {set i 1} $i<=10 {incr i} {...} ** WRONG **
913 is probably intended to iterate over all values of +i+ from 1 to 10.
914 After each iteration of the body of the loop, `for` will pass
915 its second argument to the expression evaluator to see whether or not
916 to continue processing. Unfortunately, in this case the value of +i+
917 in the second argument will be substituted once and for all when the
918 `for` command is parsed. If +i+ was 0 before the `for`
919 command was invoked then the second argument of `for` will be +0\<=10+
920 which will always evaluate to 1, even though +i+ eventually
921 becomes greater than 10. In the above case the loop will never
922 terminate. Instead, the expression should be placed in braces:
924 for {set i 1} {$i<=10} {incr i} {...} ** RIGHT **
926 This causes the substitution of 'i'
927 to be delayed; it will be re-done each time the expression is
928 evaluated, which is the desired result.
932 The third major way that strings are interpreted in Tcl is as lists.
933 A list is just a string with a list-like structure
934 consisting of fields separated by white space. For example, the
939 is a list with four elements or fields.
940 Lists have the same basic structure as command strings, except
941 that a newline character in a list is treated as a field separator
942 just like space or tab. Conventions for braces and quotes
943 and backslashes are the same for lists as for commands. For example,
948 is a list with three elements: +a+, +b c+, and +d e {f g h}+.
950 Whenever an element is extracted from a list, the same rules about
951 braces and quotes and backslashes are applied as for commands. Thus in
952 the example above when the third element is extracted from the list,
957 (when the field was extracted, all that happened was to strip off
958 the outermost layer of braces). Command substitution and
959 variable substitution are never
960 made on a list (at least, not by the list-processing commands; the
961 list can always be passed to the Tcl interpreter for evaluation).
963 The Tcl commands `concat`, `foreach`, `lappend`, `lindex`, `linsert`,
964 `list`, `llength`, `lrange`, `lreplace`, `lsearch`, and `lsort` allow
965 you to build lists, extract elements from them, search them, and perform
966 other list-related functions.
968 Advanced list commands include `lrepeat`, `lreverse`, `lmap`, `lassign`, `lset`.
973 A new addition to Tcl 8.5 is the ability to expand a list into separate
974 arguments. Support for this feature is also available in Jim.
976 Consider the following attempt to exec a list:
981 This will attempt to exec a command named "ls -l", which will clearly not
982 work. Typically eval and concat are required to solve this problem, however
983 it can be solved much more easily with +\{*\}+.
987 This will expand the following argument into individual elements and then evaluate
988 the resulting command.
990 Note that the official Tcl syntax is +\{*\}+, however +\{expand\}+ is retained
991 for backward compatibility with experimental versions of this feature.
995 Tcl provides two commands that support string matching using regular
996 expressions, `regexp` and `regsub`, as well as `switch -regexp` and
999 Regular expressions may be implemented one of two ways. Either using the system's C library
1000 POSIX regular expression support, or using the built-in regular expression engine.
1001 The differences between these are described below.
1003 *NOTE* Tcl 7.x and 8.x use perl-style Advanced Regular Expressions (+ARE+).
1005 POSIX Regular Expressions
1006 ~~~~~~~~~~~~~~~~~~~~~~~~~
1007 If the system supports POSIX regular expressions, and UTF-8 support is not enabled,
1008 this support will be used by default. The type of regular expressions supported are
1009 Extended Regular Expressions (+ERE+) rather than Basic Regular Expressions (+BRE+).
1010 See REG_EXTENDED in the documentation.
1012 Using the system-supported POSIX regular expressions will typically
1013 make for the smallest code size, but some features such as UTF-8
1014 and +{backslash}w+, +{backslash}d+, +{backslash}s+ are not supported, and null characters
1015 in strings are not supported.
1017 See regex(3) and regex(7) for full details.
1019 Jim built-in Regular Expressions
1020 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1021 The Jim built-in regular expression engine may be selected with +./configure --with-jim-regexp+
1022 or it will be selected automatically if UTF-8 support is enabled.
1024 This engine supports UTF-8 as well as some +ARE+ features. The differences with both Tcl 7.x/8.x
1025 and POSIX are highlighted below.
1027 1. UTF-8 strings and patterns are both supported
1028 2. Supported character classes: +[:alnum:]+, +[:digit:]+ and +[:space:]+
1029 3. Supported shorthand character classes: +{backslash}w+ = +[:alnum:]+, +{backslash}d+ = +[:digit:],+ +{backslash}s+ = +[:space:]+
1030 4. Character classes apply to ASCII characters only
1031 5. Supported constraint escapes: +{backslash}m+ = +{backslash}<+ = start of word, +{backslash}M+ = +{backslash}>+ = end of word
1032 6. Backslash escapes may be used within regular expressions, such as +{backslash}n+ = newline, +{backslash}uNNNN+ = unicode
1033 7. Support for the +?+ non-greedy quantifier. e.g. +*?+
1034 8. Support for non-capturing parentheses +(?:...)+
1035 9. Jim Tcl considers that both patterns and strings end at a null character (+\x00+)
1039 Each command produces two results: a code and a string. The
1040 code indicates whether the command completed successfully or not,
1041 and the string gives additional information. The valid codes are
1042 defined in jim.h, and are:
1045 This is the normal return code, and indicates that the command completed
1046 successfully. The string gives the command's return value.
1049 Indicates that an error occurred; the string gives a message describing
1053 Indicates that the `return` command has been invoked, and that the
1054 current procedure (or top-level command or `source` command)
1055 should return immediately. The
1056 string gives the return value for the procedure or command.
1059 Indicates that the `break` command has been invoked, so the
1060 innermost loop should abort immediately. The string should always
1064 Indicates that the `continue` command has been invoked, so the
1065 innermost loop should go on to the next iteration. The string
1066 should always be empty.
1069 Indicates that a signal was caught while executing a commands.
1070 The string contains the name of the signal caught.
1071 See the `signal` and `catch` commands.
1074 Indicates that the command called the `exit` command.
1075 The string contains the exit code.
1077 Tcl programmers do not normally need to think about return codes,
1078 since +JIM_OK+ is almost always returned. If anything else is returned
1079 by a command, then the Tcl interpreter immediately stops processing
1080 commands and returns to its caller. If there are several nested
1081 invocations of the Tcl interpreter in progress, then each nested
1082 command will usually return the error to its caller, until eventually
1083 the error is reported to the top-level application code. The
1084 application will then display the error message for the user.
1086 In a few cases, some commands will handle certain `error` conditions
1087 themselves and not return them upwards. For example, the `for`
1088 command checks for the +JIM_BREAK+ code; if it occurs, then `for`
1089 stops executing the body of the loop and returns +JIM_OK+ to its
1090 caller. The `for` command also handles +JIM_CONTINUE+ codes and the
1091 procedure interpreter handles +JIM_RETURN+ codes. The `catch`
1092 command allows Tcl programs to catch errors and handle them without
1093 aborting command interpretation any further.
1095 The `info returncodes` command may be used to programmatically map between
1096 return codes and names.
1100 Tcl allows you to extend the command interface by defining
1101 procedures. A Tcl procedure can be invoked just like any other Tcl
1102 command (it has a name and it receives one or more arguments).
1103 The only difference is that its body isn't a piece of C code linked
1104 into the program; it is a string containing one or more other
1107 The `proc` command is used to create a new Tcl command procedure:
1109 +*proc* 'name arglist ?statics? body'+
1111 The new command is named +'name'+, and it replaces any existing command
1112 there may have been by that name. Whenever the new command is
1113 invoked, the contents of +'body'+ will be executed by the Tcl
1116 +'arglist'+ specifies the formal arguments to the procedure.
1117 It consists of a list, possibly empty, of the following
1118 argument specifiers:
1121 Required Argument - A simple argument name.
1124 Optional Argument - A two-element list consisting of the
1125 argument name, followed by the default value, which will
1126 be used if the corresponding argument is not supplied.
1129 Reference Argument - The caller is expected to pass the name of
1130 an existing variable. An implicit `upvar 1 'origname' 'name'` is done
1131 to make the variable available in the proc scope.
1134 Variable Argument - The special name +'args'+, which is
1135 assigned all remaining arguments (including none) as a list. The
1136 variable argument may only be specified once. Note that
1137 the syntax +args newname+ may be used to retain the special
1138 behaviour of +'args'+ with a different local name. In this case,
1139 the variable is named +'newname'+ rather than +'args'+.
1141 When the command is invoked, a local variable will be created for each of
1142 the formal arguments to the procedure; its value will be the value
1143 of corresponding argument in the invoking command or the argument's
1146 Arguments with default values need not be specified in a procedure
1147 invocation. However, there must be enough actual arguments for all
1148 required arguments, and there must not be any extra actual arguments
1149 (unless the Variable Argument is specified).
1151 Actual arguments are assigned to formal arguments as in left-to-right
1152 order with the following precedence.
1154 1. Required Arguments (including Reference Arguments)
1155 2. Optional Arguments
1156 3. Variable Argument
1158 The following example illustrates precedence. Assume a procedure declaration:
1160 proc p {{a A} args b {c C} d} {...}
1162 This procedure requires at least two arguments, but can accept an unlimited number.
1163 The following table shows how various numbers of arguments are assigned.
1164 Values marked as +-+ are assigned the default value.
1166 [width="40%",frame="topbot",options="header"]
1168 |Number of arguments|a|args|b|c|d
1176 When +'body'+ is being executed, variable names normally refer to local
1177 variables, which are created automatically when referenced and deleted
1178 when the procedure returns. One local variable is automatically created
1179 for each of the procedure's arguments. Global variables can be
1180 accessed by invoking the `global` command or via the +::+ prefix.
1184 In addition to procedure arguments, Jim procedures may declare static variables.
1185 These variables scoped to the procedure and initialised at procedure definition.
1186 Either from the static variable definition, or from the enclosing scope.
1188 Consider the following example:
1191 jim> proc a {} {a {b 2}} {
1203 The static variable +'a'+ has no initialiser, so it is initialised from
1204 the enclosing scope with the value 1. (Note that it is an error if there
1205 is no variable with the same name in the enclosing scope). However +'b'+
1206 has an initialiser, so it is initialised to 2.
1208 Unlike a local variable, the value of a static variable is retained across
1209 invocations of the procedure.
1211 See the `proc` command for information on how to define procedures
1212 and what happens when they are invoked. See also NAMESPACES.
1214 VARIABLES - SCALARS AND ARRAYS
1215 ------------------------------
1216 Tcl allows the definition of variables and the use of their values
1217 either through '$'-style variable substitution, the `set`
1218 command, or a few other mechanisms.
1220 Variables need not be declared: a new variable will automatically
1221 be created each time a new variable name is used.
1223 Tcl supports two types of variables: scalars and arrays.
1224 A scalar variable has a single value, whereas an array variable
1225 can have any number of elements, each with a name (called
1226 its 'index') and a value.
1228 Array indexes may be arbitrary strings; they need not be numeric.
1229 Parentheses are used refer to array elements in Tcl commands.
1230 For example, the command
1234 will modify the element of 'x' whose index is 'first'
1235 so that its new value is '44'.
1237 Two-dimensional arrays can be simulated in Tcl by using indexes
1238 that contain multiple concatenated values.
1239 For example, the commands
1244 set the elements of 'a' whose indexes are '2,3' and '3,6'.
1246 In general, array elements may be used anywhere in Tcl that scalar
1247 variables may be used.
1249 If an array is defined with a particular name, then there may
1250 not be a scalar variable with the same name.
1252 Similarly, if there is a scalar variable with a particular
1253 name then it is not possible to make array references to the
1256 To convert a scalar variable to an array or vice versa, remove
1257 the existing variable with the `unset` command.
1259 The `array` command provides several features for dealing
1260 with arrays, such as querying the names of all the elements of
1261 the array and converting between an array and a list.
1263 Variables may be either global or local. If a variable
1264 name is used when a procedure isn't being executed, then it
1265 automatically refers to a global variable. Variable names used
1266 within a procedure normally refer to local variables associated with that
1267 invocation of the procedure. Local variables are deleted whenever
1268 a procedure exits. Either `global` command may be used to request
1269 that a name refer to a global variable for the duration of the current
1270 procedure (this is somewhat analogous to 'extern' in C), or the variable
1271 may be explicitly scoped with the +::+ prefix. For example
1287 ARRAYS AS LISTS IN JIM
1288 ----------------------
1289 Unlike Tcl, Jim can automatically convert between a list (with an even
1290 number of elements) and an array value. This is similar to the way Tcl
1291 can convert between a string and a list.
1302 Thus `array set` is equivalent to `set` when the variable does not
1305 The reverse is also true where an array will be converted into
1308 set a(1) one; set a(2) two
1317 Tcl 8.5 introduced the dict command, and Jim Tcl has added a version
1318 of this command. Dictionaries provide efficient access to key-value
1319 pairs, just like arrays, but dictionaries are pure values. This
1320 means that you can pass them to a procedure just as a list or a
1321 string. Tcl dictionaries are therefore much more like Tcl lists,
1322 except that they represent a mapping from keys to values, rather
1323 than an ordered sequence.
1325 You can nest dictionaries, so that the value for a particular key
1326 consists of another dictionary. That way you can elegantly build
1327 complicated data structures, such as hierarchical databases. You
1328 can also combine dictionaries with other Tcl data structures. For
1329 instance, you can build a list of dictionaries that themselves
1332 Dictionaries are values that contain an efficient, order-preserving
1333 mapping from arbitrary keys to arbitrary values. Each key in the
1334 dictionary maps to a single value. They have a textual format that
1335 is exactly that of any list with an even number of elements, with
1336 each mapping in the dictionary being represented as two items in
1337 the list. When a command takes a dictionary and produces a new
1338 dictionary based on it (either returning it or writing it back into
1339 the variable that the starting dictionary was read from) the new
1340 dictionary will have the same order of keys, modulo any deleted
1341 keys and with new keys added on to the end. When a string is
1342 interpreted as a dictionary and it would otherwise have duplicate
1343 keys, only the last value for a particular key is used; the others
1344 are ignored, meaning that, "apple banana" and "apple carrot apple
1345 banana" are equivalent dictionaries (with different string
1348 Note that in Jim, arrays are implemented as dictionaries.
1349 Thus automatic conversion between lists and dictionaries applies
1350 as it does for arrays.
1352 jim> dict set a 1 one
1354 jim> dict set a 2 two
1360 jim> dict set a 3 T three
1361 1 one 2 two 3 {T three}
1363 See the `dict` command for more details.
1367 Tcl added namespaces as a mechanism avoiding name clashes, especially in applications
1368 including a number of 3rd party components. While there is less need for namespaces
1369 in Jim Tcl (which does not strive to support large applications), it is convenient to
1370 provide a subset of the support for namespaces to easy porting code from Tcl.
1372 Jim Tcl currently supports "light-weight" namespaces which should be adequate for most
1373 purposes. This feature is currently experimental. See README.namespaces for more information
1374 and the documentation of the `namespace` command.
1376 GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION
1377 -----------------------------------------------
1378 Unlike Tcl, Jim has some sophisticated support for functional programming.
1379 These are described briefly below.
1381 More information may be found at http://wiki.tcl.tk/13847
1385 A reference can be thought of as holding a value with one level of indirection,
1386 where the value may be garbage collected when unreferenced.
1387 Consider the following example:
1389 jim> set r [ref "One String" test]
1390 <reference.<test___>.00000000000000000000>
1394 The operation `ref` creates a references to the value specified by the
1395 first argument. (The second argument is a "type" used for documentation purposes).
1397 The operation `getref` is the dereferencing operation which retrieves the value
1398 stored in the reference.
1400 jim> setref $r "New String"
1405 The operation `setref` replaces the value stored by the reference. If the old value
1406 is no longer accessible by any reference, it will eventually be automatically be garbage
1411 Normally, all values in Tcl are passed by value. As such values are copied and released
1412 automatically as necessary.
1414 With the introduction of references, it is possible to create values whose lifetime
1415 transcend their scope. To support this, case, the Jim system will periodically identify
1416 and discard objects which are no longer accessible by any reference.
1418 The `collect` command may be used to force garbage collection. Consider a reference created
1421 jim> proc f {ref value} { puts "Finaliser called for $ref,$value" }
1422 jim> set r [ref "One String" test f]
1423 <reference.<test___>.00000000000
1428 Finaliser called for <reference.<test___>.00000000000,One String
1431 Note that once the reference, 'r', was modified so that it no longer
1432 contained a reference to the value, the garbage collector discarded
1433 the value (after calling the finalizer).
1435 The finalizer for a reference may be examined or changed with the `finalize` command
1439 jim> finalize $r newf
1444 Jim provides a garbage collected `lambda` function. This is a procedure
1445 which is able to create an anonymous procedure. Consider:
1447 jim> set f [lambda {a} {{x 0}} { incr x $a }]
1454 This create an anonymous procedure (with the name stored in 'f'), with a static variable
1455 which is incremented by the supplied value and the result returned.
1457 Once the procedure name is no longer accessible, it will automatically be deleted
1458 when the garbage collector runs.
1460 The procedure may also be delete immediately by renaming it "". e.g.
1466 If Jim is built with UTF-8 support enabled (configure --enable-utf),
1467 then most string-related commands become UTF-8 aware. These include,
1468 but are not limited to, `string match`, `split`, `glob`, `scan` and
1471 UTF-8 encoding has many advantages, but one of the complications is that
1472 characters can take a variable number of bytes. Thus the addition of
1473 `string bytelength` which returns the number of bytes in a string,
1474 while `string length` returns the number of characters.
1476 If UTF-8 support is not enabled, all commands treat bytes as characters
1477 and `string bytelength` returns the same value as `string length`.
1479 Note that even if UTF-8 support is not enabled, the +{backslash}uNNNN+ and related syntax
1480 is still available to embed UTF-8 sequences.
1482 Jim Tcl supports all currently defined unicode codepoints. That is 21 bits, up to +'U+1FFFFF'.
1486 Commands such as `string match`, `lsearch -glob`, `array names` and others use string
1487 pattern matching rules. These commands support UTF-8. For example:
1489 string match a\[\ua0-\ubf\]b "a\u00a3b"
1493 +format %c+ allows a unicode codepoint to be be encoded. For example, the following will return
1494 a string with two bytes and one character. The same as +{backslash}ub5+
1498 `format` respects widths as character widths, not byte widths. For example, the following will
1499 return a string with three characters, not three bytes.
1501 format %.3s \ub5\ub6\ub7\ub8
1503 Similarly, +scan ... %c+ allows a UTF-8 to be decoded to a unicode codepoint. The following will set
1504 +'a'+ to 181 (0xb5) and +'b'+ to 65 (0x41).
1506 scan \u00b5A %c%c a b
1508 `scan %s` will also accept a character class, including unicode ranges.
1512 `string is` has *not* been extended to classify UTF-8 characters. Therefore, the following
1513 will return 0, even though the string may be considered to be alphabetic.
1515 string is alpha \ub5Test
1517 This does not affect the string classes 'ascii', 'control', 'digit', 'double', 'integer' or 'xdigit'.
1519 Case Mapping and Conversion
1520 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
1521 Jim provides a simplified unicode case mapping. This means that case conversion
1522 and comparison will not increase or decrease the number of characters in a string.
1523 (Although it may change the number of bytes).
1525 `string toupper` will convert any lowercase letters to their uppercase equivalent.
1526 Any character which is not a letter or has no uppercase equivalent is left unchanged.
1527 Similarly for `string tolower` and `string totitle`.
1529 Commands which perform case insensitive matches, such as `string compare -nocase`
1530 and `lsearch -nocase` fold both strings to uppercase before comparison.
1532 Invalid UTF-8 Sequences
1533 ~~~~~~~~~~~~~~~~~~~~~~~
1534 Some UTF-8 character sequences are invalid, such as those beginning with '0xff',
1535 those which represent character sequences longer than 3 bytes (greater than U+FFFF),
1536 and those which end prematurely, such as a lone '0xc2'.
1538 In these situations, the offending bytes are treated as single characters. For example,
1539 the following returns 2.
1541 string bytelength \xff\xff
1545 If UTF-8 support is enabled, the built-in regular expression engine will be
1546 selected which supports UTF-8 strings and patterns.
1548 See REGULAR EXPRESSIONS
1552 The Tcl library provides the following built-in commands, which will
1553 be available in any application using Tcl. In addition to these
1554 built-in commands, there may be additional commands defined by each
1555 application, plus commands defined as Tcl procedures.
1557 In the command syntax descriptions below, words in +*boldface*+ are
1558 literals that you type verbatim to Tcl.
1560 Words in +'italics'+ are meta-symbols; they serve as names for any of
1561 a range of values that you can type.
1563 Optional arguments or groups of arguments are indicated by enclosing them
1564 in +?question-marks?+.
1566 Ellipses (+\...+) indicate that any number of additional
1567 arguments or groups of arguments may appear, in the same format
1568 as the preceding argument(s).
1579 Delivers the +SIGALRM+ signal to the process after the given
1580 number of seconds. If the platform supports 'ualarm(3)' then
1581 the argument may be a floating point value. Otherwise it must
1584 Note that unless a signal handler for +SIGALRM+ has been installed
1585 (see `signal`), the process will exit on this signal.
1589 +*alias* 'name args\...'+
1591 Creates a single word alias (command) for one or more words. For example,
1592 the following creates an alias for the command `info exists`.
1599 `alias` returns +'name'+, allowing it to be used with `local`.
1601 See also `proc`, `curry`, `lambda`, `local`, `info alias`, `exists -alias`
1605 +*append* 'varName value ?value value ...?'+
1607 Append all of the +'value'+ arguments to the current value
1608 of variable +'varName'+. If +'varName'+ doesn't exist,
1609 it is given a value equal to the concatenation of all the
1610 +'value'+ arguments.
1612 This command provides an efficient way to build up long
1613 variables incrementally.
1614 For example, "`append a $b`" is much more efficient than
1615 "`set a $a$b`" if +$a+ is long.
1619 +*apply* 'lambdaExpr ?arg1 arg2 \...?'+
1621 The command `apply` provides for anonymous procedure calls,
1622 similar to `lambda`, but without command name being created, even temporarily.
1624 The function +'lambdaExpr'+ is a two element list +{args body}+
1625 or a three element list +{args body namespace}+. The first element
1626 args specifies the formal arguments, in the same form as the `proc` and `lambda` commands.
1630 +*array* 'option arrayName ?arg\...?'+
1632 This command performs one of several operations on the
1633 variable given by +'arrayName'+.
1635 Note that in general, if the named array does not exist, the +'array'+ command behaves
1636 as though the array exists but is empty.
1638 The +'option'+ argument determines what action is carried out by the
1639 command. The legal +'options'+ (which may be abbreviated) are:
1641 +*array exists* 'arrayName'+::
1642 Returns 1 if arrayName is an array variable, 0 if there is
1643 no variable by that name. This command is essentially
1644 identical to `info exists`
1646 +*array get* 'arrayName ?pattern?'+::
1647 Returns a list containing pairs of elements. The first
1648 element in each pair is the name of an element in arrayName
1649 and the second element of each pair is the value of the
1650 array element. The order of the pairs is undefined. If
1651 pattern is not specified, then all of the elements of the
1652 array are included in the result. If pattern is specified,
1653 then only those elements whose names match pattern (using
1654 the matching rules of string match) are included. If arrayName
1655 isn't the name of an array variable, or if the array contains
1656 no elements, then an empty list is returned.
1658 +*array names* 'arrayName ?pattern?'+::
1659 Returns a list containing the names of all of the elements
1660 in the array that match pattern. If pattern is omitted then
1661 the command returns all of the element names in the array.
1662 If pattern is specified, then only those elements whose
1663 names match pattern (using the matching rules of string
1664 match) are included. If there are no (matching) elements
1665 in the array, or if arrayName isn't the name of an array
1666 variable, then an empty string is returned.
1668 +*array set* 'arrayName list'+::
1669 Sets the values of one or more elements in arrayName. list
1670 must have a form like that returned by array get, consisting
1671 of an even number of elements. Each odd-numbered element
1672 in list is treated as an element name within arrayName, and
1673 the following element in list is used as a new value for
1674 that array element. If the variable arrayName does not
1675 already exist and list is empty, arrayName is created with
1676 an empty array value.
1678 +*array size* 'arrayName'+::
1679 Returns the number of elements in the array. If arrayName
1680 isn't the name of an array then 0 is returned.
1682 +*array unset* 'arrayName ?pattern?'+::
1683 Unsets all of the elements in the array that match pattern
1684 (using the matching rules of string match). If arrayName
1685 isn't the name of an array variable or there are no matching
1686 elements in the array, no error will be raised. If pattern
1687 is omitted and arrayName is an array variable, then the
1688 command unsets the entire array. The command always returns
1695 This command may be invoked only inside the body of a loop command
1696 such as `for` or `foreach` or `while`. It returns a +JIM_BREAK+ code
1697 to signal the innermost containing loop command to return immediately.
1701 +*case* 'string' ?in? 'patList body ?patList body ...?'+
1703 +*case* 'string' ?in? {'patList body ?patList body ...?'}+
1705 *Note* that the `switch` command should generally be preferred unless compatibility
1706 with Tcl 6.x is desired.
1708 Match +'string'+ against each of the +'patList'+ arguments
1709 in order. If one matches, then evaluate the following +'body'+ argument
1710 by passing it recursively to the Tcl interpreter, and return the result
1711 of that evaluation. Each +'patList'+ argument consists of a single
1712 pattern or list of patterns. Each pattern may contain any of the wild-cards
1713 described under `string match`.
1715 If a +'patList'+ argument is +default+, the corresponding body will be
1716 evaluated if no +'patList'+ matches +'string'+. If no +'patList'+ argument
1717 matches +'string'+ and no default is given, then the `case` command returns
1720 Two syntaxes are provided.
1722 The first uses a separate argument for each of the patterns and commands;
1723 this form is convenient if substitutions are desired on some of the
1724 patterns or commands.
1726 The second form places all of the patterns and commands together into
1727 a single argument; the argument must have proper list structure, with
1728 the elements of the list being the patterns and commands.
1730 The second form makes it easy to construct multi-line case commands,
1731 since the braces around the whole list make it unnecessary to include a
1732 backslash at the end of each line.
1734 Since the +'patList'+ arguments are in braces in the second form,
1735 no command or variable substitutions are performed on them; this makes
1736 the behaviour of the second form different than the first form in some
1739 Below are some examples of `case` commands:
1741 case abc in {a b} {format 1} default {format 2} a* {format 3}
1751 will return '1', and
1766 +*catch* ?-?no?'code \...'? ?--? 'command ?resultVarName? ?optionsVarName?'+
1768 The `catch` command may be used to prevent errors from aborting
1769 command interpretation. `catch` evaluates +'command'+, and returns a
1770 +JIM_OK+ code, regardless of any errors that might occur while
1771 executing +'command'+ (with the possible exception of +JIM_SIGNAL+ -
1774 The return value from `catch` is a decimal string giving the code
1775 returned by the Tcl interpreter after executing +'command'+. This
1776 will be '0' (+JIM_OK+) if there were no errors in +'command'+; otherwise
1777 it will have a non-zero value corresponding to one of the exceptional
1778 return codes (see jim.h for the definitions of code values, or the
1779 `info returncodes` command).
1781 If the +'resultVarName'+ argument is given, then it gives the name
1782 of a variable; `catch` will set the value of the variable to the
1783 string returned from +'command'+ (either a result or an error message).
1785 If the +'optionsVarName'+ argument is given, then it gives the name
1786 of a variable; `catch` will set the value of the variable to a
1787 dictionary. For any return code other than +JIM_RETURN+, the value
1788 for the key +-code+ will be set to the return code. For +JIM_RETURN+
1789 it will be set to the code given in `return -code`. Additionally,
1790 for the return code +JIM_ERR+, the value of the key +-errorinfo+
1791 will contain the current stack trace (the same result as `info stacktrace`),
1792 the value of the key +-errorcode+ will contain the
1793 same value as the global variable $::errorCode, and the value of
1794 the key +-level+ will be the current return level (see `return -level`).
1795 This can be useful to rethrow an error:
1797 if {[catch {...} msg opts]} {
1798 ...maybe do something with the error...
1800 return {*}$opts $msg
1803 Normally `catch` will +'not'+ catch any of the codes +JIM_EXIT+, +JIM_EVAL+ or +JIM_SIGNAL+.
1804 The set of codes which will be caught may be modified by specifying the one more codes before
1807 e.g. To catch +JIM_EXIT+ but not +JIM_BREAK+ or +JIM_CONTINUE+
1809 catch -exit -nobreak -nocontinue -- { ... }
1811 The use of +--+ is optional. It signifies that no more return code options follow.
1813 Note that if a signal marked as `signal handle` is caught with `catch -signal`, the return value
1814 (stored in +'resultVarName'+) is name of the signal caught.
1820 Change the current working directory to +'dirName'+.
1822 Returns an empty string.
1824 This command can potentially be disruptive to an application, so it may
1825 be removed in some applications.
1830 Returns the current time as seconds since the epoch.
1833 Returns the current time in `clicks'.
1835 +*clock microseconds*+::
1836 Returns the current time in microseconds.
1838 +*clock milliseconds*+::
1839 Returns the current time in milliseconds.
1841 +*clock format* 'seconds' ?*-format* 'format?'+::
1842 Format the given time (seconds since the epoch) according to the given
1843 format. See strftime(3) for supported formats.
1844 If no format is supplied, "%c" is used.
1846 +*clock scan* 'str' *-format* 'format'+::
1847 Scan the given time string using the given format string.
1848 See strptime(3) for supported formats.
1856 Closes the file given by +'fileId'+.
1857 +'fileId'+ must be the return value from a previous invocation
1858 of the `open` command; after this command, it should not be
1865 Normally reference garbage collection is automatically performed periodically.
1866 However it may be run immediately with the `collect` command.
1868 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
1872 +*concat* 'arg ?arg \...?'+
1874 This command treats each argument as a list and concatenates them
1875 into a single list. It permits any number of arguments. For example,
1878 concat a b {c d e} {f {g h}}
1890 This command may be invoked only inside the body of a loop command such
1891 as `for` or `foreach` or `while`. It returns a +JIM_CONTINUE+ code to
1892 signal the innermost containing loop command to skip the remainder of
1893 the loop's body but continue with the next iteration of the loop.
1897 +*alias* 'args\...'+
1899 Similar to `alias` except it creates an anonymous procedure (lambda) instead of
1902 the following creates a local, unnamed alias for the command `info exists`.
1904 set e [local curry info exists]
1909 `curry` returns the name of the procedure.
1911 See also `proc`, `alias`, `lambda`, `local`.
1915 +*dict* 'option ?arg\...?'+
1917 Performs one of several operations on dictionary values.
1919 The +'option'+ argument determines what action is carried out by the
1920 command. The legal +'options'+ are:
1922 +*dict create* '?key value \...?'+::
1923 Create and return a new dictionary value that contains each of
1924 the key/value mappings listed as arguments (keys and values
1925 alternating, with each key being followed by its associated
1928 +*dict exists* 'dictionary key ?key \...?'+::
1929 Returns a boolean value indicating whether the given key (or path
1930 of keys through a set of nested dictionaries) exists in the given
1931 dictionary value. This returns a true value exactly when `dict get`
1932 on that path will succeed.
1934 +*dict get* 'dictionary ?key \...?'+::
1935 Given a dictionary value (first argument) and a key (second argument),
1936 this will retrieve the value for that key. Where several keys are
1937 supplied, the behaviour of the command shall be as if the result
1938 of "`dict get $dictVal $key`" was passed as the first argument to
1939 dict get with the remaining arguments as second (and possibly
1940 subsequent) arguments. This facilitates lookups in nested dictionaries.
1941 If no keys are provided, dict would return a list containing pairs
1942 of elements in a manner similar to array get. That is, the first
1943 element of each pair would be the key and the second element would
1944 be the value for that key. It is an error to attempt to retrieve
1945 a value for a key that is not present in the dictionary.
1947 +*dict keys* 'dictionary ?pattern?'+::
1948 Returns a list of the keys in the dictionary.
1949 If pattern is specified, then only those keys whose
1950 names match +'pattern'+ (using the matching rules of string
1951 match) are included.
1953 +*dict merge* ?'dictionary \...'?+::
1954 Return a dictionary that contains the contents of each of the
1955 +'dictionary'+ arguments. Where two (or more) dictionaries
1956 contain a mapping for the same key, the resulting dictionary
1957 maps that key to the value according to the last dictionary on
1958 the command line containing a mapping for that key.
1960 +*dict set* 'dictionaryName key ?key \...? value'+::
1961 This operation takes the +'name'+ of a variable containing a dictionary
1962 value and places an updated dictionary value in that variable
1963 containing a mapping from the given key to the given value. When
1964 multiple keys are present, this operation creates or updates a chain
1965 of nested dictionaries.
1967 +*dict size* 'dictionary'+::
1968 Return the number of key/value mappings in the given dictionary value.
1970 +*dict unset* 'dictionaryName key ?key \...? value'+::
1971 This operation (the companion to `dict set`) takes the name of a
1972 variable containing a dictionary value and places an updated
1973 dictionary value in that variable that does not contain a mapping
1974 for the given key. Where multiple keys are present, this describes
1975 a path through nested dictionaries to the mapping to remove. At
1976 least one key must be specified, but the last key on the key-path
1977 need not exist. All other components on the path must exist.
1979 +*dict with* 'dictionaryName key ?key \...? script'+::
1980 Execute the Tcl script in +'script'+ with the value for each
1981 key in +'dictionaryName'+ mapped to a variable with the same
1982 name. Where one or more keys are given, these indicate a chain
1983 of nested dictionaries, with the innermost dictionary being the
1984 one opened out for the execution of body. Making +'dictionaryName'+
1985 unreadable will make the updates to the dictionary be discarded,
1986 and this also happens if the contents of +'dictionaryName'+ are
1987 adjusted so that the chain of dictionaries no longer exists.
1988 The result of `dict with` is (unless some kind of error occurs)
1989 the result of the evaluation of body.
1991 The variables are mapped in the scope enclosing the `dict with`;
1992 it is recommended that this command only be used in a local
1993 scope (procedure). Because of this, the variables set by
1994 `dict with` will continue to exist after the command finishes (unless
1995 explicitly unset). Note that changes to the contents of +'dictionaryName'+
1996 only happen when +'script'+ terminates.
1998 +*dict for, values, incr, append, lappend, update, info, replace*+ to be documented...
2002 +*env* '?name? ?default?'+
2004 If +'name'+ is supplied, returns the value of +'name'+ from the initial
2005 environment (see getenv(3)). An error is returned if +'name'+ does not
2006 exist in the environment, unless +'default'+ is supplied - in which case
2007 that value is returned instead.
2009 If no arguments are supplied, returns a list of all environment variables
2010 and their values as +{name value \...}+
2012 See also the global variable +::env+
2020 Returns 1 if an end-of-file condition has occurred on +'fileId'+,
2023 +'fileId'+ must have been the return value from a previous call to `open`,
2024 or it may be +stdin+, +stdout+, or +stderr+ to refer to one of the
2025 standard I/O channels.
2029 +*error* 'message ?stacktrace?'+
2031 Returns a +JIM_ERR+ code, which causes command interpretation to be
2032 unwound. +'message'+ is a string that is returned to the application
2033 to indicate what went wrong.
2035 If the +'stacktrace'+ argument is provided and is non-empty,
2036 it is used to initialize the stacktrace.
2038 This feature is most useful in conjunction with the `catch` command:
2039 if a caught error cannot be handled successfully, +'stacktrace'+ can be used
2040 to return a stack trace reflecting the original point of occurrence
2045 error $errMsg [info stacktrace]
2047 See also `errorInfo`, `info stacktrace`, `catch` and `return`
2051 +*errorInfo* 'error ?stacktrace?'+
2053 Returns a human-readable representation of the given error message and stack trace.
2056 if {[catch {...} error]} {
2057 puts stderr [errorInfo $error [info stacktrace]]
2065 +*eval* 'arg ?arg\...?'+
2067 `eval` takes one or more arguments, which together comprise a Tcl
2068 command (or collection of Tcl commands separated by newlines in the
2069 usual way). `eval` concatenates all its arguments in the same
2070 fashion as the `concat` command, passes the concatenated string to the
2071 Tcl interpreter recursively, and returns the result of that
2072 evaluation (or any error generated by it).
2076 +*exec* 'arg ?arg\...?'+
2078 This command treats its arguments as the specification
2079 of one or more UNIX commands to execute as subprocesses.
2080 The commands take the form of a standard shell pipeline;
2081 +|+ arguments separate commands in the
2082 pipeline and cause standard output of the preceding command
2083 to be piped into standard input of the next command (or +|&+ for
2084 both standard output and standard error).
2086 Under normal conditions the result of the `exec` command
2087 consists of the standard output produced by the last command
2088 in the pipeline followed by the standard error output.
2090 If any of the commands writes to its standard error file,
2091 then this will be included in the result after the standard output
2092 of the last command.
2094 Note that unlike Tcl, data written to standard error does not cause
2095 `exec` to return an error.
2097 If any of the commands in the pipeline exit abnormally or
2098 are killed or suspended, then `exec` will return an error.
2099 If no standard error output was produced, or is redirected,
2100 the error message will include the normal result, as above,
2101 followed by error messages describing the abnormal terminations.
2103 If any standard error output was produced, these abnormal termination
2104 messages are suppressed.
2106 If the last character of the result or error message
2107 is a newline then that character is deleted from the result
2108 or error message for consistency with normal
2111 An +'arg'+ may have one of the following special forms:
2114 The standard output of the last command in the pipeline
2115 is redirected to the file. In this situation `exec`
2116 will normally return an empty string.
2119 As above, but append to the file.
2122 The standard output of the last command in the pipeline is
2123 redirected to the given (writable) file descriptor (e.g. stdout,
2124 stderr, or the result of `open`). In this situation `exec`
2125 will normally return an empty string.
2128 The standard error of the last command in the pipeline
2129 is redirected to the file.
2132 As above, but append to the file.
2135 The standard error of the last command in the pipeline is
2136 redirected to the given (writable) file descriptor.
2139 The standard error of the last command in the pipeline is
2140 redirected to the same file descriptor as the standard output.
2143 Both the standard output and standard error of the last command
2144 in the pipeline is redirected to the file.
2147 As above, but append to the file.
2150 The standard input of the first command in the pipeline
2151 is taken from the file.
2154 The standard input of the first command is taken as the
2155 given immediate value.
2158 The standard input of the first command in the pipeline
2159 is taken from the given (readable) file descriptor.
2161 If there is no redirection of standard input, standard error
2162 or standard output, these are connected to the corresponding
2163 input or output of the application.
2165 If the last +'arg'+ is +&+ then the command will be
2166 executed in background.
2167 In this case the standard output from the last command
2168 in the pipeline will
2169 go to the application's standard output unless
2170 redirected in the command, and error output from all
2171 the commands in the pipeline will go to the application's
2172 standard error file. The return value of exec in this case
2173 is a list of process ids (pids) in the pipeline.
2175 Each +'arg'+ becomes one word for a command, except for
2176 +|+, +<+, +<<+, +>+, and +&+ arguments, and the
2177 arguments that follow +<+, +<<+, and +>+.
2179 The first word in each command is taken as the command name;
2180 the directories in the PATH environment variable are searched for
2181 an executable by the given name.
2183 No `glob` expansion or other shell-like substitutions
2184 are performed on the arguments to commands.
2186 If the command fails, the global $::errorCode (and the -errorcode
2187 option in `catch`) will be set to a list, as follows:
2189 +*CHILDKILLED* 'pid sigName msg'+::
2190 This format is used when a child process has been killed
2191 because of a signal. The pid element will be the process's
2192 identifier (in decimal). The sigName element will be the
2193 symbolic name of the signal that caused the process to
2194 terminate; it will be one of the names from the include
2195 file signal.h, such as SIGPIPE. The msg element will be a
2196 short human-readable message describing the signal, such
2197 as "write on pipe with no readers" for SIGPIPE.
2199 +*CHILDSUSP* 'pid sigName msg'+::
2200 This format is used when a child process has been suspended
2201 because of a signal. The pid element will be the process's
2202 identifier, in decimal. The sigName element will be the
2203 symbolic name of the signal that caused the process to
2204 suspend; this will be one of the names from the include
2205 file signal.h, such as SIGTTIN. The msg element will be a
2206 short human-readable message describing the signal, such
2207 as "background tty read" for SIGTTIN.
2209 +*CHILDSTATUS* 'pid code'+::
2210 This format is used when a child process has exited with a
2211 non-zero exit status. The pid element will be the process's
2212 identifier (in decimal) and the code element will be the
2213 exit code returned by the process (also in decimal).
2215 The environment for the executed command is set from $::env (unless
2216 this variable is unset, in which case the original environment is used).
2220 +*exists ?-var|-proc|-command|-alias?* 'name'+
2222 Checks the existence of the given variable, procedure, command
2223 or alias respectively and returns 1 if it exists or 0 if not. This command
2224 provides a more simplified/convenient version of `info exists`,
2225 `info procs` and `info commands`.
2227 If the type is omitted, a type of '-var' is used. The type may be abbreviated.
2231 +*exit* '?returnCode?'+
2233 Terminate the process, returning +'returnCode'+ to the
2234 parent as the exit status.
2236 If +'returnCode'+ isn't specified then it defaults
2239 Note that exit can be caught with `catch`.
2245 Calls the expression processor to evaluate +'arg'+, and returns
2246 the result as a string. See the section EXPRESSIONS above.
2248 Note that Jim supports a shorthand syntax for `expr` as +$(\...)+
2249 The following two are identical.
2251 set x [expr {3 * 2 + 1}]
2256 +*file* 'option name ?arg\...?'+
2258 Operate on a file or a file name. +'name'+ is the name of a file.
2260 +'option'+ indicates what to do with the file name. Any unique
2261 abbreviation for +'option'+ is acceptable. The valid options are:
2263 +*file atime* 'name'+::
2264 Return a decimal string giving the time at which file +'name'+
2265 was last accessed. The time is measured in the standard UNIX
2266 fashion as seconds from a fixed starting time (often January 1, 1970).
2267 If the file doesn't exist or its access time cannot be queried then an
2270 +*file copy ?-force?* 'source target'+::
2271 Copies file +'source'+ to file +'target'+. The source file must exist.
2272 The target file must not exist, unless +-force+ is specified.
2274 +*file delete ?-force? ?--?* 'name\...'+::
2275 Deletes file or directory +'name'+. If the file or directory doesn't exist, nothing happens.
2276 If it can't be deleted, an error is generated. Non-empty directories will not be deleted
2277 unless the +-force+ options is given. In this case no errors will be generated, even
2278 if the file/directory can't be deleted. Use +'--'+ if there is any possibility of
2279 the first name being +'-force'+.
2281 +*file dirname* 'name'+::
2282 Return all of the characters in +'name'+ up to but not including
2283 the last slash character. If there are no slashes in +'name'+
2284 then return +.+ (a single dot). If the last slash in +'name'+ is its first
2285 character, then return +/+.
2287 +*file executable* 'name'+::
2288 Return '1' if file +'name'+ is executable by
2289 the current user, '0' otherwise.
2291 +*file exists* 'name'+::
2292 Return '1' if file +'name'+ exists and the current user has
2293 search privileges for the directories leading to it, '0' otherwise.
2295 +*file extension* 'name'+::
2296 Return all of the characters in +'name'+ after and including the
2297 last dot in +'name'+. If there is no dot in +'name'+ then return
2300 +*file isdirectory* 'name'+::
2301 Return '1' if file +'name'+ is a directory,
2304 +*file isfile* 'name'+::
2305 Return '1' if file +'name'+ is a regular file,
2308 +*file join* 'arg\...'+::
2309 Joins multiple path components. Note that if any components is
2310 an absolute path, the preceding components are ignored.
2311 Thus +"`file` join /tmp /root"+ returns +"/root"+.
2313 +*file link* ?*-hard|-symbolic*? 'newname target'+::
2314 Creates a hard link (default) or symbolic link from +'newname'+ to +'target'+.
2315 Note that the sense of this command is the opposite of `file rename` and `file copy`
2316 and also of `ln`, but this is compatible with Tcl.
2317 An error is returned if +'target'+ doesn't exist or +'newname'+ already exists.
2319 +*file lstat* 'name varName'+::
2320 Same as 'stat' option (see below) except uses the +'lstat'+
2321 kernel call instead of +'stat'+. This means that if +'name'+
2322 refers to a symbolic link the information returned in +'varName'+
2323 is for the link rather than the file it refers to. On systems that
2324 don't support symbolic links this option behaves exactly the same
2325 as the 'stat' option.
2327 +*file mkdir* 'dir1 ?dir2\...?'+::
2328 Creates each directory specified. For each pathname +'dir'+ specified,
2329 this command will create all non-existing parent directories
2330 as well as +'dir'+ itself. If an existing directory is specified,
2331 then no action is taken and no error is returned. Trying to
2332 overwrite an existing file with a directory will result in an
2333 error. Arguments are processed in the order specified, halting
2334 at the first error, if any.
2336 +*file mtime* 'name ?time?'+::
2337 Return a decimal string giving the time at which file +'name'+
2338 was last modified. The time is measured in the standard UNIX
2339 fashion as seconds from a fixed starting time (often January 1, 1970).
2340 If the file doesn't exist or its modified time cannot be queried then an
2341 error is generated. If +'time'+ is given, sets the modification time
2342 of the file to the given value.
2344 +*file normalize* 'name'+::
2345 Return the normalized path of +'name'+. See 'realpath(3)'.
2347 +*file owned* 'name'+::
2348 Return '1' if file +'name'+ is owned by the current user,
2351 +*file readable* 'name'+::
2352 Return '1' if file +'name'+ is readable by
2353 the current user, '0' otherwise.
2355 +*file readlink* 'name'+::
2356 Returns the value of the symbolic link given by +'name'+ (i.e. the
2357 name of the file it points to). If
2358 +'name'+ isn't a symbolic link or its value cannot be read, then
2359 an error is returned. On systems that don't support symbolic links
2360 this option is undefined.
2362 +*file rename* ?*-force*? 'oldname' 'newname'+::
2363 Renames the file from the old name to the new name.
2364 If +'newname'+ already exists, an error is returned unless +'-force'+ is
2367 +*file rootname* 'name'+::
2368 Return all of the characters in +'name'+ up to but not including
2369 the last '.' character in the name. If +'name'+ doesn't contain
2370 a dot, then return +'name'+.
2372 +*file size* 'name'+::
2373 Return a decimal string giving the size of file +'name'+ in bytes.
2374 If the file doesn't exist or its size cannot be queried then an
2377 +*file stat* 'name ?varName?'+::
2378 Invoke the 'stat' kernel call on +'name'+, and return the result
2379 as a dictionary with the following keys: 'atime',
2380 'ctime', 'dev', 'gid', 'ino', 'mode', 'mtime',
2381 'nlink', 'size', 'type', 'uid'.
2382 Each element except 'type' is a decimal string with the value of
2383 the corresponding field from the 'stat' return structure; see the
2384 manual entry for 'stat' for details on the meanings of the values.
2385 The 'type' element gives the type of the file in the same form
2386 returned by the command `file type`.
2387 If +'varName'+ is specified, it is taken to be the name of an array
2388 variable and the values are also stored into the array.
2390 +*file tail* 'name'+::
2391 Return all of the characters in +'name'+ after the last slash.
2392 If +'name'+ contains no slashes then return +'name'+.
2394 +*file tempfile* '?template?'+::
2395 Creates and returns the name of a unique temporary file. If +'template'+ is omitted, a
2396 default template will be used to place the file in /tmp. See 'mkstemp(3)' for
2397 the format of the template and security concerns.
2399 +*file type* 'name'+::
2400 Returns a string giving the type of file +'name'+, which will be
2401 one of +file+, +directory+, +characterSpecial+,
2402 +blockSpecial+, +fifo+, +link+, or +socket+.
2404 +*file writable* 'name'+::
2405 Return '1' if file +'name'+ is writable by
2406 the current user, '0' otherwise.
2408 The `file` commands that return 0/1 results are often used in
2409 conditional or looping commands, for example:
2411 if {![file exists foo]} {
2412 error {bad file name}
2419 +*finalize* 'reference ?command?'+
2421 If +'command'+ is omitted, returns the finalizer command for the given reference.
2423 Otherwise, sets a new finalizer command for the given reference. +'command'+ may be
2424 the empty string to remove the current finalizer.
2426 The reference must be a valid reference create with the `ref`
2429 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2437 Flushes any output that has been buffered for +'fileId'+. +'fileId'+ must
2438 have been the return value from a previous call to `open`, or it may be
2439 +stdout+ or +stderr+ to access one of the standard I/O streams; it must
2440 refer to a file that was opened for writing. This command returns an
2445 +*for* 'start test next body'+
2447 `for` is a looping command, similar in structure to the C `for` statement.
2448 The +'start'+, +'next'+, and +'body'+ arguments must be Tcl command strings,
2449 and +'test'+ is an expression string.
2451 The `for` command first invokes the Tcl interpreter to execute +'start'+.
2452 Then it repeatedly evaluates +'test'+ as an expression; if the result is
2453 non-zero it invokes the Tcl interpreter on +'body'+, then invokes the Tcl
2454 interpreter on +'next'+, then repeats the loop. The command terminates
2455 when +'test'+ evaluates to 0.
2457 If a `continue` command is invoked within +'body'+ then any remaining
2458 commands in the current execution of +'body'+ are skipped; processing
2459 continues by invoking the Tcl interpreter on +'next'+, then evaluating
2460 +'test'+, and so on.
2462 If a `break` command is invoked within +'body'+ or +'next'+, then the `for`
2463 command will return immediately.
2465 The operation of `break` and `continue` are similar to the corresponding
2468 `for` returns an empty string.
2472 +*foreach* 'varName list body'+
2474 +*foreach* 'varList list ?varList2 list2 \...? body'+
2476 In this command, +'varName'+ is the name of a variable, +'list'+
2477 is a list of values to assign to +'varName'+, and +'body'+ is a
2478 collection of Tcl commands.
2480 For each field in +'list'+ (in order from left to right), `foreach` assigns
2481 the contents of the field to +'varName'+ (as if the `lindex` command
2482 had been used to extract the field), then calls the Tcl interpreter to
2485 If instead of being a simple name, +'varList'+ is used, multiple assignments
2486 are made each time through the loop, one for each element of +'varList'+.
2488 For example, if there are two elements in +'varList'+ and six elements in
2489 the list, the loop will be executed three times.
2491 If the length of the list doesn't evenly divide by the number of elements
2492 in +'varList'+, the value of the remaining variables in the last iteration
2493 of the loop are undefined.
2495 The `break` and `continue` statements may be invoked inside +'body'+,
2496 with the same effect as in the `for` command.
2498 `foreach` returns an empty string.
2502 +*format* 'formatString ?arg \...?'+
2504 This command generates a formatted string in the same way as the
2505 C 'sprintf' procedure (it uses 'sprintf' in its
2506 implementation). +'formatString'+ indicates how to format
2507 the result, using +%+ fields as in 'sprintf', and the additional
2508 arguments, if any, provide values to be substituted into the result.
2510 All of the 'sprintf' options are valid; see the 'sprintf'
2511 man page for details. Each +'arg'+ must match the expected type
2512 from the +%+ field in +'formatString'+; the `format` command
2513 converts each argument to the correct type (floating, integer, etc.)
2514 before passing it to 'sprintf' for formatting.
2516 The only unusual conversion is for +%c+; in this case the argument
2517 must be a decimal string, which will then be converted to the corresponding
2518 ASCII (or UTF-8) character value.
2520 In addition, Jim Tcl provides basic support for conversion to binary with +%b+.
2522 `format` does backslash substitution on its +'formatString'+
2523 argument, so backslash sequences in +'formatString'+ will be handled
2524 correctly even if the argument is in braces.
2526 The return value from `format` is the formatted string.
2530 +*getref* 'reference'+
2532 Returns the string associated with +'reference'+. The reference must
2533 be a valid reference create with the `ref` command.
2535 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2539 +*gets* 'fileId ?varName?'+
2541 +'fileId' *gets* '?varName?'+
2543 Reads the next line from the file given by +'fileId'+ and discards
2544 the terminating newline character.
2546 If +'varName'+ is specified, then the line is placed in the variable
2547 by that name and the return value is a count of the number of characters
2548 read (not including the newline).
2550 If the end of the file is reached before reading
2551 any characters then -1 is returned and +'varName'+ is set to an
2554 If +'varName'+ is not specified then the return value will be
2555 the line (minus the newline character) or an empty string if
2556 the end of the file is reached before reading any characters.
2558 An empty string will also be returned if a line contains no characters
2559 except the newline, so `eof` may have to be used to determine
2560 what really happened.
2562 If the last character in the file is not a newline character, then
2563 `gets` behaves as if there were an additional newline character
2564 at the end of the file.
2566 +'fileId'+ must be +stdin+ or the return value from a previous
2567 call to `open`; it must refer to a file that was opened
2572 +*glob* ?*-nocomplain*? ?*-directory* 'dir'? ?*-tails*? ?*--*? 'pattern ?pattern \...?'+
2574 This command performs filename globbing, using csh rules. The returned
2575 value from `glob` is the list of expanded filenames.
2577 If +-nocomplain+ is specified as the first argument then an empty
2578 list may be returned; otherwise an error is returned if the expanded
2579 list is empty. The +-nocomplain+ argument must be provided
2580 exactly: an abbreviation will not be accepted.
2582 If +-directory+ is given, the +'dir'+ is understood to contain a
2583 directory name to search in. This allows globbing inside directories
2584 whose names may contain glob-sensitive characters. The returned names
2585 include the directory name unless +'-tails'+ is specified.
2587 If +'-tails'+ is specified, along with +-directory+, the returned names
2588 are relative to the given directory.
2593 +*global* 'varName ?varName \...?'+
2595 This command is ignored unless a Tcl procedure is being interpreted.
2596 If so, then it declares each given +'varName'+ to be a global variable
2597 rather than a local one. For the duration of the current procedure
2598 (and only while executing in the current procedure), any reference to
2599 +'varName'+ will be bound to a global variable instead
2602 An alternative to using `global` is to use the +::+ prefix
2603 to explicitly name a variable in the global scope.
2607 +*if* 'expr1' ?*then*? 'body1' *elseif* 'expr2' ?*then*? 'body2' *elseif* \... ?*else*? ?'bodyN'?+
2609 The `if` command evaluates +'expr1'+ as an expression (in the same way
2610 that `expr` evaluates its argument). The value of the expression must
2611 be numeric; if it is non-zero then +'body1'+ is executed by passing it to
2612 the Tcl interpreter.
2614 Otherwise +'expr2'+ is evaluated as an expression and if it is non-zero
2615 then +'body2'+ is executed, and so on.
2617 If none of the expressions evaluates to non-zero then +'bodyN'+ is executed.
2619 The +then+ and +else+ arguments are optional "noise words" to make the
2620 command easier to read.
2622 There may be any number of +elseif+ clauses, including zero. +'bodyN'+
2623 may also be omitted as long as +else+ is omitted too.
2625 The return value from the command is the result of the body script that
2626 was executed, or an empty string if none of the expressions was non-zero
2627 and there was no +'bodyN'+.
2631 +*incr* 'varName ?increment?'+
2633 Increment the value stored in the variable whose name is +'varName'+.
2634 The value of the variable must be integral.
2636 If +'increment'+ is supplied then its value (which must be an
2637 integer) is added to the value of variable +'varName'+; otherwise
2638 1 is added to +'varName'+.
2640 The new value is stored as a decimal string in variable +'varName'+
2641 and also returned as result.
2643 If the variable does not exist, the variable is implicitly created
2644 and set to +0+ first.
2649 +*info* 'option ?arg\...?'+::
2651 Provide information about various internals to the Tcl interpreter.
2652 The legal +'option'+'s (which may be abbreviated) are:
2654 +*info args* 'procname'+::
2655 Returns a list containing the names of the arguments to procedure
2656 +'procname'+, in order. +'procname'+ must be the name of a
2657 Tcl command procedure.
2659 +*info alias* 'command'+::
2660 +'command'+ must be an alias created with `alias`. In which case the target
2661 command and arguments, as passed to `alias` are returned. See `exists -alias`
2663 +*info body* 'procname'+::
2664 Returns the body of procedure +'procname'+. +'procname'+ must be
2665 the name of a Tcl command procedure.
2668 Returns a list of all open file handles from `open` or `socket`
2670 +*info commands* ?'pattern'?+::
2671 If +'pattern'+ isn't specified, returns a list of names of all the
2672 Tcl commands, including both the built-in commands written in C and
2673 the command procedures defined using the `proc` command.
2674 If +'pattern'+ is specified, only those names matching +'pattern'+
2675 are returned. Matching is determined using the same rules as for
2678 +*info complete* 'command' ?'missing'?+::
2679 Returns 1 if +'command'+ is a complete Tcl command in the sense of
2680 having no unclosed quotes, braces, brackets or array element names,
2681 If the command doesn't appear to be complete then 0 is returned.
2682 This command is typically used in line-oriented input environments
2683 to allow users to type in commands that span multiple lines; if the
2684 command isn't complete, the script can delay evaluating it until additional
2685 lines have been typed to complete the command. If +'varName'+ is specified, the
2686 missing character is stored in the variable with that name.
2688 +*info exists* 'varName'+::
2689 Returns '1' if the variable named +'varName'+ exists in the
2690 current context (either as a global or local variable), returns '0'
2693 +*info frame* ?'number'?+::
2694 If +'number'+ is not specified, this command returns a number
2695 which is the same result as `info level` - the current stack frame level.
2696 If +'number'+ is specified, then the result is a list consisting of the procedure,
2697 filename and line number for the procedure call at level +'number'+ on the stack.
2698 If +'number'+ is positive then it selects a particular stack level (1 refers
2699 to the top-most active procedure, 2 to the procedure it called, and
2700 so on); otherwise it gives a level relative to the current level
2701 (0 refers to the current procedure, -1 to its caller, and so on).
2702 The level has an identical meaning to `info level`.
2704 +*info globals* ?'pattern'?+::
2705 If +'pattern'+ isn't specified, returns a list of all the names
2706 of currently-defined global variables.
2707 If +'pattern'+ is specified, only those names matching +'pattern'+
2708 are returned. Matching is determined using the same rules as for
2712 An alias for `os.gethostname` for compatibility with Tcl 6.x
2714 +*info level* ?'number'?+::
2715 If +'number'+ is not specified, this command returns a number
2716 giving the stack level of the invoking procedure, or 0 if the
2717 command is invoked at top-level. If +'number'+ is specified,
2718 then the result is a list consisting of the name and arguments for the
2719 procedure call at level +'number'+ on the stack. If +'number'+
2720 is positive then it selects a particular stack level (1 refers
2721 to the top-most active procedure, 2 to the procedure it called, and
2722 so on); otherwise it gives a level relative to the current level
2723 (0 refers to the current procedure, -1 to its caller, and so on).
2724 See the `uplevel` command for more information on what stack
2727 +*info locals* ?'pattern'?+::
2728 If +'pattern'+ isn't specified, returns a list of all the names
2729 of currently-defined local variables, including arguments to the
2730 current procedure, if any. Variables defined with the `global`
2731 and `upvar` commands will not be returned. If +'pattern'+ is
2732 specified, only those names matching +'pattern'+ are returned.
2733 Matching is determined using the same rules as for `string match`.
2735 +*info nameofexecutable*+::
2736 Returns the name of the binary file from which the application
2737 was invoked. A full path will be returned, unless the path
2738 can't be determined, in which case the empty string will be returned.
2740 +*info procs* ?'pattern'?+::
2741 If +'pattern'+ isn't specified, returns a list of all the
2742 names of Tcl command procedures.
2743 If +'pattern'+ is specified, only those names matching +'pattern'+
2744 are returned. Matching is determined using the same rules as for
2747 +*info references*+::
2748 Returns a list of all references which have not yet been garbage
2751 +*info returncodes* ?'code'?+::
2752 Returns a list representing the mapping of standard return codes
2753 to names. e.g. +{0 ok 1 error 2 return \...}+. If a code is given,
2754 instead returns the name for the given code.
2757 If a Tcl script file is currently being evaluated (i.e. there is a
2758 call to 'Jim_EvalFile' active or there is an active invocation
2759 of the `source` command), then this command returns the name
2760 of the innermost file being processed. Otherwise the command returns an
2763 +*info source* 'script ?filename line?'+::
2764 With a single argument, returns the original source location of the given script as a list of
2765 +{filename linenumber}+. If the source location can't be determined, the
2766 list +{{} 0}+ is returned. If +'filename'+ and +'line'+ are given, returns a copy
2767 of +'script'+ with the associate source information. This can be useful to produce
2768 useful messages from `eval`, etc. if the original source information may be lost.
2770 +*info stacktrace*+::
2771 After an error is caught with `catch`, returns the stack trace as a list
2772 of +{procedure filename line \...}+.
2774 +*info statics* 'procname'+::
2775 Returns a dictionary of the static variables of procedure
2776 +'procname'+. +'procname'+ must be the name of a Tcl command
2777 procedure. An empty dictionary is returned if the procedure has
2778 no static variables.
2781 Returns the version number for this version of Jim in the form +*x.yy*+.
2783 +*info vars* ?'pattern'?+::
2784 If +'pattern'+ isn't specified,
2785 returns a list of all the names of currently-visible variables, including
2786 both locals and currently-visible globals.
2787 If +'pattern'+ is specified, only those names matching +'pattern'+
2788 are returned. Matching is determined using the same rules as for
2793 +*join* 'list ?joinString?'+
2795 The +'list'+ argument must be a valid Tcl list. This command returns the
2796 string formed by joining all of the elements of +'list'+ together with
2797 +'joinString'+ separating each adjacent pair of elements.
2799 The +'joinString'+ argument defaults to a space character.
2803 +*kill* ?'SIG'|*-0*? 'pid'+
2805 Sends the given signal to the process identified by +'pid'+.
2807 The signal may be specified by name or number in one of the following forms:
2815 The signal name may be in either upper or lower case.
2817 The special signal name +-0+ simply checks that a signal +'could'+ be sent.
2819 If no signal is specified, SIGTERM is used.
2821 An error is raised if the signal could not be delivered.
2825 +*lambda* 'args ?statics? body'+
2827 The `lambda` command is identical to `proc`, except rather than
2828 creating a named procedure, it creates an anonymous procedure and returns
2829 the name of the procedure.
2831 See `proc` and GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2835 +*lappend* 'varName value ?value value \...?'+
2837 Treat the variable given by +'varName'+ as a list and append each of
2838 the +'value'+ arguments to that list as a separate element, with spaces
2841 If +'varName'+ doesn't exist, it is created as a list with elements given
2842 by the +'value'+ arguments. `lappend` is similar to `append` except that
2843 each +'value'+ is appended as a list element rather than raw text.
2845 This command provides a relatively efficient way to build up large lists.
2850 is much more efficient than
2852 set a [concat $a [list $b]]
2858 +*lassign* 'list varName ?varName \...?'+
2860 This command treats the value +'list'+ as a list and assigns successive elements from that list to
2861 the variables given by the +'varName'+ arguments in order. If there are more variable names than
2862 list elements, the remaining variables are set to the empty string. If there are more list elements
2863 than variables, a list of unassigned elements is returned.
2865 jim> lassign {1 2 3} a b; puts a=$a,b=$b
2871 +*local* 'cmd ?arg\...?'+
2873 First, `local` evaluates +'cmd'+ with the given arguments. The return value must
2874 be the name of an existing command, which is marked as having local scope.
2875 This means that when the current procedure exits, the specified
2876 command is deleted. This can be useful with `lambda`, local procedures or
2877 to automatically close a filehandle.
2879 In addition, if a command already exists with the same name,
2880 the existing command will be kept rather than deleted, and may be called
2881 via `upcall`. The previous command will be restored when the current
2882 procedure exits. See `upcall` for more details.
2884 In this example, a local procedure is created. Note that the procedure
2885 continues to have global scope while it is active.
2888 # proc ... returns "inner" which is marked local
2889 local proc inner {} {
2890 # will be deleted when 'outer' exits
2897 In this example, the lambda is deleted at the end of the procedure rather
2898 than waiting until garbage collection.
2901 set x [lambda inner {args} {
2902 # will be deleted when 'outer' exits
2904 # Use 'function' here which simply returns $x
2913 +*loop* 'var first limit ?incr? body'+
2915 Similar to `for` except simpler and possibly more efficient.
2916 With a positive increment, equivalent to:
2918 for {set var $first} {$var < $limit} {incr var $incr} $body
2920 If +'incr'+ is not specified, 1 is used.
2921 Note that setting the loop variable inside the loop does not
2922 affect the loop count.
2926 +*lindex* 'list ?index ...?'+
2928 Treats +'list'+ as a Tcl list and returns element +'index'+ from it
2929 (0 refers to the first element of the list).
2930 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2932 In extracting the element, +'lindex'+ observes the same rules concerning
2933 braces and quotes and backslashes as the Tcl command interpreter; however,
2934 variable substitution and command substitution do not occur.
2936 If no index values are given, simply returns +'list'+
2938 If +'index'+ is negative or greater than or equal to the number of elements
2939 in +'list'+, then an empty string is returned.
2941 If additional index arguments are supplied, then each argument is
2942 used in turn to select an element from the previous indexing
2943 operation, allowing the script to select elements from sublists.
2947 +*linsert* 'list index element ?element element \...?'+
2949 This command produces a new list from +'list'+ by inserting all
2950 of the +'element'+ arguments just before the element +'index'+
2951 of +'list'+. Each +'element'+ argument will become
2952 a separate element of the new list. If +'index'+ is less than
2953 or equal to zero, then the new elements are inserted at the
2954 beginning of the list. If +'index'+ is greater than or equal
2955 to the number of elements in the list, then the new elements are
2956 appended to the list.
2958 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2963 +*list* 'arg ?arg \...?'+
2965 This command returns a list comprised of all the arguments, +'arg'+. Braces
2966 and backslashes get added as necessary, so that the `lindex` command
2967 may be used on the result to re-extract the original arguments, and also
2968 so that `eval` may be used to execute the resulting list, with
2969 +'arg1'+ comprising the command's name and the other args comprising
2970 its arguments. `list` produces slightly different results than
2971 `concat`: `concat` removes one level of grouping before forming
2972 the list, while `list` works directly from the original arguments.
2973 For example, the command
2975 list a b {c d e} {f {g h}}
2979 a b {c d e} {f {g h}}
2981 while `concat` with the same arguments will return
2989 Treats +'list'+ as a list and returns a decimal string giving
2990 the number of elements in it.
2994 +*lset* 'varName ?index ..? newValue'+
2996 Sets an element in a list.
2998 The `lset` command accepts a parameter, +'varName'+, which it interprets
2999 as the name of a variable containing a Tcl list. It also accepts
3000 zero or more indices into the list. Finally, it accepts a new value
3001 for an element of varName. If no indices are presented, the command
3004 lset varName newValue
3006 In this case, newValue replaces the old value of the variable
3009 When presented with a single index, the `lset` command
3010 treats the content of the varName variable as a Tcl list. It addresses
3011 the index'th element in it (0 refers to the first element of the
3012 list). When interpreting the list, `lset` observes the same rules
3013 concerning braces and quotes and backslashes as the Tcl command
3014 interpreter; however, variable substitution and command substitution
3015 do not occur. The command constructs a new list in which the
3016 designated element is replaced with newValue. This new list is
3017 stored in the variable varName, and is also the return value from
3020 If index is negative or greater than or equal to the number of
3021 elements in $varName, then an error occurs.
3023 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
3025 If additional index arguments are supplied, then each argument is
3026 used in turn to address an element within a sublist designated by
3027 the previous indexing operation, allowing the script to alter
3028 elements in sublists. The command,
3032 replaces element 2 of sublist 1 with +'newValue'+.
3034 The integer appearing in each index argument must be greater than
3035 or equal to zero. The integer appearing in each index argument must
3036 be strictly less than the length of the corresponding list. In other
3037 words, the `lset` command cannot change the size of a list. If an
3038 index is outside the permitted range, an error is reported.
3043 +*lmap* 'varName list body'+
3045 +*lmap* 'varList list ?varList2 list2 \...? body'+
3047 `lmap` is a "collecting" `foreach` which returns a list of its results.
3051 jim> lmap i {1 2 3 4 5} {expr $i*$i}
3053 jim> lmap a {1 2 3} b {A B C} {list $a $b}
3056 If the body invokes `continue`, no value is added for this iteration.
3057 If the body invokes `break`, the loop ends and no more values are added.
3063 Loads the dynamic extension, +'filename'+. Generally the filename should have
3064 the extension +.so+. The initialisation function for the module must be based
3065 on the name of the file. For example loading +hwaccess.so+ will invoke
3066 the initialisation function, +Jim_hwaccessInit+. Normally the `load` command
3067 should not be used directly. Instead it is invoked automatically by `package require`.
3071 +*lrange* 'list first last'+
3073 +'list'+ must be a valid Tcl list. This command will return a new
3074 list consisting of elements +'first'+ through +'last'+, inclusive.
3076 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3078 If +'last'+ is greater than or equal to the number of elements
3079 in the list, then it is treated as if it were +end+.
3081 If +'first'+ is greater than +'last'+ then an empty string
3084 Note: +"`lrange` 'list first first'"+ does not always produce the
3085 same result as +"`lindex` 'list first'"+ (although it often does
3086 for simple fields that aren't enclosed in braces); it does, however,
3087 produce exactly the same results as +"`list` [`lindex` 'list first']"+
3092 +*lreplace* 'list first last ?element element \...?'+
3094 Returns a new list formed by replacing one or more elements of
3095 +'list'+ with the +'element'+ arguments.
3097 +'first'+ gives the index in +'list'+ of the first element
3100 If +'first'+ is less than zero then it refers to the first
3101 element of +'list'+; the element indicated by +'first'+
3102 must exist in the list.
3104 +'last'+ gives the index in +'list'+ of the last element
3105 to be replaced; it must be greater than or equal to +'first'+.
3107 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3109 The +'element'+ arguments specify zero or more new arguments to
3110 be added to the list in place of those that were deleted.
3112 Each +'element'+ argument will become a separate element of
3115 If no +'element'+ arguments are specified, then the elements
3116 between +'first'+ and +'last'+ are simply deleted.
3120 +*lrepeat* 'number element1 ?element2 \...?'+
3122 Build a list by repeating elements +'number'+ times (which must be
3123 a positive integer).
3132 Returns the list in reverse order.
3134 jim> lreverse {1 2 3}
3139 +*lsearch* '?options? list pattern'+
3141 This command searches the elements +'list'+ to see if one of them matches +'pattern'+. If so, the
3142 command returns the index of the first matching element (unless the options +-all+, +-inline+ or +-bool+ are
3143 specified.) If not, the command returns -1. The option arguments indicates how the elements of
3144 the list are to be matched against pattern and must have one of the values below:
3146 *Note* that this command is different from Tcl in that default match type is +-exact+ rather than +-glob+.
3149 +'pattern'+ is a literal string that is compared for exact equality against each list element.
3150 This is the default.
3153 +'pattern'+ is a glob-style pattern which is matched against each list element using the same
3154 rules as the string match command.
3157 +'pattern'+ is treated as a regular expression and matched against each list element using
3158 the rules described by `regexp`.
3160 +*-command* 'cmdname'+::
3161 +'cmdname'+ is a command which is used to match the pattern against each element of the
3162 list. It is invoked as +'cmdname' ?*-nocase*? 'pattern listvalue'+ and should return 1
3163 for a match, or 0 for no match.
3166 Changes the result to be the list of all matching indices (or all matching values if
3167 +-inline+ is specified as well). If indices are returned, the indices will be in numeric
3168 order. If values are returned, the order of the values will be the order of those values
3169 within the input list.
3172 The matching value is returned instead of its index (or an empty string if no value
3173 matches). If +-all+ is also specified, then the result of the command is the list of all
3174 values that matched. The +-inline+ and +-bool+ options are mutually exclusive.
3177 Changes the result to '1' if a match was found, or '0' otherwise. If +-all+ is also specified,
3178 the result will be a list of '0' and '1' for each element of the list depending upon whether
3179 the corresponding element matches. The +-inline+ and +-bool+ options are mutually exclusive.
3182 This negates the sense of the match, returning the index (or value
3183 if +-inline+ is specified) of the first non-matching value in the
3184 list. If +-bool+ is also specified, the '0' will be returned if a
3185 match is found, or '1' otherwise. If +-all+ is also specified,
3186 non-matches will be returned rather than matches.
3189 Causes comparisons to be handled in a case-insensitive manner.
3193 +*lsort* ?*-index* 'listindex'? ?*-nocase|-integer|-real|-command* 'cmdname'? ?*-unique*? ?*-decreasing*|*-increasing*? 'list'+
3195 Sort the elements of +'list'+, returning a new list in sorted order.
3196 By default, ASCII (or UTF-8) sorting is used, with the result in increasing order.
3198 If +-nocase+ is specified, comparisons are case-insensitive.
3200 If +-integer+ is specified, numeric sorting is used.
3202 If +-real+ is specified, floating point number sorting is used.
3204 If +-command 'cmdname'+ is specified, +'cmdname'+ is treated as a command
3205 name. For each comparison, +'cmdname $value1 $value2+' is called which
3206 should compare the values and return an integer less than, equal
3207 to, or greater than zero if the +'$value1'+ is to be considered less
3208 than, equal to, or greater than +'$value2'+, respectively.
3210 If +-decreasing+ is specified, the resulting list is in the opposite
3211 order to what it would be otherwise. +-increasing+ is the default.
3213 If +-unique+ is specified, then only the last set of duplicate elements found in the list will be retained.
3214 Note that duplicates are determined relative to the comparison used in the sort. Thus if +-index 0+ is used,
3215 +{1 a}+ and +{1 b}+ would be considered duplicates and only the second element, +{1 b}+, would be retained.
3217 If +-index 'listindex'+ is specified, each element of the list is treated as a list and
3218 the given index is extracted from the list for comparison. The list index may
3219 be any valid list index, such as +1+, +end+ or +end-2+.
3223 +*open* 'fileName ?access?'+
3225 +*open* '|command-pipeline ?access?'+
3227 Opens a file and returns an identifier
3228 that may be used in future invocations
3229 of commands like `read`, `puts`, and `close`.
3230 +'fileName'+ gives the name of the file to open.
3232 The +'access'+ argument indicates the way in which the file is to be accessed.
3233 It may have any of the following values:
3236 Open the file for reading only; the file must already exist.
3239 Open the file for both reading and writing; the file must
3243 Open the file for writing only. Truncate it if it exists. If it doesn't
3244 exist, create a new file.
3247 Open the file for reading and writing. Truncate it if it exists.
3248 If it doesn't exist, create a new file.
3251 Open the file for writing only. The file must already exist, and the file
3252 is positioned so that new data is appended to the file.
3255 Open the file for reading and writing. If the file doesn't
3256 exist, create a new empty file. Set the initial access position
3257 to the end of the file.
3259 +'access'+ defaults to 'r'.
3261 If a file is opened for both reading and writing, then `seek`
3262 must be invoked between a read and a write, or vice versa.
3264 If the first character of +'fileName'+ is "|" then the remaining
3265 characters of +'fileName'+ are treated as a list of arguments that
3266 describe a command pipeline to invoke, in the same style as the
3267 arguments for exec. In this case, the channel identifier returned
3268 by open may be used to write to the command's input pipe or read
3269 from its output pipe, depending on the value of +'access'+. If write-only
3270 access is used (e.g. +'access'+ is 'w'), then standard output for the
3271 pipeline is directed to the current standard output unless overridden
3272 by the command. If read-only access is used (e.g. +'access'+ is r),
3273 standard input for the pipeline is taken from the current standard
3274 input unless overridden by the command.
3276 The `pid` command may be used to return the process ids of the commands
3277 forming the command pipeline.
3279 See also `socket`, `pid`, `exec`
3283 +*package provide* 'name ?version?'+
3285 Indicates that the current script provides the package named +'name'+.
3286 If no version is specified, '1.0' is used.
3288 Any script which provides a package may include this statement
3289 as the first statement, although it is not required.
3291 +*package require* 'name ?version?'*+
3293 Searches for the package with the given +'name'+ by examining each path
3294 in '$::auto_path' and trying to load '$path/$name.so' as a dynamic extension,
3295 or '$path/$name.tcl' as a script package.
3297 The first such file which is found is considered to provide the package.
3298 (The version number is ignored).
3300 If '$name.so' exists, it is loaded with the `load` command,
3301 otherwise if '$name.tcl' exists it is loaded with the `source` command.
3303 If `load` or `source` fails, `package require` will fail immediately.
3304 No further attempt will be made to locate the file.
3312 The first form returns the process identifier of the current process.
3314 The second form accepts a handle returned by `open` and returns a list
3315 of the process ids forming the pipeline in the same form as `exec ... &`.
3316 If 'fileId' represents a regular file handle rather than a command pipeline,
3317 the empty string is returned instead.
3319 See also `open`, `exec`
3323 +*proc* 'name args ?statics? body'+
3325 The `proc` command creates a new Tcl command procedure, +'name'+.
3326 When the new command is invoked, the contents of +'body'+ will be executed.
3327 Tcl interpreter. +'args'+ specifies the formal arguments to the procedure.
3328 If specified, +'static'+, declares static variables which are bound to the
3331 See PROCEDURES for detailed information about Tcl procedures.
3333 The `proc` command returns +'name'+ (which is useful with `local`).
3335 When a procedure is invoked, the procedure's return value is the
3336 value specified in a `return` command. If the procedure doesn't
3337 execute an explicit `return`, then its return value is the value
3338 of the last command executed in the procedure's body.
3340 If an error occurs while executing the procedure body, then the
3341 procedure-as-a-whole will return that same error.
3345 +*puts* ?*-nonewline*? '?fileId? string'+
3347 +'fileId' *puts* ?*-nonewline*? 'string'+
3349 Writes the characters given by +'string'+ to the file given
3350 by +'fileId'+. +'fileId'+ must have been the return
3351 value from a previous call to `open`, or it may be
3352 +stdout+ or +stderr+ to refer to one of the standard I/O
3353 channels; it must refer to a file that was opened for
3356 In the first form, if no +'fileId'+ is specified then it defaults to +stdout+.
3357 `puts` normally outputs a newline character after +'string'+,
3358 but this feature may be suppressed by specifying the +-nonewline+
3361 Output to files is buffered internally by Tcl; the `flush`
3362 command may be used to force buffered characters to be output.
3368 Returns the path name of the current working directory.
3372 +*rand* '?min? ?max?'+
3374 Returns a random integer between +'min'+ (defaults to 0) and +'max'+
3375 (defaults to the maximum integer).
3377 If only one argument is given, it is interpreted as +'max'+.
3381 +*range* '?start? end ?step?'+
3383 Returns a list of integers starting at +'start'+ (defaults to 0)
3384 and ranging up to but not including +'end'+ in steps of +'step'+ defaults to 1).
3397 +*read* ?*-nonewline*? 'fileId'+
3399 +'fileId' *read* ?*-nonewline*?+
3401 +*read* 'fileId numBytes'+
3403 +'fileId' *read* 'numBytes'+
3406 In the first form, all of the remaining bytes are read from the file
3407 given by +'fileId'+; they are returned as the result of the command.
3408 If the +-nonewline+ switch is specified then the last
3409 character of the file is discarded if it is a newline.
3411 In the second form, the extra argument specifies how many bytes to read;
3412 exactly this many bytes will be read and returned, unless there are fewer than
3413 +'numBytes'+ bytes left in the file; in this case, all the remaining
3416 +'fileId'+ must be +stdin+ or the return value from a previous call
3417 to `open`; it must refer to a file that was opened for reading.
3421 +*regexp ?-nocase? ?-line? ?-indices? ?-start* 'offset'? *?-all? ?-inline? ?--?* 'exp string ?matchVar? ?subMatchVar subMatchVar \...?'+
3423 Determines whether the regular expression +'exp'+ matches part or
3424 all of +'string'+ and returns 1 if it does, 0 if it doesn't.
3426 See REGULAR EXPRESSIONS above for complete information on the
3427 syntax of +'exp'+ and how it is matched against +'string'+.
3429 If additional arguments are specified after +'string'+ then they
3430 are treated as the names of variables to use to return
3431 information about which part(s) of +'string'+ matched +'exp'+.
3432 +'matchVar'+ will be set to the range of +'string'+ that
3433 matched all of +'exp'+. The first +'subMatchVar'+ will contain
3434 the characters in +'string'+ that matched the leftmost parenthesized
3435 subexpression within +'exp'+, the next +'subMatchVar'+ will
3436 contain the characters that matched the next parenthesized
3437 subexpression to the right in +'exp'+, and so on.
3439 Normally, +'matchVar'+ and the each +'subMatchVar'+ are set to hold the
3440 matching characters from `string`, however see +-indices+ and
3443 If there are more values for +'subMatchVar'+ than parenthesized subexpressions
3444 within +'exp'+, or if a particular subexpression in +'exp'+ doesn't
3445 match the string (e.g. because it was in a portion of the expression
3446 that wasn't matched), then the corresponding +'subMatchVar'+ will be
3447 set to +"-1 -1"+ if +-indices+ has been specified or to an empty
3450 The following switches modify the behaviour of +'regexp'+
3453 Causes upper-case and lower-case characters to be treated as
3454 identical during the matching process.
3457 Use newline-sensitive matching. By default, newline
3458 is a completely ordinary character with no special meaning in
3459 either REs or strings. With this flag, +[^+ bracket expressions
3460 and +.+ never match newline, an +^+ anchor matches the null
3461 string after any newline in the string in addition to its normal
3462 function, and the +$+ anchor matches the null string before any
3463 newline in the string in addition to its normal function.
3466 Changes what is stored in the subMatchVars. Instead of
3467 storing the matching characters from string, each variable
3468 will contain a list of two decimal strings giving the indices
3469 in string of the first and last characters in the matching
3470 range of characters.
3472 +*-start* 'offset'+::
3473 Specifies a character index offset into the string at which to start
3474 matching the regular expression. If +-indices+ is
3475 specified, the indices will be indexed starting from the
3476 absolute beginning of the input string. +'offset'+ will be
3477 constrained to the bounds of the input string.
3480 Causes the regular expression to be matched as many times as possible
3481 in the string, returning the total number of matches found. If this
3482 is specified with match variables, they will contain information
3483 for the last match only.
3486 Causes the command to return, as a list, the data that would otherwise
3487 be placed in match variables. When using +-inline+, match variables
3488 may not be specified. If used with +-all+, the list will be concatenated
3489 at each iteration, such that a flat list is always returned. For
3490 each match iteration, the command will append the overall match
3491 data, plus one element for each subexpression in the regular
3495 Marks the end of switches. The argument following this one will be
3496 treated as +'exp'+ even if it starts with a +-+.
3500 +*regsub ?-nocase? ?-all? ?-line? ?-start* 'offset'? ?*--*? 'exp string subSpec ?varName?'+
3502 This command matches the regular expression +'exp'+ against
3503 +'string'+ using the rules described in REGULAR EXPRESSIONS
3506 If +'varName'+ is specified, the commands stores +'string'+ to +'varName'+
3507 with the substitutions detailed below, and returns the number of
3508 substitutions made (normally 1 unless +-all+ is specified).
3509 This is 0 if there were no matches.
3511 If +'varName'+ is not specified, the substituted string will be returned
3514 When copying +'string'+, the portion of +'string'+ that
3515 matched +'exp'+ is replaced with +'subSpec'+.
3516 If +'subSpec'+ contains a +&+ or +{backslash}0+, then it is replaced
3517 in the substitution with the portion of +'string'+ that
3520 If +'subSpec'+ contains a +{backslash}n+, where +'n'+ is a digit
3521 between 1 and 9, then it is replaced in the substitution with
3522 the portion of +'string'+ that matched the +'n'+\'-th
3523 parenthesized subexpression of +'exp'+.
3524 Additional backslashes may be used in +'subSpec'+ to prevent special
3525 interpretation of +&+ or +{backslash}0+ or +{backslash}n+ or
3528 The use of backslashes in +'subSpec'+ tends to interact badly
3529 with the Tcl parser's use of backslashes, so it's generally
3530 safest to enclose +'subSpec'+ in braces if it includes
3533 The following switches modify the behaviour of +'regsub'+
3536 Upper-case characters in +'string'+ are converted to lower-case
3537 before matching against +'exp'+; however, substitutions
3538 specified by +'subSpec'+ use the original unconverted form
3542 All ranges in +'string'+ that match +'exp'+ are found and substitution
3543 is performed for each of these ranges, rather than only the
3544 first. The +&+ and +{backslash}n+ sequences are handled for
3545 each substitution using the information from the corresponding
3549 Use newline-sensitive matching. By default, newline
3550 is a completely ordinary character with no special meaning in
3551 either REs or strings. With this flag, +[^+ bracket expressions
3552 and +.+ never match newline, an +^+ anchor matches the null
3553 string after any newline in the string in addition to its normal
3554 function, and the +$+ anchor matches the null string before any
3555 newline in the string in addition to its normal function.
3557 +*-start* 'offset'+::
3558 Specifies a character index offset into the string at which to
3559 start matching the regular expression. +'offset'+ will be
3560 constrained to the bounds of the input string.
3563 Marks the end of switches. The argument following this one will be
3564 treated as +'exp'+ even if it starts with a +-+.
3568 +*ref* 'string tag ?finalizer?'+
3570 Create a new reference containing +'string'+ of type +'tag'+.
3571 If +'finalizer'+ is specified, it is a command which will be invoked
3572 when the a garbage collection cycle runs and this reference is
3573 no longer accessible.
3575 The finalizer is invoked as:
3577 finalizer reference string
3579 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
3583 +*rename* 'oldName newName'+
3585 Rename the command that used to be called +'oldName'+ so that it
3586 is now called +'newName'+. If +'newName'+ is an empty string
3587 (e.g. {}) then +'oldName'+ is deleted. The `rename` command
3588 returns an empty string as result.
3592 +*return* ?*-code* 'code'? ?*-errorinfo* 'stacktrace'? ?*-errorcode* 'errorcode'? ?*-level* 'n'? ?'value'?+
3594 Return immediately from the current procedure (or top-level command
3595 or `source` command), with +'value'+ as the return value. If +'value'+
3596 is not specified, an empty string will be returned as result.
3598 If +-code+ is specified (as either a number or ok, error, break,
3599 continue, signal, return or exit), this code will be used instead
3600 of +JIM_OK+. This is generally useful when implementing flow of control
3603 If +-level+ is specified and greater than 1, it has the effect of delaying
3604 the new return code from +-code+. This is useful when rethrowing an error
3605 from `catch`. See the implementation of try/catch in tclcompat.tcl for
3606 an example of how this is done.
3608 Note: The following options are only used when +-code+ is JIM_ERR.
3610 If +-errorinfo+ is specified (as returned from `info stacktrace`)
3611 it is used to initialize the stacktrace.
3613 If +-errorcode+ is specified, it is used to set the global variable $::errorCode.
3617 +*scan* 'string format varName1 ?varName2 \...?'+
3619 This command parses fields from an input string in the same fashion
3620 as the C 'sscanf' procedure. +'string'+ gives the input to be parsed
3621 and +'format'+ indicates how to parse it, using '%' fields as in
3622 'sscanf'. All of the 'sscanf' options are valid; see the 'sscanf'
3623 man page for details. Each +'varName'+ gives the name of a variable;
3624 when a field is scanned from +'string'+, the result is converted back
3625 into a string and assigned to the corresponding +'varName'+. The
3626 only unusual conversion is for '%c'. For '%c' conversions a single
3627 character value is converted to a decimal string, which is then
3628 assigned to the corresponding +'varName'+; no field width may be
3629 specified for this conversion.
3633 +*seek* 'fileId offset ?origin?'+
3635 +'fileId' *seek* 'offset ?origin?'+
3637 Change the current access position for +'fileId'+.
3638 The +'offset'+ and +'origin'+ arguments specify the position at
3639 which the next read or write will occur for +'fileId'+.
3640 +'offset'+ must be a number (which may be negative) and +'origin'+
3641 must be one of the following:
3644 The new access position will be +'offset'+ bytes from the start
3648 The new access position will be +'offset'+ bytes from the current
3649 access position; a negative +'offset'+ moves the access position
3650 backwards in the file.
3653 The new access position will be +'offset'+ bytes from the end of
3654 the file. A negative +'offset'+ places the access position before
3655 the end-of-file, and a positive +'offset'+ places the access position
3656 after the end-of-file.
3658 The +'origin'+ argument defaults to +start+.
3660 +'fileId'+ must have been the return value from a previous call to
3661 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
3662 of the standard I/O channels.
3664 This command returns an empty string.
3668 +*set* 'varName ?value?'+
3670 Returns the value of variable +'varName'+.
3672 If +'value'+ is specified, then set the value of +'varName'+ to +'value'+,
3673 creating a new variable if one doesn't already exist, and return
3676 If +'varName'+ contains an open parenthesis and ends with a
3677 close parenthesis, then it refers to an array element: the characters
3678 before the open parenthesis are the name of the array, and the characters
3679 between the parentheses are the index within the array.
3680 Otherwise +'varName'+ refers to a scalar variable.
3682 If no procedure is active, then +'varName'+ refers to a global
3685 If a procedure is active, then +'varName'+ refers to a parameter
3686 or local variable of the procedure, unless the +'global'+ command
3687 has been invoked to declare +'varName'+ to be global.
3689 The +::+ prefix may also be used to explicitly reference a variable
3690 in the global scope.
3694 +*setref* 'reference string'+
3696 Store a new string in +'reference'+, replacing the existing string.
3697 The reference must be a valid reference create with the `ref`
3700 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
3704 Command for signal handling.
3706 See `kill` for the different forms which may be used to specify signals.
3708 Commands which return a list of signal names do so using the canonical form:
3711 +*signal handle* ?'signals \...'?+::
3712 If no signals are given, returns a list of all signals which are currently
3714 If signals are specified, these are added to the list of signals currently
3717 +*signal ignore* ?'signals \...'?+::
3718 If no signals are given, returns a lists all signals which are currently
3720 If signals are specified, these are added to the list of signals
3721 currently being ignored. These signals are still delivered, but
3722 are not considered by `catch -signal` or `try -signal`. Use
3723 `signal check` to determine which signals have occurred but
3726 +*signal default* ?'signals \...'?+::
3727 If no signals are given, returns a lists all signals which are currently have
3728 the default behaviour.
3729 If signals are specified, these are added to the list of signals which have
3730 the default behaviour.
3732 +*signal check ?-clear?* ?'signals \...'?+::
3733 Returns a list of signals which have been delivered to the process
3734 but are 'ignored'. If signals are specified, only that set of signals will
3735 be checked, otherwise all signals will be checked.
3736 If +-clear+ is specified, any signals returned are removed and will not be
3737 returned by subsequent calls to `signal check` unless delivered again.
3739 +*signal throw* ?'signal'?+::
3740 Raises the given signal, which defaults to +SIGINT+ if not specified.
3741 The behaviour is identical to:
3745 Note that `signal handle` and `signal ignore` represent two forms of signal
3746 handling. `signal handle` is used in conjunction with `catch -signal` or `try -signal`
3747 to immediately abort execution when the signal is delivered. Alternatively, `signal ignore`
3748 is used in conjunction with `signal check` to handle signal synchronously. Consider the
3751 Prevent a processing from taking too long
3753 signal handle SIGALRM
3756 .. possibly long running process ..
3759 puts stderr "Process took too long"
3762 Handle SIGHUP to reconfigure:
3764 signal ignore SIGHUP
3766 ... handle configuration/reconfiguration ...
3767 while {[signal check -clear SIGHUP] eq ""} {
3768 ... do processing ..
3770 # Received SIGHUP, so reconfigure
3777 Pauses for the given number of seconds, which may be a floating
3778 point value less than one to sleep for less than a second, or an
3779 integer to sleep for one or more seconds.
3783 +*source* 'fileName'+
3785 Read file +'fileName'+ and pass the contents to the Tcl interpreter
3786 as a sequence of commands to execute in the normal fashion. The return
3787 value of `source` is the return value of the last command executed
3788 from the file. If an error occurs in executing the contents of the
3789 file, then the `source` command will return that error.
3791 If a `return` command is invoked from within the file, the remainder of
3792 the file will be skipped and the `source` command will return
3793 normally with the result from the `return` command.
3797 +*split* 'string ?splitChars?'+
3799 Returns a list created by splitting +'string'+ at each character
3800 that is in the +'splitChars'+ argument.
3802 Each element of the result list will consist of the
3803 characters from +'string'+ between instances of the
3804 characters in +'splitChars'+.
3806 Empty list elements will be generated if +'string'+ contains
3807 adjacent characters in +'splitChars'+, or if the first or last
3808 character of +'string'+ is in +'splitChars'+.
3810 If +'splitChars'+ is an empty string then each character of
3811 +'string'+ becomes a separate element of the result list.
3813 +'splitChars'+ defaults to the standard white-space characters.
3816 split "comp.unix.misc" .
3818 returns +'"comp unix misc"'+ and
3820 split "Hello world" {}
3822 returns +'"H e l l o { } w o r l d"'+.
3827 +*stackdump* 'stacktrace'+
3829 Creates a human readable representation of a stack trace.
3836 Returns a live stack trace as a list of +proc file line proc file line \...+.
3837 Iteratively uses `info frame` to create the stack trace. This stack trace is in the
3838 same form as produced by `catch` and `info stacktrace`
3840 See also `stackdump`.
3845 +*string* 'option arg ?arg \...?'+
3847 Perform one of several string operations, depending on +'option'+.
3848 The legal options (which may be abbreviated) are:
3850 +*string bytelength* 'string'+::
3851 Returns the length of the string in bytes. This will return
3852 the same value as `string length` if UTF-8 support is not enabled,
3853 or if the string is composed entirely of ASCII characters.
3854 See UTF-8 AND UNICODE.
3856 +*string byterange* 'string first last'+::
3857 Like `string range` except works on bytes rather than characters.
3858 These commands are identical if UTF-8 support is not enabled.
3860 +*string cat* '?string1 string2 \...?'+::
3861 Concatenates the given strings into a single string.
3863 +*string compare ?-nocase?* ?*-length* 'len? string1 string2'+::
3864 Perform a character-by-character comparison of strings +'string1'+ and
3865 +'string2'+ in the same way as the C 'strcmp' procedure. Return
3866 -1, 0, or 1, depending on whether +'string1'+ is lexicographically
3867 less than, equal to, or greater than +'string2'+. If +-length+
3868 is specified, then only the first +'len'+ characters are used
3869 in the comparison. If +'len'+ is negative, it is ignored.
3870 Performs a case-insensitive comparison if +-nocase+ is specified.
3872 +*string equal ?-nocase?* '?*-length* len?' 'string1 string2'+::
3873 Returns 1 if the strings are equal, or 0 otherwise. If +-length+
3874 is specified, then only the first +'len'+ characters are used
3875 in the comparison. If +'len'+ is negative, it is ignored.
3876 Performs a case-insensitive comparison if +-nocase+ is specified.
3878 +*string first* 'string1 string2 ?firstIndex?'+::
3879 Search +'string2'+ for a sequence of characters that exactly match
3880 the characters in +'string1'+. If found, return the index of the
3881 first character in the first such match within +'string2'+. If not
3882 found, return -1. If +'firstIndex'+ is specified, matching will start
3883 from +'firstIndex'+ of +'string1'+.
3885 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'firstIndex'+.
3887 +*string index* 'string charIndex'+::
3888 Returns the +'charIndex'+'th character of the +'string'+
3889 argument. A +'charIndex'+ of 0 corresponds to the first
3890 character of the string.
3891 If +'charIndex'+ is less than 0 or greater than
3892 or equal to the length of the string then an empty string is
3895 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'charIndex'+.
3897 +*string is* 'class' ?*-strict*? 'string'+::
3898 Returns 1 if +'string'+ is a valid member of the specified character
3899 class, otherwise returns 0. If +-strict+ is specified, then an
3900 empty string returns 0, otherwise an empty string will return 1
3901 on any class. The following character classes are recognized
3902 (the class name can be abbreviated):
3904 +alnum+;; Any alphabet or digit character.
3905 +alpha+;; Any alphabet character.
3906 +ascii+;; Any character with a value less than 128 (those that are in the 7-bit ascii range).
3907 +control+;; Any control character.
3908 +digit+;; Any digit character.
3909 +double+;; Any of the valid forms for a double in Tcl, with optional surrounding whitespace.
3910 In case of under/overflow in the value, 0 is returned.
3911 +graph+;; Any printing character, except space.
3912 +integer+;; Any of the valid string formats for an integer value in Tcl, with optional surrounding whitespace.
3913 +lower+;; Any lower case alphabet character.
3914 +print+;; Any printing character, including space.
3915 +punct+;; Any punctuation character.
3916 +space+;; Any space character.
3917 +upper+;; Any upper case alphabet character.
3918 +xdigit+;; Any hexadecimal digit character ([0-9A-Fa-f]).
3920 Note that string classification does +'not'+ respect UTF-8. See UTF-8 AND UNICODE
3922 +*string last* 'string1 string2 ?lastIndex?'+::
3923 Search +'string2'+ for a sequence of characters that exactly match
3924 the characters in +'string1'+. If found, return the index of the
3925 first character in the last such match within +'string2'+. If there
3926 is no match, then return -1. If +'lastIndex'+ is specified, only characters
3927 up to +'lastIndex'+ of +'string2'+ will be considered in the match.
3929 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'lastIndex'+.
3931 +*string length* 'string'+::
3932 Returns a decimal string giving the number of characters in +'string'+.
3933 If UTF-8 support is enabled, this may be different than the number of bytes.
3934 See UTF-8 AND UNICODE
3936 +*string map ?-nocase?* 'mapping string'+::
3937 Replaces substrings in +'string'+ based on the key-value pairs in
3938 +'mapping'+, which is a list of +key value key value \...+ as in the form
3939 returned by `array get`. Each instance of a key in the string will be
3940 replaced with its corresponding value. If +-nocase+ is specified, then
3941 matching is done without regard to case differences. Both key and value may
3942 be multiple characters. Replacement is done in an ordered manner, so the
3943 key appearing first in the list will be checked first, and so on. +'string'+ is
3944 only iterated over once, so earlier key replacements will have no affect for
3945 later key matches. For example,
3947 string map {abc 1 ab 2 a 3 1 0} 1abcaababcabababc
3950 will return the string +01321221+.
3952 Note that if an earlier key is a prefix of a later one, it will completely mask the later
3953 one. So if the previous example is reordered like this,
3955 string map {1 0 ab 2 a 3 abc 1} 1abcaababcabababc
3958 it will return the string +02c322c222c+.
3960 +*string match ?-nocase?* 'pattern string'+::
3961 See if +'pattern'+ matches +'string'+; return 1 if it does, 0
3962 if it doesn't. Matching is done in a fashion similar to that
3963 used by the C-shell. For the two strings to match, their contents
3964 must be identical except that the following special sequences
3965 may appear in +'pattern'+:
3968 Matches any sequence of characters in +'string'+,
3969 including a null string.
3972 Matches any single character in +'string'+.
3975 Matches any character in the set given by +'chars'+.
3976 If a sequence of the form +'x-y'+ appears in +'chars'+,
3977 then any character between +'x'+ and +'y'+, inclusive,
3981 Matches the single character +'x'+. This provides a way of
3982 avoiding the special interpretation of the characters +{backslash}*?[]+
3985 Performs a case-insensitive comparison if +-nocase+ is specified.
3987 +*string range* 'string first last'+::
3988 Returns a range of consecutive characters from +'string'+, starting
3989 with the character whose index is +'first'+ and ending with the
3990 character whose index is +'last'+. An index of 0 refers to the
3991 first character of the string.
3993 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3995 If +'first'+ is less than zero then it is treated as if it were zero, and
3996 if +'last'+ is greater than or equal to the length of the string then
3997 it is treated as if it were +end+. If +'first'+ is greater than
3998 +'last'+ then an empty string is returned.
4000 +*string repeat* 'string count'+::
4001 Returns a new string consisting of +'string'+ repeated +'count'+ times.
4003 +*string replace* 'string first last ?newstring?'+::
4004 Removes a range of consecutive characters from +'string'+, starting
4005 with the character whose index is +'first'+ and ending with the
4006 character whose index is +'last'+. If +'newstring'+ is specified,
4007 then it is placed in the removed character range. If +'first'+ is
4008 less than zero then it is treated as if it were zero, and if +'last'+
4009 is greater than or equal to the length of the string then it is
4010 treated as if it were +end+. If +'first'+ is greater than +'last'+
4011 or the length of the initial string, or +'last'+ is less than 0,
4012 then the initial string is returned untouched.
4014 +*string reverse* 'string'+::
4015 Returns a string that is the same length as +'string'+ but
4016 with its characters in the reverse order.
4018 +*string tolower* 'string'+::
4019 Returns a value equal to +'string'+ except that all upper case
4020 letters have been converted to lower case.
4022 +*string totitle* 'string'+::
4023 Returns a value equal to +'string'+ except that the first character
4024 is converted to title case (or upper case if there is no UTF-8 titlecase variant)
4025 and all remaining characters have been converted to lower case.
4027 +*string toupper* 'string'+::
4028 Returns a value equal to +'string'+ except that all lower case
4029 letters have been converted to upper case.
4031 +*string trim* 'string ?chars?'+::
4032 Returns a value equal to +'string'+ except that any leading
4033 or trailing characters from the set given by +'chars'+ are
4035 If +'chars'+ is not specified then white space is removed
4036 (spaces, tabs, newlines, and carriage returns).
4038 +*string trimleft* 'string ?chars?'+::
4039 Returns a value equal to +'string'+ except that any
4040 leading characters from the set given by +'chars'+ are
4042 If +'chars'+ is not specified then white space is removed
4043 (spaces, tabs, newlines, and carriage returns).
4045 +*string trimright* 'string ?chars?'+::
4046 Returns a value equal to +'string'+ except that any
4047 trailing characters from the set given by +'chars'+ are
4049 If +'chars'+ is not specified then white space is removed
4050 (spaces, tabs, newlines, and carriage returns).
4051 Null characters are always removed.
4055 +*subst ?-nobackslashes? ?-nocommands? ?-novariables?* 'string'+
4057 This command performs variable substitutions, command substitutions,
4058 and backslash substitutions on its string argument and returns the
4059 fully-substituted result. The substitutions are performed in exactly
4060 the same way as for Tcl commands. As a result, the string argument
4061 is actually substituted twice, once by the Tcl parser in the usual
4062 fashion for Tcl commands, and again by the subst command.
4064 If any of the +-nobackslashes+, +-nocommands+, or +-novariables+ are
4065 specified, then the corresponding substitutions are not performed.
4066 For example, if +-nocommands+ is specified, no command substitution
4067 is performed: open and close brackets are treated as ordinary
4068 characters with no special interpretation.
4070 *Note*: when it performs its substitutions, subst does not give any
4071 special treatment to double quotes or curly braces. For example,
4072 the following script returns +xyz \{44\}+, not +xyz \{$a\}+.
4080 +*switch* '?options? string pattern body ?pattern body \...?'+
4082 +*switch* '?options? string {pattern body ?pattern body \...?}'+
4084 The `switch` command matches its string argument against each of
4085 the pattern arguments in order. As soon as it finds a pattern that
4086 matches string it evaluates the following body and returns the
4087 result of that evaluation. If the last pattern argument is default
4088 then it matches anything. If no pattern argument matches string and
4089 no default is given, then the `switch` command returns an empty string.
4090 If the initial arguments to switch start with - then they are treated
4091 as options. The following options are currently supported:
4094 Use exact matching when comparing string to a
4095 pattern. This is the default.
4098 When matching string to the patterns, use glob-style
4099 matching (i.e. the same as implemented by the string
4103 When matching string to the patterns, use regular
4104 expression matching (i.e. the same as implemented
4105 by the regexp command).
4107 +-command 'commandname'+::
4108 When matching string to the patterns, use the given command, which
4109 must be a single word. The command is invoked as
4110 'commandname pattern string', or 'commandname -nocase pattern string'
4111 and must return 1 if matched, or 0 if not.
4114 Marks the end of options. The argument following
4115 this one will be treated as string even if it starts
4118 Two syntaxes are provided for the pattern and body arguments. The
4119 first uses a separate argument for each of the patterns and commands;
4120 this form is convenient if substitutions are desired on some of the
4121 patterns or commands. The second form places all of the patterns
4122 and commands together into a single argument; the argument must
4123 have proper list structure, with the elements of the list being the
4124 patterns and commands. The second form makes it easy to construct
4125 multi-line `switch` commands, since the braces around the whole list
4126 make it unnecessary to include a backslash at the end of each line.
4127 Since the pattern arguments are in braces in the second form, no
4128 command or variable substitutions are performed on them; this makes
4129 the behaviour of the second form different than the first form in
4132 If a body is specified as +-+ it means that the body for the next
4133 pattern should also be used as the body for this pattern (if the
4134 next pattern also has a body of +-+ then the body after that is
4135 used, and so on). This feature makes it possible to share a single
4136 body among several patterns.
4138 Below are some examples of `switch` commands:
4140 switch abc a - b {format 1} abc {format 2} default {format 3}
4144 switch -regexp aaab {
4164 +*tailcall* 'cmd ?arg\...?'+
4166 The `tailcall` command provides an optimised way of invoking a command whilst replacing
4167 the current call frame. This is similar to 'exec' in Bourne Shell.
4169 The following are identical except the first immediately replaces the current call frame.
4173 return [uplevel 1 [list a b c]]
4175 `tailcall` is useful as a dispatch mechanism:
4178 tailcall sub_$cmd {*}$args
4189 Returns a decimal string giving the current access position in
4192 +'fileId'+ must have been the return value from a previous call to
4193 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
4194 of the standard I/O channels.
4198 +*throw* 'code ?msg?'+
4200 This command throws an exception (return) code along with an optional message.
4201 This command is mostly for convenient usage with `try`.
4203 The command +throw break+ is equivalent to +break+.
4204 The command +throw 20 message+ can be caught with an +on 20 \...+ clause to `try`.
4208 +*time* 'command ?count?'+
4210 This command will call the Tcl interpreter +'count'+
4211 times to execute +'command'+ (or once if +'count'+ isn't
4212 specified). It will then return a string of the form
4214 503 microseconds per iteration
4216 which indicates the average amount of time required per iteration,
4219 Time is measured in elapsed time, not CPU time.
4223 +*try* '?catchopts? tryscript' ?*on* 'returncodes {?resultvar? ?optsvar?} handlerscript \...'? ?*finally* 'finalscript'?+
4225 The `try` command is provided as a convenience for exception handling.
4227 This interpeter first evaluates +'tryscript'+ under the effect of the catch
4228 options +'catchopts'+ (e.g. +-signal -noexit --+, see `catch`).
4230 It then evaluates the script for the first matching 'on' handler
4231 (there many be zero or more) based on the return code from the `try`
4232 section. For example a normal +JIM_ERR+ error will be matched by
4233 an 'on error' handler.
4235 Finally, any +'finalscript'+ is evaluated.
4237 The result of this command is the result of +'tryscript'+, except in the
4238 case where an exception occurs in a matching 'on' handler script or the 'finally' script,
4239 in which case the result is this new exception.
4241 The specified +'returncodes'+ is a list of return codes either as names ('ok', 'error', 'break', etc.)
4244 If +'resultvar'+ and +'optsvar'+ are specified, they are set as for `catch` before evaluating
4245 the matching handler.
4252 } on {continue break} {} {
4253 error "Unexpected break/continue"
4254 } on error {msg opts} {
4255 puts "Dealing with error"
4256 return {*}$opts $msg
4258 puts "Got signal: $sig"
4263 If break, continue or error are raised, they are dealt with by the matching
4266 In any case, the file will be closed via the 'finally' clause.
4268 See also `throw`, `catch`, `return`, `error`.
4272 +*unknown* 'cmdName ?arg arg ...?'+
4274 This command doesn't actually exist as part of Tcl, but Tcl will
4275 invoke it if it does exist.
4277 If the Tcl interpreter encounters a command name for which there
4278 is not a defined command, then Tcl checks for the existence of
4279 a command named `unknown`.
4281 If there is no such command, then the interpreter returns an
4284 If the `unknown` command exists, then it is invoked with
4285 arguments consisting of the fully-substituted name and arguments
4286 for the original non-existent command.
4288 The `unknown` command typically does things like searching
4289 through library directories for a command procedure with the name
4290 +'cmdName'+, or expanding abbreviated command names to full-length,
4291 or automatically executing unknown commands as UNIX sub-processes.
4293 In some cases (such as expanding abbreviations) `unknown` will
4294 change the original command slightly and then (re-)execute it.
4295 The result of the `unknown` command is used as the result for
4296 the original non-existent command.
4300 +*unset ?-nocomplain? ?--?* '?name name ...?'+
4303 Each +'name'+ is a variable name, specified in any of the
4304 ways acceptable to the `set` command.
4306 If a +'name'+ refers to an element of an array, then that
4307 element is removed without affecting the rest of the array.
4309 If a +'name'+ consists of an array name with no parenthesized
4310 index, then the entire array is deleted.
4312 The `unset` command returns an empty string as result.
4314 An error occurs if any of the variables doesn't exist, unless '-nocomplain'
4315 is specified. The '--' argument may be specified to stop option processing
4316 in case the variable name may be '-nocomplain'.
4320 +*upcall* 'command ?args ...?'+
4322 May be used from within a proc defined as `local` `proc` in order to call
4323 the previous, hidden version of the same command.
4325 If there is no previous definition of the command, an error is returned.
4329 +*uplevel* '?level? command ?command ...?'+
4331 All of the +'command'+ arguments are concatenated as if they had
4332 been passed to `concat`; the result is then evaluated in the
4333 variable context indicated by +'level'+. `uplevel` returns
4334 the result of that evaluation. If +'level'+ is an integer, then
4335 it gives a distance (up the procedure calling stack) to move before
4336 executing the command. If +'level'+ consists of +\#+ followed by
4337 a number then the number gives an absolute level number. If +'level'+
4338 is omitted then it defaults to +1+. +'level'+ cannot be
4339 defaulted if the first +'command'+ argument starts with a digit or +#+.
4341 For example, suppose that procedure 'a' was invoked
4342 from top-level, and that it called 'b', and that 'b' called 'c'.
4343 Suppose that 'c' invokes the `uplevel` command. If +'level'+
4344 is +1+ or +#2+ or omitted, then the command will be executed
4345 in the variable context of 'b'. If +'level'+ is +2+ or +#1+
4346 then the command will be executed in the variable context of 'a'.
4348 If +'level'+ is '3' or +#0+ then the command will be executed
4349 at top-level (only global variables will be visible).
4350 The `uplevel` command causes the invoking procedure to disappear
4351 from the procedure calling stack while the command is being executed.
4352 In the above example, suppose 'c' invokes the command
4354 uplevel 1 {set x 43; d}
4356 where 'd' is another Tcl procedure. The `set` command will
4357 modify the variable 'x' in 'b's context, and 'd' will execute
4358 at level 3, as if called from 'b'. If it in turn executes
4363 then the `set` command will modify the same variable 'x' in 'b's
4364 context: the procedure 'c' does not appear to be on the call stack
4365 when 'd' is executing. The command `info level` may
4366 be used to obtain the level of the current procedure.
4368 `uplevel` makes it possible to implement new control
4369 constructs as Tcl procedures (for example, `uplevel` could
4370 be used to implement the `while` construct as a Tcl procedure).
4374 +*upvar* '?level? otherVar myVar ?otherVar myVar ...?'+
4376 This command arranges for one or more local variables in the current
4377 procedure to refer to variables in an enclosing procedure call or
4378 to global variables.
4380 +'level'+ may have any of the forms permitted for the `uplevel`
4381 command, and may be omitted if the first letter of the first +'otherVar'+
4382 isn't +#+ or a digit (it defaults to '1').
4384 For each +'otherVar'+ argument, `upvar` makes the variable
4385 by that name in the procedure frame given by +'level'+ (or at
4386 global level, if +'level'+ is +#0+) accessible
4387 in the current procedure by the name given in the corresponding
4390 The variable named by +'otherVar'+ need not exist at the time of the
4391 call; it will be created the first time +'myVar'+ is referenced, just like
4392 an ordinary variable.
4394 `upvar` may only be invoked from within procedures.
4396 `upvar` returns an empty string.
4398 The `upvar` command simplifies the implementation of call-by-name
4399 procedure calling and also makes it easier to build new control constructs
4401 For example, consider the following procedure:
4408 'add2' is invoked with an argument giving the name of a variable,
4409 and it adds two to the value of that variable.
4410 Although 'add2' could have been implemented using `uplevel`
4411 instead of `upvar`, `upvar` makes it simpler for 'add2'
4412 to access the variable in the caller's procedure frame.
4416 +*while* 'test body'+
4418 The +'while'+ command evaluates +'test'+ as an expression
4419 (in the same way that `expr` evaluates its argument).
4420 The value of the expression must be numeric; if it is non-zero
4421 then +'body'+ is executed by passing it to the Tcl interpreter.
4423 Once +'body'+ has been executed then +'test'+ is evaluated
4424 again, and the process repeats until eventually +'test'+
4425 evaluates to a zero numeric value. `continue`
4426 commands may be executed inside +'body'+ to terminate the current
4427 iteration of the loop, and `break`
4428 commands may be executed inside +'body'+ to cause immediate
4429 termination of the `while` command.
4431 The `while` command always returns an empty string.
4436 The following extensions may or may not be available depending upon
4437 what options were selected when Jim Tcl was built.
4440 posix: os.fork, os.wait, os.gethostname, os.getids, os.uptime
4441 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4443 Invokes 'fork(2)' and returns the result.
4445 +*os.wait -nohang* 'pid'+::
4446 Invokes waitpid(2), with WNOHANG if +-nohang+ is specified.
4447 Returns a list of 3 elements.
4449 {0 none 0} if -nohang is specified, and the process is still alive.
4451 {-1 error <error-description>} if the process does not exist or has already been waited for.
4453 {<pid> exit <exit-status>} if the process exited normally.
4455 {<pid> signal <signal-number>} if the process terminated on a signal.
4457 {<pid> other 0} otherwise (core dump, stopped, continued, etc.)
4459 +*os.gethostname*+::
4460 Invokes 'gethostname(3)' and returns the result.
4463 Returns the various user/group ids for the current process.
4466 uid 1000 euid 1000 gid 100 egid 100
4469 Returns the number of seconds since system boot. See description of 'uptime' in 'sysinfo(2)'.
4471 ANSI I/O (aio) and EVENTLOOP API
4472 --------------------------------
4473 Jim provides an alternative object-based API for I/O.
4475 See `open` and `socket` for commands which return an I/O handle.
4479 +$handle *accept* ?addrvar?+::
4480 Server socket only: Accept a connection and return stream.
4481 If +'addrvar'+ is specified, the address of the connected client is stored
4482 in the named variable in the form 'addr:port'. See `socket` for details.
4484 +$handle *buffering none|line|full*+::
4485 Sets the buffering mode of the stream.
4487 +$handle *close* ?r(ead)|w(rite)?+::
4489 The two-argument form is a "half-close" on a socket. See the +shutdown(2)+ man page.
4491 +$handle *copyto* 'tofd ?size?'+::
4492 Copy bytes to the file descriptor +'tofd'+. If +'size'+ is specified, at most
4493 that many bytes will be copied. Otherwise copying continues until the end
4494 of the input file. Returns the number of bytes actually copied.
4497 Returns 1 if stream is at eof
4499 +$handle *filename*+::
4500 Returns the original filename associated with the handle.
4501 Handles returned by `socket` give the socket type instead of a filename.
4506 +$handle *gets* '?var?'+::
4507 Read one line and return it or store it in the var
4509 +$handle *isatty*+::
4510 Returns 1 if the stream is a tty device.
4512 +$handle *ndelay ?0|1?*+::
4513 Set O_NDELAY (if arg). Returns current/new setting.
4514 Note that in general ANSI I/O interacts badly with non-blocking I/O.
4517 +$handle *puts ?-nonewline?* 'str'+::
4518 Write the string, with newline unless -nonewline
4520 +$handle *read ?-nonewline?* '?len?'+::
4521 Read and return bytes from the stream. To eof if no len.
4523 +$handle *recvfrom* 'maxlen ?addrvar?'+::
4524 Receives a message from the handle via recvfrom(2) and returns it.
4525 At most +'maxlen'+ bytes are read.
4526 If +'addrvar'+ is specified, the sending address of the message is stored in
4527 the named variable in the form 'addr:port'. See `socket` for details.
4529 +$handle *seek* 'offset' *?start|current|end?*+::
4530 Seeks in the stream (default 'current')
4532 +$handle *sendto* 'str ?addr:?port'+::
4533 Sends the string, +'str'+, to the given address via the socket using sendto(2).
4534 This is intended for udp/dgram sockets and may give an error or behave in unintended
4535 ways for other handle types.
4536 Returns the number of bytes written.
4539 Flush the stream, then fsync(2) to commit any changes to storage.
4540 Only available on platforms that support fsync(2).
4543 Returns the current seek position
4545 +$handle *ssl* *?-server cert priv?*+::
4546 Initiates a SSL/TLS session and returns a new stream
4548 +$handle *verify*+::
4549 Verifies the certificate of a SSL/TLS stream peer
4551 +*load_ssl_certs* 'dir'+::
4552 Loads SSL/TLS CA certificates for use during verification
4556 +*fconfigure* 'handle' *?-blocking 0|1? ?-buffering noneline|full? ?-translation* 'mode'?+::
4557 For compatibility with Tcl, a limited form of the `fconfigure`
4558 command is supported.
4559 * `fconfigure ... -blocking` maps to `aio ndelay`
4560 * `fconfigure ... -buffering` maps to `aio buffering`
4561 * `fconfigure ... -translation` is accepted but ignored
4564 eventloop: after, vwait, update
4565 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4567 The following commands allow a script to be invoked when the given condition occurs.
4568 If no script is given, returns the current script. If the given script is the empty, the
4571 +$handle *readable* '?readable-script?'+::
4572 Sets or returns the script for when the socket is readable.
4574 +$handle *writable* '?writable-script?'+::
4575 Sets or returns the script for when the socket is writable.
4577 +$handle *onexception* '?exception-script?'+::
4578 Sets or returns the script for when oob data received.
4580 For compatibility with 'Tcl', these may be prefixed with `fileevent`. e.g.
4583 +fileevent $handle *readable* '\...'+
4585 Time-based execution is also available via the eventloop API.
4588 Sleeps for the given number of milliseconds. No events are
4589 processed during this time.
4591 +*after* 'ms'|*idle* 'script ?script \...?'+::
4592 The scripts are concatenated and executed after the given
4593 number of milliseconds have elapsed. If 'idle' is specified,
4594 the script will run the next time the event loop is processed
4595 with `vwait` or `update`. The script is only run once and
4596 then removed. Returns an event id.
4598 +*after cancel* 'id|command'+::
4599 Cancels an `after` event with the given event id or matching
4600 command (script). Returns the number of milliseconds
4601 remaining until the event would have fired. Returns the
4602 empty string if no matching event is found.
4604 +*after info* '?id?'+::
4605 If +'id'+ is not given, returns a list of current `after`
4606 events. If +'id'+ is given, returns a list containing the
4607 associated script and either 'timer' or 'idle' to indicated
4608 the type of the event. An error occurs if +'id'+ does not
4611 +*vwait* 'variable'+::
4612 A call to `vwait` is enters the eventloop. `vwait` processes
4613 events until the named (global) variable changes or all
4614 event handlers are removed. The variable need not exist
4615 beforehand. If there are no event handlers defined, `vwait`
4616 returns immediately.
4618 +*update ?idletasks?*+::
4619 A call to `update` enters the eventloop to process expired events, but
4620 no new events. If 'idletasks' is specified, only expired time events are handled,
4622 Returns once handlers have been run for all expired events.
4624 Scripts are executed at the global scope. If an error occurs during a handler script,
4625 an attempt is made to call (the user-defined command) `bgerror` with the details of the error.
4626 If the `bgerror` command does not exist, the error message details are printed to stderr instead.
4628 If a file event handler script generates an error, the handler is automatically removed
4629 to prevent infinite errors. (A time event handler is always removed after execution).
4632 Called when an event handler script generates an error. Note that the normal command resolution
4633 rules are used for bgerror. First the name is resolved in the current namespace, then in the
4638 Various socket types may be created.
4640 +*socket unix* 'path'+::
4641 A unix domain socket client.
4643 +*socket unix.server* 'path'+::
4644 A unix domain socket server.
4646 +*socket ?-ipv6? stream* 'addr:port'+::
4647 A TCP socket client. (See the forms for +'addr'+ below)
4649 +*socket ?-ipv6? stream.server* '?addr:?port'+::
4650 A TCP socket server (+'addr'+ defaults to +0.0.0.0+ for IPv4 or +[::]+ for IPv6).
4652 +*socket ?-ipv6? dgram* ?'addr:port'?+::
4653 A UDP socket client. If the address is not specified,
4654 the client socket will be unbound and 'sendto' must be used
4655 to indicated the destination.
4657 +*socket ?-ipv6? dgram.server* 'addr:port'+::
4658 A UDP socket server.
4661 A pipe. Note that unlike all other socket types, this command returns
4662 a list of two channels: {read write}
4665 A socketpair (see socketpair(2)). Like `socket pipe`, this command returns
4666 a list of two channels: {s1 s2}. These channels are both readable and writable.
4668 This command creates a socket connected (client) or bound (server) to the given
4671 The returned value is channel and may generally be used with the various file I/O
4672 commands (gets, puts, read, etc.), either as object-based syntax or Tcl-compatible syntax.
4674 set f [socket stream www.google.com:80]
4676 $f puts -nonewline "GET / HTTP/1.0\r\n\r\n"
4681 Server sockets, however support only 'accept', which is most useful in conjunction with
4684 set f [socket stream.server 80]
4686 set client [$f accept]
4689 $client puts -nonewline "HTTP/1.1 404 Not found\r\n"
4694 The address, +'addr'+, can be given in one of the following forms:
4696 1. For IPv4 socket types, an IPv4 address such as 192.168.1.1
4697 2. For IPv6 socket types, an IPv6 address such as [fe80::1234] or [::]
4700 Note that on many systems, listening on an IPv6 address such as [::] will
4701 also accept requests via IPv4.
4703 Where a hostname is specified, the +'first'+ returned address is used
4704 which matches the socket type is used.
4706 The special type 'pipe' isn't really a socket.
4708 lassign [socket pipe] r w
4710 # Must close $w after exec
4718 +*syslog* '?options? ?priority? message'+
4720 This command sends message to system syslog facility with given
4721 priority. Valid priorities are:
4723 emerg, alert, crit, err, error, warning, notice, info, debug
4725 If a message is specified, but no priority is specified, then a
4726 priority of info is used.
4728 By default, facility user is used and the value of global tcl variable
4729 argv0 is used as ident string. However, any of the following options
4730 may be specified before priority to control these parameters:
4732 +*-facility* 'value'+::
4733 Use specified facility instead of user. The following
4734 values for facility are recognized:
4736 authpriv, cron, daemon, kernel, lpr, mail, news, syslog, user,
4739 +*-ident* 'string'+::
4740 Use given string instead of argv0 variable for ident string.
4742 +*-options* 'integer'+::
4743 Set syslog options such as +LOG_CONS+, +LOG_NDELAY+. You should
4744 use numeric values of those from your system syslog.h file,
4745 because I haven't got time to implement yet another hash
4750 The optional 'pack' extension provides commands to encode and decode binary strings.
4752 +*pack* 'varName value' *-intle|-intbe|-floatle|-floatbe|-str* 'bitwidth ?bitoffset?'+::
4753 Packs the binary representation of +'value'+ into the variable
4754 +'varName'+. The value is packed according to the given type
4755 (integer/floating point/string, big-endian/little-endian), width and bit offset.
4756 The variable is created if necessary (like `append`).
4757 The variable is expanded if necessary.
4759 +*unpack* 'binvalue' *-intbe|-intle|-uintbe|-uintle|-floatbe|-floatle|-str* 'bitpos bitwidth'+::
4760 Unpacks bits from +'binvalue'+ at bit position +'bitpos'+ and with +'bitwidth'+.
4761 Interprets the value according to the type (integer/floating point/string, big-endian/little-endian
4762 and signed/unsigned) and returns it. For integer types, +'bitwidth'+
4763 may be up to the size of a Jim Tcl integer (typically 64 bits). For floating point types,
4764 +'bitwidth'+ may be 32 bits (for single precision numbers) or 64 bits (for double precision).
4765 For the string type, both the width and the offset must be on a byte boundary (multiple of 8). Attempting to
4766 access outside the length of the value will return 0 for integer types, 0.0 for floating point types
4767 or the empty string for the string type.
4771 The optional, pure-Tcl 'binary' extension provides the Tcl-compatible `binary scan` and `binary format`
4772 commands based on the low-level `pack` and `unpack` commands.
4774 See the Tcl documentation at: http://www.tcl.tk/man/tcl8.5/TclCmd/binary.htm
4776 Note that 'binary format' with f/r/R specifiers (single-precision float) uses the value of Infinity
4777 in case of overflow.
4781 The optional, pure-Tcl 'oo' extension provides object-oriented (OO) support for Jim Tcl.
4783 See the online documentation (http://jim.tcl.tk/index.html/doc/www/www/documentation/oo/) for more details.
4785 +*class* 'classname ?baseclasses? classvars'+::
4786 Create a new class, +'classname'+, with the given dictionary
4787 (+'classvars'+) as class variables. These are the initial variables
4788 which all newly created objects of this class are initialised with.
4789 If a list of baseclasses is given, methods and instance variables
4792 +*super* 'method ?args \...?'+::
4793 From within a method, invokes the given method on the base class.
4794 Note that this will only call the last baseclass given.
4798 The optional, pure-Tcl 'tree' extension implements an OO, general purpose tree structure
4799 similar to that provided by tcllib ::struct::tree (http://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/struct/struct_tree.html)
4801 A tree is a collection of nodes, where each node (except the root node) has a single parent
4802 and zero or more child nodes (ordered), as well as zero or more attribute/value pairs.
4805 Creates and returns a new tree object with a single node named "root".
4806 All operations on the tree are invoked through this object.
4809 Destroy the tree and all it's nodes. (Note that the tree will also
4810 be automatically garbage collected once it goes out of scope).
4812 +$tree *set* 'nodename key value'+::
4813 Set the value for the given attribute key.
4815 +$tree *lappend* 'nodename key value \...'+::
4816 Append to the (list) value(s) for the given attribute key, or set if not yet set.
4818 +$tree *keyexists* 'nodename key'+::
4819 Returns 1 if the given attribute key exists.
4821 +$tree *get* 'nodename key'+::
4822 Returns the value associated with the given attribute key.
4824 +$tree *getall* 'nodename'+::
4825 Returns the entire attribute dictionary associated with the given key.
4827 +$tree *depth* 'nodename'+::
4828 Returns the depth of the given node. The depth of "root" is 0.
4830 +$tree *parent* 'nodename'+::
4831 Returns the node name of the parent node, or "" for the root node.
4833 +$tree *numchildren* 'nodename'+::
4834 Returns the number of child nodes.
4836 +$tree *children* 'nodename'+::
4837 Returns a list of the child nodes.
4839 +$tree *next* 'nodename'+::
4840 Returns the next sibling node, or "" if none.
4842 +$tree *insert* 'nodename ?index?'+::
4843 Add a new child node to the given node. The index is a list index
4844 such as +3+ or +end-2+. The default index is +end+.
4845 Returns the name of the newly added node.
4847 +$tree *walk* 'nodename' *dfs|bfs* {'actionvar nodevar'} 'script'+::
4848 Walks the tree starting from the given node, either breadth first (+bfs+)
4849 depth first (+dfs+).
4850 The value +"enter"+ or +"exit"+ is stored in variable +'actionvar'+.
4851 The name of each node is stored in +'nodevar'+.
4852 The script is evaluated twice for each node, on entry and exit.
4855 Dumps the tree contents to stdout
4859 The optional tclprefix extension provides the Tcl8.6-compatible 'tcl::prefix' command
4860 (http://www.tcl.tk/man/tcl8.6/TclCmd/prefix.htm) for matching strings against a table
4861 of possible values (typically commands or options).
4863 +*tcl::prefix all* 'table string'+::
4864 Returns a list of all elements in +'table'+ that begin with the prefix +'string'+.
4866 +*tcl::prefix longest* 'table string'+::
4867 Returns the longest common prefix of all elements in +'table'+ that begin with the prefix +'string'+.
4869 +*tcl::prefix match* '?options? table string'+::
4870 If +'string'+ equals one element in +'table'+ or is a prefix to
4871 exactly one element, the matched element is returned. If not, the
4872 result depends on the +-error+ option.
4874 * +*-exact*+ Accept only exact matches.
4875 * +*-message* 'string'+ Use +'string'+ in the error message at a mismatch. Default is "option".
4876 * +*-error* 'options'+ The options are used when no match is found. If +'options'+ is
4877 empty, no error is generated and an empty string is returned.
4878 Otherwise the options are used as return options when
4879 generating the error message. The default corresponds to
4884 The optional history extension provides script access to the command line editing
4885 and history support available in 'jimsh'. See 'examples/jtclsh.tcl' for an example.
4886 Note: if line editing support is not available, `history getline` acts like `gets` and
4887 the remaining subcommands do nothing.
4889 +*history load* 'filename'+::
4890 Load history from a (text) file. If the file does not exist or is not readable,
4893 +*history getline* 'prompt ?varname?'+::
4894 Displays the given prompt and allows a line to be entered. Similarly to `gets`,
4895 if +'varname'+ is given, it receives the line and the length of the line is returned,
4896 or -1 on EOF. If +'varname'+ is not given, the line is returned directly.
4898 +*history add* 'line'+::
4899 Adds the given line to the history buffer.
4901 +*history save* 'filename'+::
4902 Saves the current history buffer to the given file.
4905 Displays the current history buffer to standard output.
4909 Provides namespace-related functions. See also: http://www.tcl.tk/man/tcl8.6/TclCmd/namespace.htm
4911 +*namespace code* 'script'+::
4912 Captures the current namespace context for later execution of
4913 the script +'script'+. It returns a new script in which script has
4914 been wrapped in a +*namespace inscope*+ command.
4916 +*namespace current*+::
4917 Returns the fully-qualified name for the current namespace.
4919 +*namespace delete* '?namespace ...?'+::
4920 Deletes all commands and variables with the given namespace prefixes.
4922 +*namespace eval* 'namespace arg ?arg...?'+::
4923 Activates a namespace called +'namespace'+ and evaluates some code in that context.
4925 +*namespace origin* 'command'+::
4926 Returns the fully-qualified name of the original command to which the imported command +'command'+ refers.
4928 +*namespace parent* ?namespace?+::
4929 Returns the fully-qualified name of the parent namespace for namespace +'namespace'+, if given, otherwise
4930 for the current namespace.
4932 +*namespace qualifiers* 'string'+::
4933 Returns any leading namespace qualifiers for +'string'+
4935 +*namespace tail* 'string'+::
4936 Returns the simple name at the end of a qualified string.
4938 +*namespace upvar* 'namespace ?arg...?'+::
4939 This command arranges for zero or more local variables in the current procedure to refer to variables in +'namespace'+
4941 +*namespace which* '?-command|-variable? name'+::
4942 Looks up +'name'+ as either a command (the default) or variable and returns its fully-qualified name.
4944 [[BuiltinVariables]]
4948 The following global variables are created automatically
4952 This variable is set by Jim as an array
4953 whose elements are the environment variables for the process.
4954 Reading an element will return the value of the corresponding
4955 environment variable.
4956 This array is initialised at startup from the `env` command.
4957 It may be modified and will affect the environment passed to
4958 commands invoked with `exec`.
4961 This variable is set by Jim as an array containing information
4962 about the platform on which Jim was built. Currently this includes
4963 'os' and 'platform'.
4966 This variable contains a list of paths to search for packages.
4967 It defaults to a location based on where jim is installed
4968 (e.g. +/usr/local/lib/jim+), but may be changed by +jimsh+
4969 or the embedding application. Note that +jimsh+ will consider
4970 the environment variable +$JIMLIB+ to be a list of colon-separated
4971 list of paths to add to +*auto_path*+.
4974 This variable holds the value of the -errorcode return
4975 option set by the most recent error that occurred in this
4976 interpreter. This list value represents additional information
4977 about the error in a form that is easy to process with
4978 programs. The first element of the list identifies a general
4979 class of errors, and determines the format of the rest of
4980 the list. The following formats for -errorcode return options
4981 are used by the Tcl core; individual applications may define
4982 additional formats. Currently only `exec` sets this variable.
4983 Otherwise it will be +NONE+.
4985 The following global variables are set by jimsh.
4987 +*tcl_interactive*+::
4988 This variable is set to 1 if jimsh is started in interactive mode
4992 This variable is set by Jim as an array containing information
4993 about the platform upon which Jim was built. The following is an
4994 example of the contents of this array.
4996 tcl_platform(byteOrder) = littleEndian
4997 tcl_platform(engine) = Jim
4998 tcl_platform(os) = Darwin
4999 tcl_platform(platform) = unix
5000 tcl_platform(pointerSize) = 8
5001 tcl_platform(threaded) = 0
5002 tcl_platform(wordSize) = 8
5003 tcl_platform(pathSeparator) = :
5006 If jimsh is invoked to run a script, this variable contains the name
5010 If jimsh is invoked to run a script, this variable contains a list
5011 of any arguments supplied to the script.
5014 If jimsh is invoked to run a script, this variable contains the number
5015 of arguments supplied to the script.
5018 The value of argv[0] when jimsh was invoked.
5020 CHANGES IN PREVIOUS RELEASES
5021 ----------------------------
5025 1. +platform_tcl()+ settings are now automatically determined
5026 2. Add aio `$handle filename`
5027 3. Add `info channels`
5028 4. The 'bio' extension is gone. Now `aio` supports 'copyto'.
5029 5. Add `exists` command
5030 6. Add the pure-Tcl 'oo' extension
5031 7. The `exec` command now only uses vfork(), not fork()
5032 8. Unit test framework is less verbose and more Tcl-compatible
5033 9. Optional UTF-8 support
5034 10. Optional built-in regexp engine for better Tcl compatibility and UTF-8 support
5035 11. Command line editing in interactive mode, e.g. 'jimsh'
5039 1. `source` now checks that a script is complete (.i.e. not missing a brace)
5040 2. 'info complete' now uses the real parser and so is 100% accurate
5041 3. Better access to live stack frames with 'info frame', `stacktrace` and `stackdump`
5042 4. `tailcall` no longer loses stack trace information
5043 5. Add `alias` and `curry`
5044 6. `lambda`, `alias` and `curry` are implemented via `tailcall` for efficiency
5045 7. `local` allows procedures to be deleted automatically at the end of the current procedure
5046 8. udp sockets are now supported for both clients and servers.
5047 9. vfork-based exec is now working correctly
5048 10. Add 'file tempfile'
5049 11. Add 'socket pipe'
5050 12. Enhance 'try ... on ... finally' to be more Tcl 8.6 compatible
5051 13. It is now possible to `return` from within `try`
5052 14. IPv6 support is now included
5054 16. Event handlers works better if an error occurs. eof handler has been removed.
5055 17. `exec` now sets $::errorCode, and catch sets opts(-errorcode) for exit status
5056 18. Command pipelines via open "|..." are now supported
5057 19. `pid` can now return pids of a command pipeline
5058 20. Add 'info references'
5059 21. Add support for 'after +'ms'+', 'after idle', 'after info', `update`
5060 22. `exec` now sets environment based on $::env
5062 24. Add support for 'lsort -index'
5066 1. Add support to `exec` for '>&', '>>&', '|&', '2>@1'
5067 2. Fix `exec` error messages when special token (e.g. '>') is the last token
5068 3. Fix `subst` handling of backslash escapes.
5069 4. Allow abbreviated options for `subst`
5070 5. Add support for `return`, `break`, `continue` in subst
5071 6. Many `expr` bug fixes
5072 7. Add support for functions in `expr` (e.g. int(), abs()), and also 'in', 'ni' list operations
5073 8. The variable name argument to `regsub` is now optional
5074 9. Add support for 'unset -nocomplain'
5075 10. Add support for list commands: `lassign`, `lrepeat`
5076 11. Fully-functional `lsearch` is now implemented
5077 12. Add 'info nameofexecutable' and 'info returncodes'
5078 13. Allow `catch` to determine what return codes are caught
5079 14. Allow `incr` to increment an unset variable by first setting to 0
5080 15. Allow 'args' and optional arguments to the left or required arguments in `proc`
5082 17. Add 'try ... finally' command
5088 Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
5089 Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
5090 Copyright 2005 patthoyts - Pat Thoyts <patthoyts@users.sf.net>
5091 Copyright 2008 oharboe - Oyvind Harboe - oyvind.harboe@zylin.com
5092 Copyright 2008 Andrew Lunn <andrew@lunn.ch>
5093 Copyright 2008 Duane Ellis <openocd@duaneellis.com>
5094 Copyright 2008 Uwe Klein <uklein@klein-messgeraete.de>
5095 Copyright 2009 Steve Bennett <steveb@workware.net.au>
5098 Redistribution and use in source and binary forms, with or without
5099 modification, are permitted provided that the following conditions
5101 1. Redistributions of source code must retain the above copyright
5102 notice, this list of conditions and the following disclaimer.
5103 2. Redistributions in binary form must reproduce the above
5104 copyright notice, this list of conditions and the following
5105 disclaimer in the documentation and/or other materials
5106 provided with the distribution.
5108 THIS SOFTWARE IS PROVIDED BY THE JIM TCL PROJECT ``AS IS'' AND ANY
5109 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
5110 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
5111 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
5112 JIM TCL PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
5113 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
5114 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
5115 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
5116 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
5117 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
5118 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
5119 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5121 The views and conclusions contained in the software and documentation
5122 are those of the authors and should not be interpreted as representing
5123 official policies, either expressed or implied, of the Jim Tcl Project.