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. All Tcl character classes are supported (e.g. +[:alnum:]+, +[:digit:]+, +[:space:]+), but...
1029 3. Character classes apply to ASCII characters only
1030 4. Supported shorthand character classes: +{backslash}w+ = +[:alnum:]+, +{backslash}W+ = +^[:alnum:]+, +{backslash}d+ = +[:digit:],+ +{backslash}D+ = +^[:digit:],+ +{backslash}s+ = +[:space:]+, + +{backslash}S+ = +^[:space:]+
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. Partially supported constraint escapes: +{backslash}A+ = start of string, +{backslash}Z+ = end of string
1034 8. Support for the +?+ non-greedy quantifier. e.g. +*?+
1035 9. Support for non-capturing parentheses +(?:...)+
1036 10. Jim Tcl considers that both patterns and strings end at a null character (+\x00+)
1040 Each command produces two results: a code and a string. The
1041 code indicates whether the command completed successfully or not,
1042 and the string gives additional information. The valid codes are
1043 defined in jim.h, and are:
1046 This is the normal return code, and indicates that the command completed
1047 successfully. The string gives the command's return value.
1050 Indicates that an error occurred; the string gives a message describing
1054 Indicates that the `return` command has been invoked, and that the
1055 current procedure (or top-level command or `source` command)
1056 should return immediately. The
1057 string gives the return value for the procedure or command.
1060 Indicates that the `break` command has been invoked, so the
1061 innermost loop should abort immediately. The string should always
1065 Indicates that the `continue` command has been invoked, so the
1066 innermost loop should go on to the next iteration. The string
1067 should always be empty.
1070 Indicates that a signal was caught while executing a commands.
1071 The string contains the name of the signal caught.
1072 See the `signal` and `catch` commands.
1075 Indicates that the command called the `exit` command.
1076 The string contains the exit code.
1078 Tcl programmers do not normally need to think about return codes,
1079 since +JIM_OK+ is almost always returned. If anything else is returned
1080 by a command, then the Tcl interpreter immediately stops processing
1081 commands and returns to its caller. If there are several nested
1082 invocations of the Tcl interpreter in progress, then each nested
1083 command will usually return the error to its caller, until eventually
1084 the error is reported to the top-level application code. The
1085 application will then display the error message for the user.
1087 In a few cases, some commands will handle certain `error` conditions
1088 themselves and not return them upwards. For example, the `for`
1089 command checks for the +JIM_BREAK+ code; if it occurs, then `for`
1090 stops executing the body of the loop and returns +JIM_OK+ to its
1091 caller. The `for` command also handles +JIM_CONTINUE+ codes and the
1092 procedure interpreter handles +JIM_RETURN+ codes. The `catch`
1093 command allows Tcl programs to catch errors and handle them without
1094 aborting command interpretation any further.
1096 The `info returncodes` command may be used to programmatically map between
1097 return codes and names.
1101 Tcl allows you to extend the command interface by defining
1102 procedures. A Tcl procedure can be invoked just like any other Tcl
1103 command (it has a name and it receives one or more arguments).
1104 The only difference is that its body isn't a piece of C code linked
1105 into the program; it is a string containing one or more other
1108 The `proc` command is used to create a new Tcl command procedure:
1110 +*proc* 'name arglist ?statics? body'+
1112 The new command is named +'name'+, and it replaces any existing command
1113 there may have been by that name. Whenever the new command is
1114 invoked, the contents of +'body'+ will be executed by the Tcl
1117 +'arglist'+ specifies the formal arguments to the procedure.
1118 It consists of a list, possibly empty, of the following
1119 argument specifiers:
1122 Required Argument - A simple argument name.
1125 Optional Argument - A two-element list consisting of the
1126 argument name, followed by the default value, which will
1127 be used if the corresponding argument is not supplied.
1130 Reference Argument - The caller is expected to pass the name of
1131 an existing variable. An implicit `upvar 1 'origname' 'name'` is done
1132 to make the variable available in the proc scope.
1135 Variable Argument - The special name +'args'+, which is
1136 assigned all remaining arguments (including none) as a list. The
1137 variable argument may only be specified once. Note that
1138 the syntax +args newname+ may be used to retain the special
1139 behaviour of +'args'+ with a different local name. In this case,
1140 the variable is named +'newname'+ rather than +'args'+.
1142 When the command is invoked, a local variable will be created for each of
1143 the formal arguments to the procedure; its value will be the value
1144 of corresponding argument in the invoking command or the argument's
1147 Arguments with default values need not be specified in a procedure
1148 invocation. However, there must be enough actual arguments for all
1149 required arguments, and there must not be any extra actual arguments
1150 (unless the Variable Argument is specified).
1152 Actual arguments are assigned to formal arguments as in left-to-right
1153 order with the following precedence.
1155 1. Required Arguments (including Reference Arguments)
1156 2. Optional Arguments
1157 3. Variable Argument
1159 The following example illustrates precedence. Assume a procedure declaration:
1161 proc p {{a A} args b {c C} d} {...}
1163 This procedure requires at least two arguments, but can accept an unlimited number.
1164 The following table shows how various numbers of arguments are assigned.
1165 Values marked as +-+ are assigned the default value.
1167 [width="40%",frame="topbot",options="header"]
1169 |Number of arguments|a|args|b|c|d
1177 When +'body'+ is being executed, variable names normally refer to local
1178 variables, which are created automatically when referenced and deleted
1179 when the procedure returns. One local variable is automatically created
1180 for each of the procedure's arguments. Global variables can be
1181 accessed by invoking the `global` command or via the +::+ prefix.
1185 In addition to procedure arguments, Jim procedures may declare static variables.
1186 These variables scoped to the procedure and initialised at procedure definition.
1187 Either from the static variable definition, or from the enclosing scope.
1189 Consider the following example:
1192 jim> proc a {} {a {b 2}} {
1204 The static variable +'a'+ has no initialiser, so it is initialised from
1205 the enclosing scope with the value 1. (Note that it is an error if there
1206 is no variable with the same name in the enclosing scope). However +'b'+
1207 has an initialiser, so it is initialised to 2.
1209 Unlike a local variable, the value of a static variable is retained across
1210 invocations of the procedure.
1212 See the `proc` command for information on how to define procedures
1213 and what happens when they are invoked. See also NAMESPACES.
1215 VARIABLES - SCALARS AND ARRAYS
1216 ------------------------------
1217 Tcl allows the definition of variables and the use of their values
1218 either through '$'-style variable substitution, the `set`
1219 command, or a few other mechanisms.
1221 Variables need not be declared: a new variable will automatically
1222 be created each time a new variable name is used.
1224 Tcl supports two types of variables: scalars and arrays.
1225 A scalar variable has a single value, whereas an array variable
1226 can have any number of elements, each with a name (called
1227 its 'index') and a value.
1229 Array indexes may be arbitrary strings; they need not be numeric.
1230 Parentheses are used refer to array elements in Tcl commands.
1231 For example, the command
1235 will modify the element of 'x' whose index is 'first'
1236 so that its new value is '44'.
1238 Two-dimensional arrays can be simulated in Tcl by using indexes
1239 that contain multiple concatenated values.
1240 For example, the commands
1245 set the elements of 'a' whose indexes are '2,3' and '3,6'.
1247 In general, array elements may be used anywhere in Tcl that scalar
1248 variables may be used.
1250 If an array is defined with a particular name, then there may
1251 not be a scalar variable with the same name.
1253 Similarly, if there is a scalar variable with a particular
1254 name then it is not possible to make array references to the
1257 To convert a scalar variable to an array or vice versa, remove
1258 the existing variable with the `unset` command.
1260 The `array` command provides several features for dealing
1261 with arrays, such as querying the names of all the elements of
1262 the array and converting between an array and a list.
1264 Variables may be either global or local. If a variable
1265 name is used when a procedure isn't being executed, then it
1266 automatically refers to a global variable. Variable names used
1267 within a procedure normally refer to local variables associated with that
1268 invocation of the procedure. Local variables are deleted whenever
1269 a procedure exits. Either `global` command may be used to request
1270 that a name refer to a global variable for the duration of the current
1271 procedure (this is somewhat analogous to 'extern' in C), or the variable
1272 may be explicitly scoped with the +::+ prefix. For example
1288 ARRAYS AS LISTS IN JIM
1289 ----------------------
1290 Unlike Tcl, Jim can automatically convert between a list (with an even
1291 number of elements) and an array value. This is similar to the way Tcl
1292 can convert between a string and a list.
1303 Thus `array set` is equivalent to `set` when the variable does not
1306 The reverse is also true where an array will be converted into
1309 set a(1) one; set a(2) two
1318 Tcl 8.5 introduced the dict command, and Jim Tcl has added a version
1319 of this command. Dictionaries provide efficient access to key-value
1320 pairs, just like arrays, but dictionaries are pure values. This
1321 means that you can pass them to a procedure just as a list or a
1322 string. Tcl dictionaries are therefore much more like Tcl lists,
1323 except that they represent a mapping from keys to values, rather
1324 than an ordered sequence.
1326 You can nest dictionaries, so that the value for a particular key
1327 consists of another dictionary. That way you can elegantly build
1328 complicated data structures, such as hierarchical databases. You
1329 can also combine dictionaries with other Tcl data structures. For
1330 instance, you can build a list of dictionaries that themselves
1333 Dictionaries are values that contain an efficient, order-preserving
1334 mapping from arbitrary keys to arbitrary values. Each key in the
1335 dictionary maps to a single value. They have a textual format that
1336 is exactly that of any list with an even number of elements, with
1337 each mapping in the dictionary being represented as two items in
1338 the list. When a command takes a dictionary and produces a new
1339 dictionary based on it (either returning it or writing it back into
1340 the variable that the starting dictionary was read from) the new
1341 dictionary will have the same order of keys, modulo any deleted
1342 keys and with new keys added on to the end. When a string is
1343 interpreted as a dictionary and it would otherwise have duplicate
1344 keys, only the last value for a particular key is used; the others
1345 are ignored, meaning that, "apple banana" and "apple carrot apple
1346 banana" are equivalent dictionaries (with different string
1349 Note that in Jim, arrays are implemented as dictionaries.
1350 Thus automatic conversion between lists and dictionaries applies
1351 as it does for arrays.
1353 jim> dict set a 1 one
1355 jim> dict set a 2 two
1361 jim> dict set a 3 T three
1362 1 one 2 two 3 {T three}
1364 See the `dict` command for more details.
1368 Tcl added namespaces as a mechanism avoiding name clashes, especially in applications
1369 including a number of 3rd party components. While there is less need for namespaces
1370 in Jim Tcl (which does not strive to support large applications), it is convenient to
1371 provide a subset of the support for namespaces to easy porting code from Tcl.
1373 Jim Tcl currently supports "light-weight" namespaces which should be adequate for most
1374 purposes. This feature is currently experimental. See README.namespaces for more information
1375 and the documentation of the `namespace` command.
1377 GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION
1378 -----------------------------------------------
1379 Unlike Tcl, Jim has some sophisticated support for functional programming.
1380 These are described briefly below.
1382 More information may be found at http://wiki.tcl.tk/13847
1386 A reference can be thought of as holding a value with one level of indirection,
1387 where the value may be garbage collected when unreferenced.
1388 Consider the following example:
1390 jim> set r [ref "One String" test]
1391 <reference.<test___>.00000000000000000000>
1395 The operation `ref` creates a references to the value specified by the
1396 first argument. (The second argument is a "type" used for documentation purposes).
1398 The operation `getref` is the dereferencing operation which retrieves the value
1399 stored in the reference.
1401 jim> setref $r "New String"
1406 The operation `setref` replaces the value stored by the reference. If the old value
1407 is no longer accessible by any reference, it will eventually be automatically be garbage
1412 Normally, all values in Tcl are passed by value. As such values are copied and released
1413 automatically as necessary.
1415 With the introduction of references, it is possible to create values whose lifetime
1416 transcend their scope. To support this, case, the Jim system will periodically identify
1417 and discard objects which are no longer accessible by any reference.
1419 The `collect` command may be used to force garbage collection. Consider a reference created
1422 jim> proc f {ref value} { puts "Finaliser called for $ref,$value" }
1423 jim> set r [ref "One String" test f]
1424 <reference.<test___>.00000000000
1429 Finaliser called for <reference.<test___>.00000000000,One String
1432 Note that once the reference, 'r', was modified so that it no longer
1433 contained a reference to the value, the garbage collector discarded
1434 the value (after calling the finalizer).
1436 The finalizer for a reference may be examined or changed with the `finalize` command
1440 jim> finalize $r newf
1445 Jim provides a garbage collected `lambda` function. This is a procedure
1446 which is able to create an anonymous procedure. Consider:
1448 jim> set f [lambda {a} {{x 0}} { incr x $a }]
1455 This create an anonymous procedure (with the name stored in 'f'), with a static variable
1456 which is incremented by the supplied value and the result returned.
1458 Once the procedure name is no longer accessible, it will automatically be deleted
1459 when the garbage collector runs.
1461 The procedure may also be delete immediately by renaming it "". e.g.
1467 If Jim is built with UTF-8 support enabled (configure --enable-utf),
1468 then most string-related commands become UTF-8 aware. These include,
1469 but are not limited to, `string match`, `split`, `glob`, `scan` and
1472 UTF-8 encoding has many advantages, but one of the complications is that
1473 characters can take a variable number of bytes. Thus the addition of
1474 `string bytelength` which returns the number of bytes in a string,
1475 while `string length` returns the number of characters.
1477 If UTF-8 support is not enabled, all commands treat bytes as characters
1478 and `string bytelength` returns the same value as `string length`.
1480 Note that even if UTF-8 support is not enabled, the +{backslash}uNNNN+ and related syntax
1481 is still available to embed UTF-8 sequences.
1483 Jim Tcl supports all currently defined unicode codepoints. That is 21 bits, up to +'U+1FFFFF'.
1487 Commands such as `string match`, `lsearch -glob`, `array names` and others use string
1488 pattern matching rules. These commands support UTF-8. For example:
1490 string match a\[\ua0-\ubf\]b "a\u00a3b"
1494 +format %c+ allows a unicode codepoint to be be encoded. For example, the following will return
1495 a string with two bytes and one character. The same as +{backslash}ub5+
1499 `format` respects widths as character widths, not byte widths. For example, the following will
1500 return a string with three characters, not three bytes.
1502 format %.3s \ub5\ub6\ub7\ub8
1504 Similarly, +scan ... %c+ allows a UTF-8 to be decoded to a unicode codepoint. The following will set
1505 +'a'+ to 181 (0xb5) and +'b'+ to 65 (0x41).
1507 scan \u00b5A %c%c a b
1509 `scan %s` will also accept a character class, including unicode ranges.
1513 `string is` has *not* been extended to classify UTF-8 characters. Therefore, the following
1514 will return 0, even though the string may be considered to be alphabetic.
1516 string is alpha \ub5Test
1518 This does not affect the string classes 'ascii', 'control', 'digit', 'double', 'integer' or 'xdigit'.
1520 Case Mapping and Conversion
1521 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
1522 Jim provides a simplified unicode case mapping. This means that case conversion
1523 and comparison will not increase or decrease the number of characters in a string.
1524 (Although it may change the number of bytes).
1526 `string toupper` will convert any lowercase letters to their uppercase equivalent.
1527 Any character which is not a letter or has no uppercase equivalent is left unchanged.
1528 Similarly for `string tolower` and `string totitle`.
1530 Commands which perform case insensitive matches, such as `string compare -nocase`
1531 and `lsearch -nocase` fold both strings to uppercase before comparison.
1533 Invalid UTF-8 Sequences
1534 ~~~~~~~~~~~~~~~~~~~~~~~
1535 Some UTF-8 character sequences are invalid, such as those beginning with '0xff',
1536 those which represent character sequences longer than 3 bytes (greater than U+FFFF),
1537 and those which end prematurely, such as a lone '0xc2'.
1539 In these situations, the offending bytes are treated as single characters. For example,
1540 the following returns 2.
1542 string bytelength \xff\xff
1546 If UTF-8 support is enabled, the built-in regular expression engine will be
1547 selected which supports UTF-8 strings and patterns.
1549 See REGULAR EXPRESSIONS
1553 The Tcl library provides the following built-in commands, which will
1554 be available in any application using Tcl. In addition to these
1555 built-in commands, there may be additional commands defined by each
1556 application, plus commands defined as Tcl procedures.
1558 In the command syntax descriptions below, words in +*boldface*+ are
1559 literals that you type verbatim to Tcl.
1561 Words in +'italics'+ are meta-symbols; they serve as names for any of
1562 a range of values that you can type.
1564 Optional arguments or groups of arguments are indicated by enclosing them
1565 in +?question-marks?+.
1567 Ellipses (+\...+) indicate that any number of additional
1568 arguments or groups of arguments may appear, in the same format
1569 as the preceding argument(s).
1580 Delivers the +SIGALRM+ signal to the process after the given
1581 number of seconds. If the platform supports 'ualarm(3)' then
1582 the argument may be a floating point value. Otherwise it must
1585 Note that unless a signal handler for +SIGALRM+ has been installed
1586 (see `signal`), the process will exit on this signal.
1590 +*alias* 'name args\...'+
1592 Creates a single word alias (command) for one or more words. For example,
1593 the following creates an alias for the command `info exists`.
1600 `alias` returns +'name'+, allowing it to be used with `local`.
1602 See also `proc`, `curry`, `lambda`, `local`, `info alias`, `exists -alias`
1606 +*append* 'varName value ?value value ...?'+
1608 Append all of the +'value'+ arguments to the current value
1609 of variable +'varName'+. If +'varName'+ doesn't exist,
1610 it is given a value equal to the concatenation of all the
1611 +'value'+ arguments.
1613 This command provides an efficient way to build up long
1614 variables incrementally.
1615 For example, "`append a $b`" is much more efficient than
1616 "`set a $a$b`" if +$a+ is long.
1620 +*apply* 'lambdaExpr ?arg1 arg2 \...?'+
1622 The command `apply` provides for anonymous procedure calls,
1623 similar to `lambda`, but without command name being created, even temporarily.
1625 The function +'lambdaExpr'+ is a two element list +{args body}+
1626 or a three element list +{args body namespace}+. The first element
1627 args specifies the formal arguments, in the same form as the `proc` and `lambda` commands.
1631 +*array* 'option arrayName ?arg\...?'+
1633 This command performs one of several operations on the
1634 variable given by +'arrayName'+.
1636 Note that in general, if the named array does not exist, the +'array'+ command behaves
1637 as though the array exists but is empty.
1639 The +'option'+ argument determines what action is carried out by the
1640 command. The legal +'options'+ (which may be abbreviated) are:
1642 +*array exists* 'arrayName'+::
1643 Returns 1 if arrayName is an array variable, 0 if there is
1644 no variable by that name. This command is essentially
1645 identical to `info exists`
1647 +*array get* 'arrayName ?pattern?'+::
1648 Returns a list containing pairs of elements. The first
1649 element in each pair is the name of an element in arrayName
1650 and the second element of each pair is the value of the
1651 array element. The order of the pairs is undefined. If
1652 pattern is not specified, then all of the elements of the
1653 array are included in the result. If pattern is specified,
1654 then only those elements whose names match pattern (using
1655 the matching rules of string match) are included. If arrayName
1656 isn't the name of an array variable, or if the array contains
1657 no elements, then an empty list is returned.
1659 +*array names* 'arrayName ?pattern?'+::
1660 Returns a list containing the names of all of the elements
1661 in the array that match pattern. If pattern is omitted then
1662 the command returns all of the element names in the array.
1663 If pattern is specified, then only those elements whose
1664 names match pattern (using the matching rules of string
1665 match) are included. If there are no (matching) elements
1666 in the array, or if arrayName isn't the name of an array
1667 variable, then an empty string is returned.
1669 +*array set* 'arrayName list'+::
1670 Sets the values of one or more elements in arrayName. list
1671 must have a form like that returned by array get, consisting
1672 of an even number of elements. Each odd-numbered element
1673 in list is treated as an element name within arrayName, and
1674 the following element in list is used as a new value for
1675 that array element. If the variable arrayName does not
1676 already exist and list is empty, arrayName is created with
1677 an empty array value.
1679 +*array size* 'arrayName'+::
1680 Returns the number of elements in the array. If arrayName
1681 isn't the name of an array then 0 is returned.
1683 +*array unset* 'arrayName ?pattern?'+::
1684 Unsets all of the elements in the array that match pattern
1685 (using the matching rules of string match). If arrayName
1686 isn't the name of an array variable or there are no matching
1687 elements in the array, no error will be raised. If pattern
1688 is omitted and arrayName is an array variable, then the
1689 command unsets the entire array. The command always returns
1696 This command may be invoked only inside the body of a loop command
1697 such as `for` or `foreach` or `while`. It returns a +JIM_BREAK+ code
1698 to signal the innermost containing loop command to return immediately.
1702 +*case* 'string' ?in? 'patList body ?patList body ...?'+
1704 +*case* 'string' ?in? {'patList body ?patList body ...?'}+
1706 *Note* that the `switch` command should generally be preferred unless compatibility
1707 with Tcl 6.x is desired.
1709 Match +'string'+ against each of the +'patList'+ arguments
1710 in order. If one matches, then evaluate the following +'body'+ argument
1711 by passing it recursively to the Tcl interpreter, and return the result
1712 of that evaluation. Each +'patList'+ argument consists of a single
1713 pattern or list of patterns. Each pattern may contain any of the wild-cards
1714 described under `string match`.
1716 If a +'patList'+ argument is +default+, the corresponding body will be
1717 evaluated if no +'patList'+ matches +'string'+. If no +'patList'+ argument
1718 matches +'string'+ and no default is given, then the `case` command returns
1721 Two syntaxes are provided.
1723 The first uses a separate argument for each of the patterns and commands;
1724 this form is convenient if substitutions are desired on some of the
1725 patterns or commands.
1727 The second form places all of the patterns and commands together into
1728 a single argument; the argument must have proper list structure, with
1729 the elements of the list being the patterns and commands.
1731 The second form makes it easy to construct multi-line case commands,
1732 since the braces around the whole list make it unnecessary to include a
1733 backslash at the end of each line.
1735 Since the +'patList'+ arguments are in braces in the second form,
1736 no command or variable substitutions are performed on them; this makes
1737 the behaviour of the second form different than the first form in some
1740 Below are some examples of `case` commands:
1742 case abc in {a b} {format 1} default {format 2} a* {format 3}
1752 will return '1', and
1767 +*catch* ?-?no?'code \...'? ?--? 'command ?resultVarName? ?optionsVarName?'+
1769 The `catch` command may be used to prevent errors from aborting
1770 command interpretation. `catch` evaluates +'command'+, and returns a
1771 +JIM_OK+ code, regardless of any errors that might occur while
1772 executing +'command'+ (with the possible exception of +JIM_SIGNAL+ -
1775 The return value from `catch` is a decimal string giving the code
1776 returned by the Tcl interpreter after executing +'command'+. This
1777 will be '0' (+JIM_OK+) if there were no errors in +'command'+; otherwise
1778 it will have a non-zero value corresponding to one of the exceptional
1779 return codes (see jim.h for the definitions of code values, or the
1780 `info returncodes` command).
1782 If the +'resultVarName'+ argument is given, then it gives the name
1783 of a variable; `catch` will set the value of the variable to the
1784 string returned from +'command'+ (either a result or an error message).
1786 If the +'optionsVarName'+ argument is given, then it gives the name
1787 of a variable; `catch` will set the value of the variable to a
1788 dictionary. For any return code other than +JIM_RETURN+, the value
1789 for the key +-code+ will be set to the return code. For +JIM_RETURN+
1790 it will be set to the code given in `return -code`. Additionally,
1791 for the return code +JIM_ERR+, the value of the key +-errorinfo+
1792 will contain the current stack trace (the same result as `info stacktrace`),
1793 the value of the key +-errorcode+ will contain the
1794 same value as the global variable $::errorCode, and the value of
1795 the key +-level+ will be the current return level (see `return -level`).
1796 This can be useful to rethrow an error:
1798 if {[catch {...} msg opts]} {
1799 ...maybe do something with the error...
1801 return {*}$opts $msg
1804 Normally `catch` will +'not'+ catch any of the codes +JIM_EXIT+, +JIM_EVAL+ or +JIM_SIGNAL+.
1805 The set of codes which will be caught may be modified by specifying the one more codes before
1808 e.g. To catch +JIM_EXIT+ but not +JIM_BREAK+ or +JIM_CONTINUE+
1810 catch -exit -nobreak -nocontinue -- { ... }
1812 The use of +--+ is optional. It signifies that no more return code options follow.
1814 Note that if a signal marked as `signal handle` is caught with `catch -signal`, the return value
1815 (stored in +'resultVarName'+) is name of the signal caught.
1821 Change the current working directory to +'dirName'+.
1823 Returns an empty string.
1825 This command can potentially be disruptive to an application, so it may
1826 be removed in some applications.
1831 Returns the current time as seconds since the epoch.
1834 Returns the current time in `clicks'.
1836 +*clock microseconds*+::
1837 Returns the current time in microseconds.
1839 +*clock milliseconds*+::
1840 Returns the current time in milliseconds.
1842 +*clock format* 'seconds' ?*-format* 'format?'+::
1843 Format the given time (seconds since the epoch) according to the given
1844 format. See strftime(3) for supported formats.
1845 If no format is supplied, "%c" is used.
1847 +*clock scan* 'str' *-format* 'format'+::
1848 Scan the given time string using the given format string.
1849 See strptime(3) for supported formats.
1857 Closes the file given by +'fileId'+.
1858 +'fileId'+ must be the return value from a previous invocation
1859 of the `open` command; after this command, it should not be
1866 Normally reference garbage collection is automatically performed periodically.
1867 However it may be run immediately with the `collect` command.
1869 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
1873 +*concat* 'arg ?arg \...?'+
1875 This command treats each argument as a list and concatenates them
1876 into a single list. It permits any number of arguments. For example,
1879 concat a b {c d e} {f {g h}}
1891 This command may be invoked only inside the body of a loop command such
1892 as `for` or `foreach` or `while`. It returns a +JIM_CONTINUE+ code to
1893 signal the innermost containing loop command to skip the remainder of
1894 the loop's body but continue with the next iteration of the loop.
1898 +*alias* 'args\...'+
1900 Similar to `alias` except it creates an anonymous procedure (lambda) instead of
1903 the following creates a local, unnamed alias for the command `info exists`.
1905 set e [local curry info exists]
1910 `curry` returns the name of the procedure.
1912 See also `proc`, `alias`, `lambda`, `local`.
1916 +*dict* 'option ?arg\...?'+
1918 Performs one of several operations on dictionary values.
1920 The +'option'+ argument determines what action is carried out by the
1921 command. The legal +'options'+ are:
1923 +*dict create* '?key value \...?'+::
1924 Create and return a new dictionary value that contains each of
1925 the key/value mappings listed as arguments (keys and values
1926 alternating, with each key being followed by its associated
1929 +*dict exists* 'dictionary key ?key \...?'+::
1930 Returns a boolean value indicating whether the given key (or path
1931 of keys through a set of nested dictionaries) exists in the given
1932 dictionary value. This returns a true value exactly when `dict get`
1933 on that path will succeed.
1935 +*dict get* 'dictionary ?key \...?'+::
1936 Given a dictionary value (first argument) and a key (second argument),
1937 this will retrieve the value for that key. Where several keys are
1938 supplied, the behaviour of the command shall be as if the result
1939 of "`dict get $dictVal $key`" was passed as the first argument to
1940 dict get with the remaining arguments as second (and possibly
1941 subsequent) arguments. This facilitates lookups in nested dictionaries.
1942 If no keys are provided, dict would return a list containing pairs
1943 of elements in a manner similar to array get. That is, the first
1944 element of each pair would be the key and the second element would
1945 be the value for that key. It is an error to attempt to retrieve
1946 a value for a key that is not present in the dictionary.
1948 +*dict keys* 'dictionary ?pattern?'+::
1949 Returns a list of the keys in the dictionary.
1950 If pattern is specified, then only those keys whose
1951 names match +'pattern'+ (using the matching rules of string
1952 match) are included.
1954 +*dict merge* ?'dictionary \...'?+::
1955 Return a dictionary that contains the contents of each of the
1956 +'dictionary'+ arguments. Where two (or more) dictionaries
1957 contain a mapping for the same key, the resulting dictionary
1958 maps that key to the value according to the last dictionary on
1959 the command line containing a mapping for that key.
1961 +*dict set* 'dictionaryName key ?key \...? value'+::
1962 This operation takes the +'name'+ of a variable containing a dictionary
1963 value and places an updated dictionary value in that variable
1964 containing a mapping from the given key to the given value. When
1965 multiple keys are present, this operation creates or updates a chain
1966 of nested dictionaries.
1968 +*dict size* 'dictionary'+::
1969 Return the number of key/value mappings in the given dictionary value.
1971 +*dict unset* 'dictionaryName key ?key \...? value'+::
1972 This operation (the companion to `dict set`) takes the name of a
1973 variable containing a dictionary value and places an updated
1974 dictionary value in that variable that does not contain a mapping
1975 for the given key. Where multiple keys are present, this describes
1976 a path through nested dictionaries to the mapping to remove. At
1977 least one key must be specified, but the last key on the key-path
1978 need not exist. All other components on the path must exist.
1980 +*dict with* 'dictionaryName key ?key \...? script'+::
1981 Execute the Tcl script in +'script'+ with the value for each
1982 key in +'dictionaryName'+ mapped to a variable with the same
1983 name. Where one or more keys are given, these indicate a chain
1984 of nested dictionaries, with the innermost dictionary being the
1985 one opened out for the execution of body. Making +'dictionaryName'+
1986 unreadable will make the updates to the dictionary be discarded,
1987 and this also happens if the contents of +'dictionaryName'+ are
1988 adjusted so that the chain of dictionaries no longer exists.
1989 The result of `dict with` is (unless some kind of error occurs)
1990 the result of the evaluation of body.
1992 The variables are mapped in the scope enclosing the `dict with`;
1993 it is recommended that this command only be used in a local
1994 scope (procedure). Because of this, the variables set by
1995 `dict with` will continue to exist after the command finishes (unless
1996 explicitly unset). Note that changes to the contents of +'dictionaryName'+
1997 only happen when +'script'+ terminates.
1999 +*dict for, values, incr, append, lappend, update, info, replace*+ to be documented...
2003 +*env* '?name? ?default?'+
2005 If +'name'+ is supplied, returns the value of +'name'+ from the initial
2006 environment (see getenv(3)). An error is returned if +'name'+ does not
2007 exist in the environment, unless +'default'+ is supplied - in which case
2008 that value is returned instead.
2010 If no arguments are supplied, returns a list of all environment variables
2011 and their values as +{name value \...}+
2013 See also the global variable +::env+
2021 Returns 1 if an end-of-file condition has occurred on +'fileId'+,
2024 +'fileId'+ must have been the return value from a previous call to `open`,
2025 or it may be +stdin+, +stdout+, or +stderr+ to refer to one of the
2026 standard I/O channels.
2030 +*error* 'message ?stacktrace?'+
2032 Returns a +JIM_ERR+ code, which causes command interpretation to be
2033 unwound. +'message'+ is a string that is returned to the application
2034 to indicate what went wrong.
2036 If the +'stacktrace'+ argument is provided and is non-empty,
2037 it is used to initialize the stacktrace.
2039 This feature is most useful in conjunction with the `catch` command:
2040 if a caught error cannot be handled successfully, +'stacktrace'+ can be used
2041 to return a stack trace reflecting the original point of occurrence
2046 error $errMsg [info stacktrace]
2048 See also `errorInfo`, `info stacktrace`, `catch` and `return`
2052 +*errorInfo* 'error ?stacktrace?'+
2054 Returns a human-readable representation of the given error message and stack trace.
2057 if {[catch {...} error]} {
2058 puts stderr [errorInfo $error [info stacktrace]]
2066 +*eval* 'arg ?arg\...?'+
2068 `eval` takes one or more arguments, which together comprise a Tcl
2069 command (or collection of Tcl commands separated by newlines in the
2070 usual way). `eval` concatenates all its arguments in the same
2071 fashion as the `concat` command, passes the concatenated string to the
2072 Tcl interpreter recursively, and returns the result of that
2073 evaluation (or any error generated by it).
2077 +*exec* 'arg ?arg\...?'+
2079 This command treats its arguments as the specification
2080 of one or more UNIX commands to execute as subprocesses.
2081 The commands take the form of a standard shell pipeline;
2082 +|+ arguments separate commands in the
2083 pipeline and cause standard output of the preceding command
2084 to be piped into standard input of the next command (or +|&+ for
2085 both standard output and standard error).
2087 Under normal conditions the result of the `exec` command
2088 consists of the standard output produced by the last command
2089 in the pipeline followed by the standard error output.
2091 If any of the commands writes to its standard error file,
2092 then this will be included in the result after the standard output
2093 of the last command.
2095 Note that unlike Tcl, data written to standard error does not cause
2096 `exec` to return an error.
2098 If any of the commands in the pipeline exit abnormally or
2099 are killed or suspended, then `exec` will return an error.
2100 If no standard error output was produced, or is redirected,
2101 the error message will include the normal result, as above,
2102 followed by error messages describing the abnormal terminations.
2104 If any standard error output was produced, these abnormal termination
2105 messages are suppressed.
2107 If the last character of the result or error message
2108 is a newline then that character is deleted from the result
2109 or error message for consistency with normal
2112 An +'arg'+ may have one of the following special forms:
2115 The standard output of the last command in the pipeline
2116 is redirected to the file. In this situation `exec`
2117 will normally return an empty string.
2120 As above, but append to the file.
2123 The standard output of the last command in the pipeline is
2124 redirected to the given (writable) file descriptor (e.g. stdout,
2125 stderr, or the result of `open`). In this situation `exec`
2126 will normally return an empty string.
2129 The standard error of the last command in the pipeline
2130 is redirected to the file.
2133 As above, but append to the file.
2136 The standard error of the last command in the pipeline is
2137 redirected to the given (writable) file descriptor.
2140 The standard error of the last command in the pipeline is
2141 redirected to the same file descriptor as the standard output.
2144 Both the standard output and standard error of the last command
2145 in the pipeline is redirected to the file.
2148 As above, but append to the file.
2151 The standard input of the first command in the pipeline
2152 is taken from the file.
2155 The standard input of the first command is taken as the
2156 given immediate value.
2159 The standard input of the first command in the pipeline
2160 is taken from the given (readable) file descriptor.
2162 If there is no redirection of standard input, standard error
2163 or standard output, these are connected to the corresponding
2164 input or output of the application.
2166 If the last +'arg'+ is +&+ then the command will be
2167 executed in background.
2168 In this case the standard output from the last command
2169 in the pipeline will
2170 go to the application's standard output unless
2171 redirected in the command, and error output from all
2172 the commands in the pipeline will go to the application's
2173 standard error file. The return value of exec in this case
2174 is a list of process ids (pids) in the pipeline.
2176 Each +'arg'+ becomes one word for a command, except for
2177 +|+, +<+, +<<+, +>+, and +&+ arguments, and the
2178 arguments that follow +<+, +<<+, and +>+.
2180 The first word in each command is taken as the command name;
2181 the directories in the PATH environment variable are searched for
2182 an executable by the given name.
2184 No `glob` expansion or other shell-like substitutions
2185 are performed on the arguments to commands.
2187 If the command fails, the global $::errorCode (and the -errorcode
2188 option in `catch`) will be set to a list, as follows:
2190 +*CHILDKILLED* 'pid sigName msg'+::
2191 This format is used when a child process has been killed
2192 because of a signal. The pid element will be the process's
2193 identifier (in decimal). The sigName element will be the
2194 symbolic name of the signal that caused the process to
2195 terminate; it will be one of the names from the include
2196 file signal.h, such as SIGPIPE. The msg element will be a
2197 short human-readable message describing the signal, such
2198 as "write on pipe with no readers" for SIGPIPE.
2200 +*CHILDSUSP* 'pid sigName msg'+::
2201 This format is used when a child process has been suspended
2202 because of a signal. The pid element will be the process's
2203 identifier, in decimal. The sigName element will be the
2204 symbolic name of the signal that caused the process to
2205 suspend; this will be one of the names from the include
2206 file signal.h, such as SIGTTIN. The msg element will be a
2207 short human-readable message describing the signal, such
2208 as "background tty read" for SIGTTIN.
2210 +*CHILDSTATUS* 'pid code'+::
2211 This format is used when a child process has exited with a
2212 non-zero exit status. The pid element will be the process's
2213 identifier (in decimal) and the code element will be the
2214 exit code returned by the process (also in decimal).
2216 The environment for the executed command is set from $::env (unless
2217 this variable is unset, in which case the original environment is used).
2221 +*exists ?-var|-proc|-command|-alias?* 'name'+
2223 Checks the existence of the given variable, procedure, command
2224 or alias respectively and returns 1 if it exists or 0 if not. This command
2225 provides a more simplified/convenient version of `info exists`,
2226 `info procs` and `info commands`.
2228 If the type is omitted, a type of '-var' is used. The type may be abbreviated.
2232 +*exit* '?returnCode?'+
2234 Terminate the process, returning +'returnCode'+ to the
2235 parent as the exit status.
2237 If +'returnCode'+ isn't specified then it defaults
2240 Note that exit can be caught with `catch`.
2246 Calls the expression processor to evaluate +'arg'+, and returns
2247 the result as a string. See the section EXPRESSIONS above.
2249 Note that Jim supports a shorthand syntax for `expr` as +$(\...)+
2250 The following two are identical.
2252 set x [expr {3 * 2 + 1}]
2257 +*file* 'option name ?arg\...?'+
2259 Operate on a file or a file name. +'name'+ is the name of a file.
2261 +'option'+ indicates what to do with the file name. Any unique
2262 abbreviation for +'option'+ is acceptable. The valid options are:
2264 +*file atime* 'name'+::
2265 Return a decimal string giving the time at which file +'name'+
2266 was last accessed. The time is measured in the standard UNIX
2267 fashion as seconds from a fixed starting time (often January 1, 1970).
2268 If the file doesn't exist or its access time cannot be queried then an
2271 +*file copy ?-force?* 'source target'+::
2272 Copies file +'source'+ to file +'target'+. The source file must exist.
2273 The target file must not exist, unless +-force+ is specified.
2275 +*file delete ?-force? ?--?* 'name\...'+::
2276 Deletes file or directory +'name'+. If the file or directory doesn't exist, nothing happens.
2277 If it can't be deleted, an error is generated. Non-empty directories will not be deleted
2278 unless the +-force+ options is given. In this case no errors will be generated, even
2279 if the file/directory can't be deleted. Use +'--'+ if there is any possibility of
2280 the first name being +'-force'+.
2282 +*file dirname* 'name'+::
2283 Return all of the characters in +'name'+ up to but not including
2284 the last slash character. If there are no slashes in +'name'+
2285 then return +.+ (a single dot). If the last slash in +'name'+ is its first
2286 character, then return +/+.
2288 +*file executable* 'name'+::
2289 Return '1' if file +'name'+ is executable by
2290 the current user, '0' otherwise.
2292 +*file exists* 'name'+::
2293 Return '1' if file +'name'+ exists and the current user has
2294 search privileges for the directories leading to it, '0' otherwise.
2296 +*file extension* 'name'+::
2297 Return all of the characters in +'name'+ after and including the
2298 last dot in +'name'+. If there is no dot in +'name'+ then return
2301 +*file isdirectory* 'name'+::
2302 Return '1' if file +'name'+ is a directory,
2305 +*file isfile* 'name'+::
2306 Return '1' if file +'name'+ is a regular file,
2309 +*file join* 'arg\...'+::
2310 Joins multiple path components. Note that if any components is
2311 an absolute path, the preceding components are ignored.
2312 Thus +"`file` join /tmp /root"+ returns +"/root"+.
2314 +*file link* ?*-hard|-symbolic*? 'newname target'+::
2315 Creates a hard link (default) or symbolic link from +'newname'+ to +'target'+.
2316 Note that the sense of this command is the opposite of `file rename` and `file copy`
2317 and also of `ln`, but this is compatible with Tcl.
2318 An error is returned if +'target'+ doesn't exist or +'newname'+ already exists.
2320 +*file lstat* 'name varName'+::
2321 Same as 'stat' option (see below) except uses the +'lstat'+
2322 kernel call instead of +'stat'+. This means that if +'name'+
2323 refers to a symbolic link the information returned in +'varName'+
2324 is for the link rather than the file it refers to. On systems that
2325 don't support symbolic links this option behaves exactly the same
2326 as the 'stat' option.
2328 +*file mkdir* 'dir1 ?dir2\...?'+::
2329 Creates each directory specified. For each pathname +'dir'+ specified,
2330 this command will create all non-existing parent directories
2331 as well as +'dir'+ itself. If an existing directory is specified,
2332 then no action is taken and no error is returned. Trying to
2333 overwrite an existing file with a directory will result in an
2334 error. Arguments are processed in the order specified, halting
2335 at the first error, if any.
2337 +*file mtime* 'name ?time?'+::
2338 Return a decimal string giving the time at which file +'name'+
2339 was last modified. The time is measured in the standard UNIX
2340 fashion as seconds from a fixed starting time (often January 1, 1970).
2341 If the file doesn't exist or its modified time cannot be queried then an
2342 error is generated. If +'time'+ is given, sets the modification time
2343 of the file to the given value.
2345 +*file normalize* 'name'+::
2346 Return the normalized path of +'name'+. See 'realpath(3)'.
2348 +*file owned* 'name'+::
2349 Return '1' if file +'name'+ is owned by the current user,
2352 +*file readable* 'name'+::
2353 Return '1' if file +'name'+ is readable by
2354 the current user, '0' otherwise.
2356 +*file readlink* 'name'+::
2357 Returns the value of the symbolic link given by +'name'+ (i.e. the
2358 name of the file it points to). If
2359 +'name'+ isn't a symbolic link or its value cannot be read, then
2360 an error is returned. On systems that don't support symbolic links
2361 this option is undefined.
2363 +*file rename* ?*-force*? 'oldname' 'newname'+::
2364 Renames the file from the old name to the new name.
2365 If +'newname'+ already exists, an error is returned unless +'-force'+ is
2368 +*file rootname* 'name'+::
2369 Return all of the characters in +'name'+ up to but not including
2370 the last '.' character in the name. If +'name'+ doesn't contain
2371 a dot, then return +'name'+.
2373 +*file size* 'name'+::
2374 Return a decimal string giving the size of file +'name'+ in bytes.
2375 If the file doesn't exist or its size cannot be queried then an
2378 +*file stat* 'name ?varName?'+::
2379 Invoke the 'stat' kernel call on +'name'+, and return the result
2380 as a dictionary with the following keys: 'atime',
2381 'ctime', 'dev', 'gid', 'ino', 'mode', 'mtime',
2382 'nlink', 'size', 'type', 'uid'.
2383 Each element except 'type' is a decimal string with the value of
2384 the corresponding field from the 'stat' return structure; see the
2385 manual entry for 'stat' for details on the meanings of the values.
2386 The 'type' element gives the type of the file in the same form
2387 returned by the command `file type`.
2388 If +'varName'+ is specified, it is taken to be the name of an array
2389 variable and the values are also stored into the array.
2391 +*file tail* 'name'+::
2392 Return all of the characters in +'name'+ after the last slash.
2393 If +'name'+ contains no slashes then return +'name'+.
2395 +*file tempfile* '?template?'+::
2396 Creates and returns the name of a unique temporary file. If +'template'+ is omitted, a
2397 default template will be used to place the file in /tmp. See 'mkstemp(3)' for
2398 the format of the template and security concerns.
2400 +*file type* 'name'+::
2401 Returns a string giving the type of file +'name'+, which will be
2402 one of +file+, +directory+, +characterSpecial+,
2403 +blockSpecial+, +fifo+, +link+, or +socket+.
2405 +*file writable* 'name'+::
2406 Return '1' if file +'name'+ is writable by
2407 the current user, '0' otherwise.
2409 The `file` commands that return 0/1 results are often used in
2410 conditional or looping commands, for example:
2412 if {![file exists foo]} {
2413 error {bad file name}
2420 +*finalize* 'reference ?command?'+
2422 If +'command'+ is omitted, returns the finalizer command for the given reference.
2424 Otherwise, sets a new finalizer command for the given reference. +'command'+ may be
2425 the empty string to remove the current finalizer.
2427 The reference must be a valid reference create with the `ref`
2430 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2438 Flushes any output that has been buffered for +'fileId'+. +'fileId'+ must
2439 have been the return value from a previous call to `open`, or it may be
2440 +stdout+ or +stderr+ to access one of the standard I/O streams; it must
2441 refer to a file that was opened for writing. This command returns an
2446 +*for* 'start test next body'+
2448 `for` is a looping command, similar in structure to the C `for` statement.
2449 The +'start'+, +'next'+, and +'body'+ arguments must be Tcl command strings,
2450 and +'test'+ is an expression string.
2452 The `for` command first invokes the Tcl interpreter to execute +'start'+.
2453 Then it repeatedly evaluates +'test'+ as an expression; if the result is
2454 non-zero it invokes the Tcl interpreter on +'body'+, then invokes the Tcl
2455 interpreter on +'next'+, then repeats the loop. The command terminates
2456 when +'test'+ evaluates to 0.
2458 If a `continue` command is invoked within +'body'+ then any remaining
2459 commands in the current execution of +'body'+ are skipped; processing
2460 continues by invoking the Tcl interpreter on +'next'+, then evaluating
2461 +'test'+, and so on.
2463 If a `break` command is invoked within +'body'+ or +'next'+, then the `for`
2464 command will return immediately.
2466 The operation of `break` and `continue` are similar to the corresponding
2469 `for` returns an empty string.
2473 +*foreach* 'varName list body'+
2475 +*foreach* 'varList list ?varList2 list2 \...? body'+
2477 In this command, +'varName'+ is the name of a variable, +'list'+
2478 is a list of values to assign to +'varName'+, and +'body'+ is a
2479 collection of Tcl commands.
2481 For each field in +'list'+ (in order from left to right), `foreach` assigns
2482 the contents of the field to +'varName'+ (as if the `lindex` command
2483 had been used to extract the field), then calls the Tcl interpreter to
2486 If instead of being a simple name, +'varList'+ is used, multiple assignments
2487 are made each time through the loop, one for each element of +'varList'+.
2489 For example, if there are two elements in +'varList'+ and six elements in
2490 the list, the loop will be executed three times.
2492 If the length of the list doesn't evenly divide by the number of elements
2493 in +'varList'+, the value of the remaining variables in the last iteration
2494 of the loop are undefined.
2496 The `break` and `continue` statements may be invoked inside +'body'+,
2497 with the same effect as in the `for` command.
2499 `foreach` returns an empty string.
2503 +*format* 'formatString ?arg \...?'+
2505 This command generates a formatted string in the same way as the
2506 C 'sprintf' procedure (it uses 'sprintf' in its
2507 implementation). +'formatString'+ indicates how to format
2508 the result, using +%+ fields as in 'sprintf', and the additional
2509 arguments, if any, provide values to be substituted into the result.
2511 All of the 'sprintf' options are valid; see the 'sprintf'
2512 man page for details. Each +'arg'+ must match the expected type
2513 from the +%+ field in +'formatString'+; the `format` command
2514 converts each argument to the correct type (floating, integer, etc.)
2515 before passing it to 'sprintf' for formatting.
2517 The only unusual conversion is for +%c+; in this case the argument
2518 must be a decimal string, which will then be converted to the corresponding
2519 ASCII (or UTF-8) character value.
2521 In addition, Jim Tcl provides basic support for conversion to binary with +%b+.
2523 `format` does backslash substitution on its +'formatString'+
2524 argument, so backslash sequences in +'formatString'+ will be handled
2525 correctly even if the argument is in braces.
2527 The return value from `format` is the formatted string.
2531 +*getref* 'reference'+
2533 Returns the string associated with +'reference'+. The reference must
2534 be a valid reference create with the `ref` command.
2536 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2540 +*gets* 'fileId ?varName?'+
2542 +'fileId' *gets* '?varName?'+
2544 Reads the next line from the file given by +'fileId'+ and discards
2545 the terminating newline character.
2547 If +'varName'+ is specified, then the line is placed in the variable
2548 by that name and the return value is a count of the number of characters
2549 read (not including the newline).
2551 If the end of the file is reached before reading
2552 any characters then -1 is returned and +'varName'+ is set to an
2555 If +'varName'+ is not specified then the return value will be
2556 the line (minus the newline character) or an empty string if
2557 the end of the file is reached before reading any characters.
2559 An empty string will also be returned if a line contains no characters
2560 except the newline, so `eof` may have to be used to determine
2561 what really happened.
2563 If the last character in the file is not a newline character, then
2564 `gets` behaves as if there were an additional newline character
2565 at the end of the file.
2567 +'fileId'+ must be +stdin+ or the return value from a previous
2568 call to `open`; it must refer to a file that was opened
2573 +*glob* ?*-nocomplain*? ?*-directory* 'dir'? ?*-tails*? ?*--*? 'pattern ?pattern \...?'+
2575 This command performs filename globbing, using csh rules. The returned
2576 value from `glob` is the list of expanded filenames.
2578 If +-nocomplain+ is specified as the first argument then an empty
2579 list may be returned; otherwise an error is returned if the expanded
2580 list is empty. The +-nocomplain+ argument must be provided
2581 exactly: an abbreviation will not be accepted.
2583 If +-directory+ is given, the +'dir'+ is understood to contain a
2584 directory name to search in. This allows globbing inside directories
2585 whose names may contain glob-sensitive characters. The returned names
2586 include the directory name unless +'-tails'+ is specified.
2588 If +'-tails'+ is specified, along with +-directory+, the returned names
2589 are relative to the given directory.
2594 +*global* 'varName ?varName \...?'+
2596 This command is ignored unless a Tcl procedure is being interpreted.
2597 If so, then it declares each given +'varName'+ to be a global variable
2598 rather than a local one. For the duration of the current procedure
2599 (and only while executing in the current procedure), any reference to
2600 +'varName'+ will be bound to a global variable instead
2603 An alternative to using `global` is to use the +::+ prefix
2604 to explicitly name a variable in the global scope.
2608 +*if* 'expr1' ?*then*? 'body1' *elseif* 'expr2' ?*then*? 'body2' *elseif* \... ?*else*? ?'bodyN'?+
2610 The `if` command evaluates +'expr1'+ as an expression (in the same way
2611 that `expr` evaluates its argument). The value of the expression must
2612 be numeric; if it is non-zero then +'body1'+ is executed by passing it to
2613 the Tcl interpreter.
2615 Otherwise +'expr2'+ is evaluated as an expression and if it is non-zero
2616 then +'body2'+ is executed, and so on.
2618 If none of the expressions evaluates to non-zero then +'bodyN'+ is executed.
2620 The +then+ and +else+ arguments are optional "noise words" to make the
2621 command easier to read.
2623 There may be any number of +elseif+ clauses, including zero. +'bodyN'+
2624 may also be omitted as long as +else+ is omitted too.
2626 The return value from the command is the result of the body script that
2627 was executed, or an empty string if none of the expressions was non-zero
2628 and there was no +'bodyN'+.
2632 +*incr* 'varName ?increment?'+
2634 Increment the value stored in the variable whose name is +'varName'+.
2635 The value of the variable must be integral.
2637 If +'increment'+ is supplied then its value (which must be an
2638 integer) is added to the value of variable +'varName'+; otherwise
2639 1 is added to +'varName'+.
2641 The new value is stored as a decimal string in variable +'varName'+
2642 and also returned as result.
2644 If the variable does not exist, the variable is implicitly created
2645 and set to +0+ first.
2650 +*info* 'option ?arg\...?'+::
2652 Provide information about various internals to the Tcl interpreter.
2653 The legal +'option'+'s (which may be abbreviated) are:
2655 +*info args* 'procname'+::
2656 Returns a list containing the names of the arguments to procedure
2657 +'procname'+, in order. +'procname'+ must be the name of a
2658 Tcl command procedure.
2660 +*info alias* 'command'+::
2661 +'command'+ must be an alias created with `alias`. In which case the target
2662 command and arguments, as passed to `alias` are returned. See `exists -alias`
2664 +*info body* 'procname'+::
2665 Returns the body of procedure +'procname'+. +'procname'+ must be
2666 the name of a Tcl command procedure.
2669 Returns a list of all open file handles from `open` or `socket`
2671 +*info commands* ?'pattern'?+::
2672 If +'pattern'+ isn't specified, returns a list of names of all the
2673 Tcl commands, including both the built-in commands written in C and
2674 the command procedures defined using the `proc` command.
2675 If +'pattern'+ is specified, only those names matching +'pattern'+
2676 are returned. Matching is determined using the same rules as for
2679 +*info complete* 'command' ?'missing'?+::
2680 Returns 1 if +'command'+ is a complete Tcl command in the sense of
2681 having no unclosed quotes, braces, brackets or array element names,
2682 If the command doesn't appear to be complete then 0 is returned.
2683 This command is typically used in line-oriented input environments
2684 to allow users to type in commands that span multiple lines; if the
2685 command isn't complete, the script can delay evaluating it until additional
2686 lines have been typed to complete the command. If +'varName'+ is specified, the
2687 missing character is stored in the variable with that name.
2689 +*info exists* 'varName'+::
2690 Returns '1' if the variable named +'varName'+ exists in the
2691 current context (either as a global or local variable), returns '0'
2694 +*info frame* ?'number'?+::
2695 If +'number'+ is not specified, this command returns a number
2696 which is the same result as `info level` - the current stack frame level.
2697 If +'number'+ is specified, then the result is a list consisting of the procedure,
2698 filename and line number for the procedure call at level +'number'+ on the stack.
2699 If +'number'+ is positive then it selects a particular stack level (1 refers
2700 to the top-most active procedure, 2 to the procedure it called, and
2701 so on); otherwise it gives a level relative to the current level
2702 (0 refers to the current procedure, -1 to its caller, and so on).
2703 The level has an identical meaning to `info level`.
2705 +*info globals* ?'pattern'?+::
2706 If +'pattern'+ isn't specified, returns a list of all the names
2707 of currently-defined global variables.
2708 If +'pattern'+ is specified, only those names matching +'pattern'+
2709 are returned. Matching is determined using the same rules as for
2713 An alias for `os.gethostname` for compatibility with Tcl 6.x
2715 +*info level* ?'number'?+::
2716 If +'number'+ is not specified, this command returns a number
2717 giving the stack level of the invoking procedure, or 0 if the
2718 command is invoked at top-level. If +'number'+ is specified,
2719 then the result is a list consisting of the name and arguments for the
2720 procedure call at level +'number'+ on the stack. If +'number'+
2721 is positive then it selects a particular stack level (1 refers
2722 to the top-most active procedure, 2 to the procedure it called, and
2723 so on); otherwise it gives a level relative to the current level
2724 (0 refers to the current procedure, -1 to its caller, and so on).
2725 See the `uplevel` command for more information on what stack
2728 +*info locals* ?'pattern'?+::
2729 If +'pattern'+ isn't specified, returns a list of all the names
2730 of currently-defined local variables, including arguments to the
2731 current procedure, if any. Variables defined with the `global`
2732 and `upvar` commands will not be returned. If +'pattern'+ is
2733 specified, only those names matching +'pattern'+ are returned.
2734 Matching is determined using the same rules as for `string match`.
2736 +*info nameofexecutable*+::
2737 Returns the name of the binary file from which the application
2738 was invoked. A full path will be returned, unless the path
2739 can't be determined, in which case the empty string will be returned.
2741 +*info procs* ?'pattern'?+::
2742 If +'pattern'+ isn't specified, returns a list of all the
2743 names of Tcl command procedures.
2744 If +'pattern'+ is specified, only those names matching +'pattern'+
2745 are returned. Matching is determined using the same rules as for
2748 +*info references*+::
2749 Returns a list of all references which have not yet been garbage
2752 +*info returncodes* ?'code'?+::
2753 Returns a list representing the mapping of standard return codes
2754 to names. e.g. +{0 ok 1 error 2 return \...}+. If a code is given,
2755 instead returns the name for the given code.
2758 If a Tcl script file is currently being evaluated (i.e. there is a
2759 call to 'Jim_EvalFile' active or there is an active invocation
2760 of the `source` command), then this command returns the name
2761 of the innermost file being processed. Otherwise the command returns an
2764 +*info source* 'script ?filename line?'+::
2765 With a single argument, returns the original source location of the given script as a list of
2766 +{filename linenumber}+. If the source location can't be determined, the
2767 list +{{} 0}+ is returned. If +'filename'+ and +'line'+ are given, returns a copy
2768 of +'script'+ with the associate source information. This can be useful to produce
2769 useful messages from `eval`, etc. if the original source information may be lost.
2771 +*info stacktrace*+::
2772 After an error is caught with `catch`, returns the stack trace as a list
2773 of +{procedure filename line \...}+.
2775 +*info statics* 'procname'+::
2776 Returns a dictionary of the static variables of procedure
2777 +'procname'+. +'procname'+ must be the name of a Tcl command
2778 procedure. An empty dictionary is returned if the procedure has
2779 no static variables.
2782 Returns the version number for this version of Jim in the form +*x.yy*+.
2784 +*info vars* ?'pattern'?+::
2785 If +'pattern'+ isn't specified,
2786 returns a list of all the names of currently-visible variables, including
2787 both locals and currently-visible globals.
2788 If +'pattern'+ is specified, only those names matching +'pattern'+
2789 are returned. Matching is determined using the same rules as for
2794 +*join* 'list ?joinString?'+
2796 The +'list'+ argument must be a valid Tcl list. This command returns the
2797 string formed by joining all of the elements of +'list'+ together with
2798 +'joinString'+ separating each adjacent pair of elements.
2800 The +'joinString'+ argument defaults to a space character.
2804 +*kill* ?'SIG'|*-0*? 'pid'+
2806 Sends the given signal to the process identified by +'pid'+.
2808 The signal may be specified by name or number in one of the following forms:
2816 The signal name may be in either upper or lower case.
2818 The special signal name +-0+ simply checks that a signal +'could'+ be sent.
2820 If no signal is specified, SIGTERM is used.
2822 An error is raised if the signal could not be delivered.
2826 +*lambda* 'args ?statics? body'+
2828 The `lambda` command is identical to `proc`, except rather than
2829 creating a named procedure, it creates an anonymous procedure and returns
2830 the name of the procedure.
2832 See `proc` and GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
2836 +*lappend* 'varName value ?value value \...?'+
2838 Treat the variable given by +'varName'+ as a list and append each of
2839 the +'value'+ arguments to that list as a separate element, with spaces
2842 If +'varName'+ doesn't exist, it is created as a list with elements given
2843 by the +'value'+ arguments. `lappend` is similar to `append` except that
2844 each +'value'+ is appended as a list element rather than raw text.
2846 This command provides a relatively efficient way to build up large lists.
2851 is much more efficient than
2853 set a [concat $a [list $b]]
2859 +*lassign* 'list varName ?varName \...?'+
2861 This command treats the value +'list'+ as a list and assigns successive elements from that list to
2862 the variables given by the +'varName'+ arguments in order. If there are more variable names than
2863 list elements, the remaining variables are set to the empty string. If there are more list elements
2864 than variables, a list of unassigned elements is returned.
2866 jim> lassign {1 2 3} a b; puts a=$a,b=$b
2872 +*local* 'cmd ?arg\...?'+
2874 First, `local` evaluates +'cmd'+ with the given arguments. The return value must
2875 be the name of an existing command, which is marked as having local scope.
2876 This means that when the current procedure exits, the specified
2877 command is deleted. This can be useful with `lambda`, local procedures or
2878 to automatically close a filehandle.
2880 In addition, if a command already exists with the same name,
2881 the existing command will be kept rather than deleted, and may be called
2882 via `upcall`. The previous command will be restored when the current
2883 procedure exits. See `upcall` for more details.
2885 In this example, a local procedure is created. Note that the procedure
2886 continues to have global scope while it is active.
2889 # proc ... returns "inner" which is marked local
2890 local proc inner {} {
2891 # will be deleted when 'outer' exits
2898 In this example, the lambda is deleted at the end of the procedure rather
2899 than waiting until garbage collection.
2902 set x [lambda inner {args} {
2903 # will be deleted when 'outer' exits
2905 # Use 'function' here which simply returns $x
2914 +*loop* 'var first limit ?incr? body'+
2916 Similar to `for` except simpler and possibly more efficient.
2917 With a positive increment, equivalent to:
2919 for {set var $first} {$var < $limit} {incr var $incr} $body
2921 If +'incr'+ is not specified, 1 is used.
2922 Note that setting the loop variable inside the loop does not
2923 affect the loop count.
2927 +*lindex* 'list ?index ...?'+
2929 Treats +'list'+ as a Tcl list and returns element +'index'+ from it
2930 (0 refers to the first element of the list).
2931 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2933 In extracting the element, +'lindex'+ observes the same rules concerning
2934 braces and quotes and backslashes as the Tcl command interpreter; however,
2935 variable substitution and command substitution do not occur.
2937 If no index values are given, simply returns +'list'+
2939 If +'index'+ is negative or greater than or equal to the number of elements
2940 in +'list'+, then an empty string is returned.
2942 If additional index arguments are supplied, then each argument is
2943 used in turn to select an element from the previous indexing
2944 operation, allowing the script to select elements from sublists.
2948 +*linsert* 'list index element ?element element \...?'+
2950 This command produces a new list from +'list'+ by inserting all
2951 of the +'element'+ arguments just before the element +'index'+
2952 of +'list'+. Each +'element'+ argument will become
2953 a separate element of the new list. If +'index'+ is less than
2954 or equal to zero, then the new elements are inserted at the
2955 beginning of the list. If +'index'+ is greater than or equal
2956 to the number of elements in the list, then the new elements are
2957 appended to the list.
2959 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2964 +*list* 'arg ?arg \...?'+
2966 This command returns a list comprised of all the arguments, +'arg'+. Braces
2967 and backslashes get added as necessary, so that the `lindex` command
2968 may be used on the result to re-extract the original arguments, and also
2969 so that `eval` may be used to execute the resulting list, with
2970 +'arg1'+ comprising the command's name and the other args comprising
2971 its arguments. `list` produces slightly different results than
2972 `concat`: `concat` removes one level of grouping before forming
2973 the list, while `list` works directly from the original arguments.
2974 For example, the command
2976 list a b {c d e} {f {g h}}
2980 a b {c d e} {f {g h}}
2982 while `concat` with the same arguments will return
2990 Treats +'list'+ as a list and returns a decimal string giving
2991 the number of elements in it.
2995 +*lset* 'varName ?index ..? newValue'+
2997 Sets an element in a list.
2999 The `lset` command accepts a parameter, +'varName'+, which it interprets
3000 as the name of a variable containing a Tcl list. It also accepts
3001 zero or more indices into the list. Finally, it accepts a new value
3002 for an element of varName. If no indices are presented, the command
3005 lset varName newValue
3007 In this case, newValue replaces the old value of the variable
3010 When presented with a single index, the `lset` command
3011 treats the content of the varName variable as a Tcl list. It addresses
3012 the index'th element in it (0 refers to the first element of the
3013 list). When interpreting the list, `lset` observes the same rules
3014 concerning braces and quotes and backslashes as the Tcl command
3015 interpreter; however, variable substitution and command substitution
3016 do not occur. The command constructs a new list in which the
3017 designated element is replaced with newValue. This new list is
3018 stored in the variable varName, and is also the return value from
3021 If index is negative or greater than or equal to the number of
3022 elements in $varName, then an error occurs.
3024 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
3026 If additional index arguments are supplied, then each argument is
3027 used in turn to address an element within a sublist designated by
3028 the previous indexing operation, allowing the script to alter
3029 elements in sublists. The command,
3033 replaces element 2 of sublist 1 with +'newValue'+.
3035 The integer appearing in each index argument must be greater than
3036 or equal to zero. The integer appearing in each index argument must
3037 be strictly less than the length of the corresponding list. In other
3038 words, the `lset` command cannot change the size of a list. If an
3039 index is outside the permitted range, an error is reported.
3044 +*lmap* 'varName list body'+
3046 +*lmap* 'varList list ?varList2 list2 \...? body'+
3048 `lmap` is a "collecting" `foreach` which returns a list of its results.
3052 jim> lmap i {1 2 3 4 5} {expr $i*$i}
3054 jim> lmap a {1 2 3} b {A B C} {list $a $b}
3057 If the body invokes `continue`, no value is added for this iteration.
3058 If the body invokes `break`, the loop ends and no more values are added.
3064 Loads the dynamic extension, +'filename'+. Generally the filename should have
3065 the extension +.so+. The initialisation function for the module must be based
3066 on the name of the file. For example loading +hwaccess.so+ will invoke
3067 the initialisation function, +Jim_hwaccessInit+. Normally the `load` command
3068 should not be used directly. Instead it is invoked automatically by `package require`.
3072 +*lrange* 'list first last'+
3074 +'list'+ must be a valid Tcl list. This command will return a new
3075 list consisting of elements +'first'+ through +'last'+, inclusive.
3077 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3079 If +'last'+ is greater than or equal to the number of elements
3080 in the list, then it is treated as if it were +end+.
3082 If +'first'+ is greater than +'last'+ then an empty string
3085 Note: +"`lrange` 'list first first'"+ does not always produce the
3086 same result as +"`lindex` 'list first'"+ (although it often does
3087 for simple fields that aren't enclosed in braces); it does, however,
3088 produce exactly the same results as +"`list` [`lindex` 'list first']"+
3093 +*lreplace* 'list first last ?element element \...?'+
3095 Returns a new list formed by replacing one or more elements of
3096 +'list'+ with the +'element'+ arguments.
3098 +'first'+ gives the index in +'list'+ of the first element
3101 If +'first'+ is less than zero then it refers to the first
3102 element of +'list'+; the element indicated by +'first'+
3103 must exist in the list.
3105 +'last'+ gives the index in +'list'+ of the last element
3106 to be replaced; it must be greater than or equal to +'first'+.
3108 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3110 The +'element'+ arguments specify zero or more new arguments to
3111 be added to the list in place of those that were deleted.
3113 Each +'element'+ argument will become a separate element of
3116 If no +'element'+ arguments are specified, then the elements
3117 between +'first'+ and +'last'+ are simply deleted.
3121 +*lrepeat* 'number element1 ?element2 \...?'+
3123 Build a list by repeating elements +'number'+ times (which must be
3124 a positive integer).
3133 Returns the list in reverse order.
3135 jim> lreverse {1 2 3}
3140 +*lsearch* '?options? list pattern'+
3142 This command searches the elements +'list'+ to see if one of them matches +'pattern'+. If so, the
3143 command returns the index of the first matching element (unless the options +-all+, +-inline+ or +-bool+ are
3144 specified.) If not, the command returns -1. The option arguments indicates how the elements of
3145 the list are to be matched against pattern and must have one of the values below:
3147 *Note* that this command is different from Tcl in that default match type is +-exact+ rather than +-glob+.
3150 +'pattern'+ is a literal string that is compared for exact equality against each list element.
3151 This is the default.
3154 +'pattern'+ is a glob-style pattern which is matched against each list element using the same
3155 rules as the string match command.
3158 +'pattern'+ is treated as a regular expression and matched against each list element using
3159 the rules described by `regexp`.
3161 +*-command* 'cmdname'+::
3162 +'cmdname'+ is a command which is used to match the pattern against each element of the
3163 list. It is invoked as +'cmdname' ?*-nocase*? 'pattern listvalue'+ and should return 1
3164 for a match, or 0 for no match.
3167 Changes the result to be the list of all matching indices (or all matching values if
3168 +-inline+ is specified as well). If indices are returned, the indices will be in numeric
3169 order. If values are returned, the order of the values will be the order of those values
3170 within the input list.
3173 The matching value is returned instead of its index (or an empty string if no value
3174 matches). If +-all+ is also specified, then the result of the command is the list of all
3175 values that matched. The +-inline+ and +-bool+ options are mutually exclusive.
3178 Changes the result to '1' if a match was found, or '0' otherwise. If +-all+ is also specified,
3179 the result will be a list of '0' and '1' for each element of the list depending upon whether
3180 the corresponding element matches. The +-inline+ and +-bool+ options are mutually exclusive.
3183 This negates the sense of the match, returning the index (or value
3184 if +-inline+ is specified) of the first non-matching value in the
3185 list. If +-bool+ is also specified, the '0' will be returned if a
3186 match is found, or '1' otherwise. If +-all+ is also specified,
3187 non-matches will be returned rather than matches.
3190 Causes comparisons to be handled in a case-insensitive manner.
3194 +*lsort* ?*-index* 'listindex'? ?*-nocase|-integer|-real|-command* 'cmdname'? ?*-unique*? ?*-decreasing*|*-increasing*? 'list'+
3196 Sort the elements of +'list'+, returning a new list in sorted order.
3197 By default, ASCII (or UTF-8) sorting is used, with the result in increasing order.
3199 If +-nocase+ is specified, comparisons are case-insensitive.
3201 If +-integer+ is specified, numeric sorting is used.
3203 If +-real+ is specified, floating point number sorting is used.
3205 If +-command 'cmdname'+ is specified, +'cmdname'+ is treated as a command
3206 name. For each comparison, +'cmdname $value1 $value2+' is called which
3207 should compare the values and return an integer less than, equal
3208 to, or greater than zero if the +'$value1'+ is to be considered less
3209 than, equal to, or greater than +'$value2'+, respectively.
3211 If +-decreasing+ is specified, the resulting list is in the opposite
3212 order to what it would be otherwise. +-increasing+ is the default.
3214 If +-unique+ is specified, then only the last set of duplicate elements found in the list will be retained.
3215 Note that duplicates are determined relative to the comparison used in the sort. Thus if +-index 0+ is used,
3216 +{1 a}+ and +{1 b}+ would be considered duplicates and only the second element, +{1 b}+, would be retained.
3218 If +-index 'listindex'+ is specified, each element of the list is treated as a list and
3219 the given index is extracted from the list for comparison. The list index may
3220 be any valid list index, such as +1+, +end+ or +end-2+.
3224 +*open* 'fileName ?access?'+
3226 +*open* '|command-pipeline ?access?'+
3228 Opens a file and returns an identifier
3229 that may be used in future invocations
3230 of commands like `read`, `puts`, and `close`.
3231 +'fileName'+ gives the name of the file to open.
3233 The +'access'+ argument indicates the way in which the file is to be accessed.
3234 It may have any of the following values:
3237 Open the file for reading only; the file must already exist.
3240 Open the file for both reading and writing; the file must
3244 Open the file for writing only. Truncate it if it exists. If it doesn't
3245 exist, create a new file.
3248 Open the file for reading and writing. Truncate it if it exists.
3249 If it doesn't exist, create a new file.
3252 Open the file for writing only. The file must already exist, and the file
3253 is positioned so that new data is appended to the file.
3256 Open the file for reading and writing. If the file doesn't
3257 exist, create a new empty file. Set the initial access position
3258 to the end of the file.
3260 +'access'+ defaults to 'r'.
3262 If a file is opened for both reading and writing, then `seek`
3263 must be invoked between a read and a write, or vice versa.
3265 If the first character of +'fileName'+ is "|" then the remaining
3266 characters of +'fileName'+ are treated as a list of arguments that
3267 describe a command pipeline to invoke, in the same style as the
3268 arguments for exec. In this case, the channel identifier returned
3269 by open may be used to write to the command's input pipe or read
3270 from its output pipe, depending on the value of +'access'+. If write-only
3271 access is used (e.g. +'access'+ is 'w'), then standard output for the
3272 pipeline is directed to the current standard output unless overridden
3273 by the command. If read-only access is used (e.g. +'access'+ is r),
3274 standard input for the pipeline is taken from the current standard
3275 input unless overridden by the command.
3277 The `pid` command may be used to return the process ids of the commands
3278 forming the command pipeline.
3280 See also `socket`, `pid`, `exec`
3284 +*package provide* 'name ?version?'+
3286 Indicates that the current script provides the package named +'name'+.
3287 If no version is specified, '1.0' is used.
3289 Any script which provides a package may include this statement
3290 as the first statement, although it is not required.
3292 +*package require* 'name ?version?'*+
3294 Searches for the package with the given +'name'+ by examining each path
3295 in '$::auto_path' and trying to load '$path/$name.so' as a dynamic extension,
3296 or '$path/$name.tcl' as a script package.
3298 The first such file which is found is considered to provide the package.
3299 (The version number is ignored).
3301 If '$name.so' exists, it is loaded with the `load` command,
3302 otherwise if '$name.tcl' exists it is loaded with the `source` command.
3304 If `load` or `source` fails, `package require` will fail immediately.
3305 No further attempt will be made to locate the file.
3313 The first form returns the process identifier of the current process.
3315 The second form accepts a handle returned by `open` and returns a list
3316 of the process ids forming the pipeline in the same form as `exec ... &`.
3317 If 'fileId' represents a regular file handle rather than a command pipeline,
3318 the empty string is returned instead.
3320 See also `open`, `exec`
3324 +*proc* 'name args ?statics? body'+
3326 The `proc` command creates a new Tcl command procedure, +'name'+.
3327 When the new command is invoked, the contents of +'body'+ will be executed.
3328 Tcl interpreter. +'args'+ specifies the formal arguments to the procedure.
3329 If specified, +'statics'+, declares static variables which are bound to the
3332 See PROCEDURES for detailed information about Tcl procedures.
3334 The `proc` command returns +'name'+ (which is useful with `local`).
3336 When a procedure is invoked, the procedure's return value is the
3337 value specified in a `return` command. If the procedure doesn't
3338 execute an explicit `return`, then its return value is the value
3339 of the last command executed in the procedure's body.
3341 If an error occurs while executing the procedure body, then the
3342 procedure-as-a-whole will return that same error.
3346 +*puts* ?*-nonewline*? '?fileId? string'+
3348 +'fileId' *puts* ?*-nonewline*? 'string'+
3350 Writes the characters given by +'string'+ to the file given
3351 by +'fileId'+. +'fileId'+ must have been the return
3352 value from a previous call to `open`, or it may be
3353 +stdout+ or +stderr+ to refer to one of the standard I/O
3354 channels; it must refer to a file that was opened for
3357 In the first form, if no +'fileId'+ is specified then it defaults to +stdout+.
3358 `puts` normally outputs a newline character after +'string'+,
3359 but this feature may be suppressed by specifying the +-nonewline+
3362 Output to files is buffered internally by Tcl; the `flush`
3363 command may be used to force buffered characters to be output.
3369 Returns the path name of the current working directory.
3373 +*rand* '?min? ?max?'+
3375 Returns a random integer between +'min'+ (defaults to 0) and +'max'+
3376 (defaults to the maximum integer).
3378 If only one argument is given, it is interpreted as +'max'+.
3382 +*range* '?start? end ?step?'+
3384 Returns a list of integers starting at +'start'+ (defaults to 0)
3385 and ranging up to but not including +'end'+ in steps of +'step'+ defaults to 1).
3398 +*read* ?*-nonewline*? 'fileId'+
3400 +'fileId' *read* ?*-nonewline*?+
3402 +*read* 'fileId numBytes'+
3404 +'fileId' *read* 'numBytes'+
3407 In the first form, all of the remaining bytes are read from the file
3408 given by +'fileId'+; they are returned as the result of the command.
3409 If the +-nonewline+ switch is specified then the last
3410 character of the file is discarded if it is a newline.
3412 In the second form, the extra argument specifies how many bytes to read;
3413 exactly this many bytes will be read and returned, unless there are fewer than
3414 +'numBytes'+ bytes left in the file; in this case, all the remaining
3417 +'fileId'+ must be +stdin+ or the return value from a previous call
3418 to `open`; it must refer to a file that was opened for reading.
3422 +*regexp ?-nocase? ?-line? ?-indices? ?-start* 'offset'? *?-all? ?-inline? ?--?* 'exp string ?matchVar? ?subMatchVar subMatchVar \...?'+
3424 Determines whether the regular expression +'exp'+ matches part or
3425 all of +'string'+ and returns 1 if it does, 0 if it doesn't.
3427 See REGULAR EXPRESSIONS above for complete information on the
3428 syntax of +'exp'+ and how it is matched against +'string'+.
3430 If additional arguments are specified after +'string'+ then they
3431 are treated as the names of variables to use to return
3432 information about which part(s) of +'string'+ matched +'exp'+.
3433 +'matchVar'+ will be set to the range of +'string'+ that
3434 matched all of +'exp'+. The first +'subMatchVar'+ will contain
3435 the characters in +'string'+ that matched the leftmost parenthesized
3436 subexpression within +'exp'+, the next +'subMatchVar'+ will
3437 contain the characters that matched the next parenthesized
3438 subexpression to the right in +'exp'+, and so on.
3440 Normally, +'matchVar'+ and the each +'subMatchVar'+ are set to hold the
3441 matching characters from `string`, however see +-indices+ and
3444 If there are more values for +'subMatchVar'+ than parenthesized subexpressions
3445 within +'exp'+, or if a particular subexpression in +'exp'+ doesn't
3446 match the string (e.g. because it was in a portion of the expression
3447 that wasn't matched), then the corresponding +'subMatchVar'+ will be
3448 set to +"-1 -1"+ if +-indices+ has been specified or to an empty
3451 The following switches modify the behaviour of +'regexp'+
3454 Causes upper-case and lower-case characters to be treated as
3455 identical during the matching process.
3458 Use newline-sensitive matching. By default, newline
3459 is a completely ordinary character with no special meaning in
3460 either REs or strings. With this flag, +[^+ bracket expressions
3461 and +.+ never match newline, an +^+ anchor matches the null
3462 string after any newline in the string in addition to its normal
3463 function, and the +$+ anchor matches the null string before any
3464 newline in the string in addition to its normal function.
3467 Changes what is stored in the subMatchVars. Instead of
3468 storing the matching characters from string, each variable
3469 will contain a list of two decimal strings giving the indices
3470 in string of the first and last characters in the matching
3471 range of characters.
3473 +*-start* 'offset'+::
3474 Specifies a character index offset into the string at which to start
3475 matching the regular expression. If +-indices+ is
3476 specified, the indices will be indexed starting from the
3477 absolute beginning of the input string. +'offset'+ will be
3478 constrained to the bounds of the input string.
3481 Causes the regular expression to be matched as many times as possible
3482 in the string, returning the total number of matches found. If this
3483 is specified with match variables, they will contain information
3484 for the last match only.
3487 Causes the command to return, as a list, the data that would otherwise
3488 be placed in match variables. When using +-inline+, match variables
3489 may not be specified. If used with +-all+, the list will be concatenated
3490 at each iteration, such that a flat list is always returned. For
3491 each match iteration, the command will append the overall match
3492 data, plus one element for each subexpression in the regular
3496 Marks the end of switches. The argument following this one will be
3497 treated as +'exp'+ even if it starts with a +-+.
3501 +*regsub ?-nocase? ?-all? ?-line? ?-start* 'offset'? ?*--*? 'exp string subSpec ?varName?'+
3503 This command matches the regular expression +'exp'+ against
3504 +'string'+ using the rules described in REGULAR EXPRESSIONS
3507 If +'varName'+ is specified, the commands stores +'string'+ to +'varName'+
3508 with the substitutions detailed below, and returns the number of
3509 substitutions made (normally 1 unless +-all+ is specified).
3510 This is 0 if there were no matches.
3512 If +'varName'+ is not specified, the substituted string will be returned
3515 When copying +'string'+, the portion of +'string'+ that
3516 matched +'exp'+ is replaced with +'subSpec'+.
3517 If +'subSpec'+ contains a +&+ or +{backslash}0+, then it is replaced
3518 in the substitution with the portion of +'string'+ that
3521 If +'subSpec'+ contains a +{backslash}n+, where +'n'+ is a digit
3522 between 1 and 9, then it is replaced in the substitution with
3523 the portion of +'string'+ that matched the +'n'+\'-th
3524 parenthesized subexpression of +'exp'+.
3525 Additional backslashes may be used in +'subSpec'+ to prevent special
3526 interpretation of +&+ or +{backslash}0+ or +{backslash}n+ or
3529 The use of backslashes in +'subSpec'+ tends to interact badly
3530 with the Tcl parser's use of backslashes, so it's generally
3531 safest to enclose +'subSpec'+ in braces if it includes
3534 The following switches modify the behaviour of +'regsub'+
3537 Upper-case characters in +'string'+ are converted to lower-case
3538 before matching against +'exp'+; however, substitutions
3539 specified by +'subSpec'+ use the original unconverted form
3543 All ranges in +'string'+ that match +'exp'+ are found and substitution
3544 is performed for each of these ranges, rather than only the
3545 first. The +&+ and +{backslash}n+ sequences are handled for
3546 each substitution using the information from the corresponding
3550 Use newline-sensitive matching. By default, newline
3551 is a completely ordinary character with no special meaning in
3552 either REs or strings. With this flag, +[^+ bracket expressions
3553 and +.+ never match newline, an +^+ anchor matches the null
3554 string after any newline in the string in addition to its normal
3555 function, and the +$+ anchor matches the null string before any
3556 newline in the string in addition to its normal function.
3558 +*-start* 'offset'+::
3559 Specifies a character index offset into the string at which to
3560 start matching the regular expression. +'offset'+ will be
3561 constrained to the bounds of the input string.
3564 Marks the end of switches. The argument following this one will be
3565 treated as +'exp'+ even if it starts with a +-+.
3569 +*ref* 'string tag ?finalizer?'+
3571 Create a new reference containing +'string'+ of type +'tag'+.
3572 If +'finalizer'+ is specified, it is a command which will be invoked
3573 when the a garbage collection cycle runs and this reference is
3574 no longer accessible.
3576 The finalizer is invoked as:
3578 finalizer reference string
3580 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
3584 +*rename* 'oldName newName'+
3586 Rename the command that used to be called +'oldName'+ so that it
3587 is now called +'newName'+. If +'newName'+ is an empty string
3588 (e.g. {}) then +'oldName'+ is deleted. The `rename` command
3589 returns an empty string as result.
3593 +*return* ?*-code* 'code'? ?*-errorinfo* 'stacktrace'? ?*-errorcode* 'errorcode'? ?*-level* 'n'? ?'value'?+
3595 Return immediately from the current procedure (or top-level command
3596 or `source` command), with +'value'+ as the return value. If +'value'+
3597 is not specified, an empty string will be returned as result.
3599 If +-code+ is specified (as either a number or ok, error, break,
3600 continue, signal, return or exit), this code will be used instead
3601 of +JIM_OK+. This is generally useful when implementing flow of control
3604 If +-level+ is specified and greater than 1, it has the effect of delaying
3605 the new return code from +-code+. This is useful when rethrowing an error
3606 from `catch`. See the implementation of try/catch in tclcompat.tcl for
3607 an example of how this is done.
3609 Note: The following options are only used when +-code+ is JIM_ERR.
3611 If +-errorinfo+ is specified (as returned from `info stacktrace`)
3612 it is used to initialize the stacktrace.
3614 If +-errorcode+ is specified, it is used to set the global variable $::errorCode.
3618 +*scan* 'string format varName1 ?varName2 \...?'+
3620 This command parses fields from an input string in the same fashion
3621 as the C 'sscanf' procedure. +'string'+ gives the input to be parsed
3622 and +'format'+ indicates how to parse it, using '%' fields as in
3623 'sscanf'. All of the 'sscanf' options are valid; see the 'sscanf'
3624 man page for details. Each +'varName'+ gives the name of a variable;
3625 when a field is scanned from +'string'+, the result is converted back
3626 into a string and assigned to the corresponding +'varName'+. The
3627 only unusual conversion is for '%c'. For '%c' conversions a single
3628 character value is converted to a decimal string, which is then
3629 assigned to the corresponding +'varName'+; no field width may be
3630 specified for this conversion.
3634 +*seek* 'fileId offset ?origin?'+
3636 +'fileId' *seek* 'offset ?origin?'+
3638 Change the current access position for +'fileId'+.
3639 The +'offset'+ and +'origin'+ arguments specify the position at
3640 which the next read or write will occur for +'fileId'+.
3641 +'offset'+ must be a number (which may be negative) and +'origin'+
3642 must be one of the following:
3645 The new access position will be +'offset'+ bytes from the start
3649 The new access position will be +'offset'+ bytes from the current
3650 access position; a negative +'offset'+ moves the access position
3651 backwards in the file.
3654 The new access position will be +'offset'+ bytes from the end of
3655 the file. A negative +'offset'+ places the access position before
3656 the end-of-file, and a positive +'offset'+ places the access position
3657 after the end-of-file.
3659 The +'origin'+ argument defaults to +start+.
3661 +'fileId'+ must have been the return value from a previous call to
3662 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
3663 of the standard I/O channels.
3665 This command returns an empty string.
3669 +*set* 'varName ?value?'+
3671 Returns the value of variable +'varName'+.
3673 If +'value'+ is specified, then set the value of +'varName'+ to +'value'+,
3674 creating a new variable if one doesn't already exist, and return
3677 If +'varName'+ contains an open parenthesis and ends with a
3678 close parenthesis, then it refers to an array element: the characters
3679 before the open parenthesis are the name of the array, and the characters
3680 between the parentheses are the index within the array.
3681 Otherwise +'varName'+ refers to a scalar variable.
3683 If no procedure is active, then +'varName'+ refers to a global
3686 If a procedure is active, then +'varName'+ refers to a parameter
3687 or local variable of the procedure, unless the +'global'+ command
3688 has been invoked to declare +'varName'+ to be global.
3690 The +::+ prefix may also be used to explicitly reference a variable
3691 in the global scope.
3695 +*setref* 'reference string'+
3697 Store a new string in +'reference'+, replacing the existing string.
3698 The reference must be a valid reference create with the `ref`
3701 See GARBAGE COLLECTION, REFERENCES, LAMBDA FUNCTION for more detail.
3705 Command for signal handling.
3707 See `kill` for the different forms which may be used to specify signals.
3709 Commands which return a list of signal names do so using the canonical form:
3712 +*signal handle* ?'signals \...'?+::
3713 If no signals are given, returns a list of all signals which are currently
3715 If signals are specified, these are added to the list of signals currently
3718 +*signal ignore* ?'signals \...'?+::
3719 If no signals are given, returns a lists all signals which are currently
3721 If signals are specified, these are added to the list of signals
3722 currently being ignored. These signals are still delivered, but
3723 are not considered by `catch -signal` or `try -signal`. Use
3724 `signal check` to determine which signals have occurred but
3727 +*signal default* ?'signals \...'?+::
3728 If no signals are given, returns a lists all signals which are currently have
3729 the default behaviour.
3730 If signals are specified, these are added to the list of signals which have
3731 the default behaviour.
3733 +*signal check ?-clear?* ?'signals \...'?+::
3734 Returns a list of signals which have been delivered to the process
3735 but are 'ignored'. If signals are specified, only that set of signals will
3736 be checked, otherwise all signals will be checked.
3737 If +-clear+ is specified, any signals returned are removed and will not be
3738 returned by subsequent calls to `signal check` unless delivered again.
3740 +*signal throw* ?'signal'?+::
3741 Raises the given signal, which defaults to +SIGINT+ if not specified.
3742 The behaviour is identical to:
3746 Note that `signal handle` and `signal ignore` represent two forms of signal
3747 handling. `signal handle` is used in conjunction with `catch -signal` or `try -signal`
3748 to immediately abort execution when the signal is delivered. Alternatively, `signal ignore`
3749 is used in conjunction with `signal check` to handle signal synchronously. Consider the
3752 Prevent a processing from taking too long
3754 signal handle SIGALRM
3757 .. possibly long running process ..
3760 puts stderr "Process took too long"
3763 Handle SIGHUP to reconfigure:
3765 signal ignore SIGHUP
3767 ... handle configuration/reconfiguration ...
3768 while {[signal check -clear SIGHUP] eq ""} {
3769 ... do processing ..
3771 # Received SIGHUP, so reconfigure
3778 Pauses for the given number of seconds, which may be a floating
3779 point value less than one to sleep for less than a second, or an
3780 integer to sleep for one or more seconds.
3784 +*source* 'fileName'+
3786 Read file +'fileName'+ and pass the contents to the Tcl interpreter
3787 as a sequence of commands to execute in the normal fashion. The return
3788 value of `source` is the return value of the last command executed
3789 from the file. If an error occurs in executing the contents of the
3790 file, then the `source` command will return that error.
3792 If a `return` command is invoked from within the file, the remainder of
3793 the file will be skipped and the `source` command will return
3794 normally with the result from the `return` command.
3798 +*split* 'string ?splitChars?'+
3800 Returns a list created by splitting +'string'+ at each character
3801 that is in the +'splitChars'+ argument.
3803 Each element of the result list will consist of the
3804 characters from +'string'+ between instances of the
3805 characters in +'splitChars'+.
3807 Empty list elements will be generated if +'string'+ contains
3808 adjacent characters in +'splitChars'+, or if the first or last
3809 character of +'string'+ is in +'splitChars'+.
3811 If +'splitChars'+ is an empty string then each character of
3812 +'string'+ becomes a separate element of the result list.
3814 +'splitChars'+ defaults to the standard white-space characters.
3817 split "comp.unix.misc" .
3819 returns +'"comp unix misc"'+ and
3821 split "Hello world" {}
3823 returns +'"H e l l o { } w o r l d"'+.
3828 +*stackdump* 'stacktrace'+
3830 Creates a human readable representation of a stack trace.
3837 Returns a live stack trace as a list of +proc file line proc file line \...+.
3838 Iteratively uses `info frame` to create the stack trace. This stack trace is in the
3839 same form as produced by `catch` and `info stacktrace`
3841 See also `stackdump`.
3846 +*string* 'option arg ?arg \...?'+
3848 Perform one of several string operations, depending on +'option'+.
3849 The legal options (which may be abbreviated) are:
3851 +*string bytelength* 'string'+::
3852 Returns the length of the string in bytes. This will return
3853 the same value as `string length` if UTF-8 support is not enabled,
3854 or if the string is composed entirely of ASCII characters.
3855 See UTF-8 AND UNICODE.
3857 +*string byterange* 'string first last'+::
3858 Like `string range` except works on bytes rather than characters.
3859 These commands are identical if UTF-8 support is not enabled.
3861 +*string cat* '?string1 string2 \...?'+::
3862 Concatenates the given strings into a single string.
3864 +*string compare ?-nocase?* ?*-length* 'len? string1 string2'+::
3865 Perform a character-by-character comparison of strings +'string1'+ and
3866 +'string2'+ in the same way as the C 'strcmp' procedure. Return
3867 -1, 0, or 1, depending on whether +'string1'+ is lexicographically
3868 less than, equal to, or greater than +'string2'+. If +-length+
3869 is specified, then only the first +'len'+ characters are used
3870 in the comparison. If +'len'+ is negative, it is ignored.
3871 Performs a case-insensitive comparison if +-nocase+ is specified.
3873 +*string equal ?-nocase?* '?*-length* len?' 'string1 string2'+::
3874 Returns 1 if the strings are equal, or 0 otherwise. If +-length+
3875 is specified, then only the first +'len'+ characters are used
3876 in the comparison. If +'len'+ is negative, it is ignored.
3877 Performs a case-insensitive comparison if +-nocase+ is specified.
3879 +*string first* 'string1 string2 ?firstIndex?'+::
3880 Search +'string2'+ for a sequence of characters that exactly match
3881 the characters in +'string1'+. If found, return the index of the
3882 first character in the first such match within +'string2'+. If not
3883 found, return -1. If +'firstIndex'+ is specified, matching will start
3884 from +'firstIndex'+ of +'string1'+.
3886 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'firstIndex'+.
3888 +*string index* 'string charIndex'+::
3889 Returns the +'charIndex'+'th character of the +'string'+
3890 argument. A +'charIndex'+ of 0 corresponds to the first
3891 character of the string.
3892 If +'charIndex'+ is less than 0 or greater than
3893 or equal to the length of the string then an empty string is
3896 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'charIndex'+.
3898 +*string is* 'class' ?*-strict*? 'string'+::
3899 Returns 1 if +'string'+ is a valid member of the specified character
3900 class, otherwise returns 0. If +-strict+ is specified, then an
3901 empty string returns 0, otherwise an empty string will return 1
3902 on any class. The following character classes are recognized
3903 (the class name can be abbreviated):
3905 +alnum+;; Any alphabet or digit character.
3906 +alpha+;; Any alphabet character.
3907 +ascii+;; Any character with a value less than 128 (those that are in the 7-bit ascii range).
3908 +control+;; Any control character.
3909 +digit+;; Any digit character.
3910 +double+;; Any of the valid forms for a double in Tcl, with optional surrounding whitespace.
3911 In case of under/overflow in the value, 0 is returned.
3912 +graph+;; Any printing character, except space.
3913 +integer+;; Any of the valid string formats for an integer value in Tcl, with optional surrounding whitespace.
3914 +lower+;; Any lower case alphabet character.
3915 +print+;; Any printing character, including space.
3916 +punct+;; Any punctuation character.
3917 +space+;; Any space character.
3918 +upper+;; Any upper case alphabet character.
3919 +xdigit+;; Any hexadecimal digit character ([0-9A-Fa-f]).
3921 Note that string classification does +'not'+ respect UTF-8. See UTF-8 AND UNICODE
3923 +*string last* 'string1 string2 ?lastIndex?'+::
3924 Search +'string2'+ for a sequence of characters that exactly match
3925 the characters in +'string1'+. If found, return the index of the
3926 first character in the last such match within +'string2'+. If there
3927 is no match, then return -1. If +'lastIndex'+ is specified, only characters
3928 up to +'lastIndex'+ of +'string2'+ will be considered in the match.
3930 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'lastIndex'+.
3932 +*string length* 'string'+::
3933 Returns a decimal string giving the number of characters in +'string'+.
3934 If UTF-8 support is enabled, this may be different than the number of bytes.
3935 See UTF-8 AND UNICODE
3937 +*string map ?-nocase?* 'mapping string'+::
3938 Replaces substrings in +'string'+ based on the key-value pairs in
3939 +'mapping'+, which is a list of +key value key value \...+ as in the form
3940 returned by `array get`. Each instance of a key in the string will be
3941 replaced with its corresponding value. If +-nocase+ is specified, then
3942 matching is done without regard to case differences. Both key and value may
3943 be multiple characters. Replacement is done in an ordered manner, so the
3944 key appearing first in the list will be checked first, and so on. +'string'+ is
3945 only iterated over once, so earlier key replacements will have no affect for
3946 later key matches. For example,
3948 string map {abc 1 ab 2 a 3 1 0} 1abcaababcabababc
3951 will return the string +01321221+.
3953 Note that if an earlier key is a prefix of a later one, it will completely mask the later
3954 one. So if the previous example is reordered like this,
3956 string map {1 0 ab 2 a 3 abc 1} 1abcaababcabababc
3959 it will return the string +02c322c222c+.
3961 +*string match ?-nocase?* 'pattern string'+::
3962 See if +'pattern'+ matches +'string'+; return 1 if it does, 0
3963 if it doesn't. Matching is done in a fashion similar to that
3964 used by the C-shell. For the two strings to match, their contents
3965 must be identical except that the following special sequences
3966 may appear in +'pattern'+:
3969 Matches any sequence of characters in +'string'+,
3970 including a null string.
3973 Matches any single character in +'string'+.
3976 Matches any character in the set given by +'chars'+.
3977 If a sequence of the form +'x-y'+ appears in +'chars'+,
3978 then any character between +'x'+ and +'y'+, inclusive,
3982 Matches the single character +'x'+. This provides a way of
3983 avoiding the special interpretation of the characters +{backslash}*?[]+
3986 Performs a case-insensitive comparison if +-nocase+ is specified.
3988 +*string range* 'string first last'+::
3989 Returns a range of consecutive characters from +'string'+, starting
3990 with the character whose index is +'first'+ and ending with the
3991 character whose index is +'last'+. An index of 0 refers to the
3992 first character of the string.
3994 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3996 If +'first'+ is less than zero then it is treated as if it were zero, and
3997 if +'last'+ is greater than or equal to the length of the string then
3998 it is treated as if it were +end+. If +'first'+ is greater than
3999 +'last'+ then an empty string is returned.
4001 +*string repeat* 'string count'+::
4002 Returns a new string consisting of +'string'+ repeated +'count'+ times.
4004 +*string replace* 'string first last ?newstring?'+::
4005 Removes a range of consecutive characters from +'string'+, starting
4006 with the character whose index is +'first'+ and ending with the
4007 character whose index is +'last'+. If +'newstring'+ is specified,
4008 then it is placed in the removed character range. If +'first'+ is
4009 less than zero then it is treated as if it were zero, and if +'last'+
4010 is greater than or equal to the length of the string then it is
4011 treated as if it were +end+. If +'first'+ is greater than +'last'+
4012 or the length of the initial string, or +'last'+ is less than 0,
4013 then the initial string is returned untouched.
4015 +*string reverse* 'string'+::
4016 Returns a string that is the same length as +'string'+ but
4017 with its characters in the reverse order.
4019 +*string tolower* 'string'+::
4020 Returns a value equal to +'string'+ except that all upper case
4021 letters have been converted to lower case.
4023 +*string totitle* 'string'+::
4024 Returns a value equal to +'string'+ except that the first character
4025 is converted to title case (or upper case if there is no UTF-8 titlecase variant)
4026 and all remaining characters have been converted to lower case.
4028 +*string toupper* 'string'+::
4029 Returns a value equal to +'string'+ except that all lower case
4030 letters have been converted to upper case.
4032 +*string trim* 'string ?chars?'+::
4033 Returns a value equal to +'string'+ except that any leading
4034 or trailing characters from the set given by +'chars'+ are
4036 If +'chars'+ is not specified then white space is removed
4037 (spaces, tabs, newlines, and carriage returns).
4039 +*string trimleft* 'string ?chars?'+::
4040 Returns a value equal to +'string'+ except that any
4041 leading characters from the set given by +'chars'+ are
4043 If +'chars'+ is not specified then white space is removed
4044 (spaces, tabs, newlines, and carriage returns).
4046 +*string trimright* 'string ?chars?'+::
4047 Returns a value equal to +'string'+ except that any
4048 trailing characters from the set given by +'chars'+ are
4050 If +'chars'+ is not specified then white space is removed
4051 (spaces, tabs, newlines, and carriage returns).
4052 Null characters are always removed.
4056 +*subst ?-nobackslashes? ?-nocommands? ?-novariables?* 'string'+
4058 This command performs variable substitutions, command substitutions,
4059 and backslash substitutions on its string argument and returns the
4060 fully-substituted result. The substitutions are performed in exactly
4061 the same way as for Tcl commands. As a result, the string argument
4062 is actually substituted twice, once by the Tcl parser in the usual
4063 fashion for Tcl commands, and again by the subst command.
4065 If any of the +-nobackslashes+, +-nocommands+, or +-novariables+ are
4066 specified, then the corresponding substitutions are not performed.
4067 For example, if +-nocommands+ is specified, no command substitution
4068 is performed: open and close brackets are treated as ordinary
4069 characters with no special interpretation.
4071 *Note*: when it performs its substitutions, subst does not give any
4072 special treatment to double quotes or curly braces. For example,
4073 the following script returns +xyz \{44\}+, not +xyz \{$a\}+.
4081 +*switch* '?options? string pattern body ?pattern body \...?'+
4083 +*switch* '?options? string {pattern body ?pattern body \...?}'+
4085 The `switch` command matches its string argument against each of
4086 the pattern arguments in order. As soon as it finds a pattern that
4087 matches string it evaluates the following body and returns the
4088 result of that evaluation. If the last pattern argument is default
4089 then it matches anything. If no pattern argument matches string and
4090 no default is given, then the `switch` command returns an empty string.
4091 If the initial arguments to switch start with - then they are treated
4092 as options. The following options are currently supported:
4095 Use exact matching when comparing string to a
4096 pattern. This is the default.
4099 When matching string to the patterns, use glob-style
4100 matching (i.e. the same as implemented by the string
4104 When matching string to the patterns, use regular
4105 expression matching (i.e. the same as implemented
4106 by the regexp command).
4108 +-command 'commandname'+::
4109 When matching string to the patterns, use the given command, which
4110 must be a single word. The command is invoked as
4111 'commandname pattern string', or 'commandname -nocase pattern string'
4112 and must return 1 if matched, or 0 if not.
4115 Marks the end of options. The argument following
4116 this one will be treated as string even if it starts
4119 Two syntaxes are provided for the pattern and body arguments. The
4120 first uses a separate argument for each of the patterns and commands;
4121 this form is convenient if substitutions are desired on some of the
4122 patterns or commands. The second form places all of the patterns
4123 and commands together into a single argument; the argument must
4124 have proper list structure, with the elements of the list being the
4125 patterns and commands. The second form makes it easy to construct
4126 multi-line `switch` commands, since the braces around the whole list
4127 make it unnecessary to include a backslash at the end of each line.
4128 Since the pattern arguments are in braces in the second form, no
4129 command or variable substitutions are performed on them; this makes
4130 the behaviour of the second form different than the first form in
4133 If a body is specified as +-+ it means that the body for the next
4134 pattern should also be used as the body for this pattern (if the
4135 next pattern also has a body of +-+ then the body after that is
4136 used, and so on). This feature makes it possible to share a single
4137 body among several patterns.
4139 Below are some examples of `switch` commands:
4141 switch abc a - b {format 1} abc {format 2} default {format 3}
4145 switch -regexp aaab {
4165 +*tailcall* 'cmd ?arg\...?'+
4167 The `tailcall` command provides an optimised way of invoking a command whilst replacing
4168 the current call frame. This is similar to 'exec' in Bourne Shell.
4170 The following are identical except the first immediately replaces the current call frame.
4174 return [uplevel 1 [list a b c]]
4176 `tailcall` is useful as a dispatch mechanism:
4179 tailcall sub_$cmd {*}$args
4190 Returns a decimal string giving the current access position in
4193 +'fileId'+ must have been the return value from a previous call to
4194 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
4195 of the standard I/O channels.
4199 +*throw* 'code ?msg?'+
4201 This command throws an exception (return) code along with an optional message.
4202 This command is mostly for convenient usage with `try`.
4204 The command +throw break+ is equivalent to +break+.
4205 The command +throw 20 message+ can be caught with an +on 20 \...+ clause to `try`.
4209 +*time* 'command ?count?'+
4211 This command will call the Tcl interpreter +'count'+
4212 times to execute +'command'+ (or once if +'count'+ isn't
4213 specified). It will then return a string of the form
4215 503 microseconds per iteration
4217 which indicates the average amount of time required per iteration,
4220 Time is measured in elapsed time, not CPU time.
4224 +*try* '?catchopts? tryscript' ?*on* 'returncodes {?resultvar? ?optsvar?} handlerscript \...'? ?*finally* 'finalscript'?+
4226 The `try` command is provided as a convenience for exception handling.
4228 This interpeter first evaluates +'tryscript'+ under the effect of the catch
4229 options +'catchopts'+ (e.g. +-signal -noexit --+, see `catch`).
4231 It then evaluates the script for the first matching 'on' handler
4232 (there many be zero or more) based on the return code from the `try`
4233 section. For example a normal +JIM_ERR+ error will be matched by
4234 an 'on error' handler.
4236 Finally, any +'finalscript'+ is evaluated.
4238 The result of this command is the result of +'tryscript'+, except in the
4239 case where an exception occurs in a matching 'on' handler script or the 'finally' script,
4240 in which case the result is this new exception.
4242 The specified +'returncodes'+ is a list of return codes either as names ('ok', 'error', 'break', etc.)
4245 If +'resultvar'+ and +'optsvar'+ are specified, they are set as for `catch` before evaluating
4246 the matching handler.
4253 } on {continue break} {} {
4254 error "Unexpected break/continue"
4255 } on error {msg opts} {
4256 puts "Dealing with error"
4257 return {*}$opts $msg
4259 puts "Got signal: $sig"
4264 If break, continue or error are raised, they are dealt with by the matching
4267 In any case, the file will be closed via the 'finally' clause.
4269 See also `throw`, `catch`, `return`, `error`.
4273 +*unknown* 'cmdName ?arg arg ...?'+
4275 This command doesn't actually exist as part of Tcl, but Tcl will
4276 invoke it if it does exist.
4278 If the Tcl interpreter encounters a command name for which there
4279 is not a defined command, then Tcl checks for the existence of
4280 a command named `unknown`.
4282 If there is no such command, then the interpreter returns an
4285 If the `unknown` command exists, then it is invoked with
4286 arguments consisting of the fully-substituted name and arguments
4287 for the original non-existent command.
4289 The `unknown` command typically does things like searching
4290 through library directories for a command procedure with the name
4291 +'cmdName'+, or expanding abbreviated command names to full-length,
4292 or automatically executing unknown commands as UNIX sub-processes.
4294 In some cases (such as expanding abbreviations) `unknown` will
4295 change the original command slightly and then (re-)execute it.
4296 The result of the `unknown` command is used as the result for
4297 the original non-existent command.
4301 +*unset ?-nocomplain? ?--?* '?name name ...?'+
4304 Each +'name'+ is a variable name, specified in any of the
4305 ways acceptable to the `set` command.
4307 If a +'name'+ refers to an element of an array, then that
4308 element is removed without affecting the rest of the array.
4310 If a +'name'+ consists of an array name with no parenthesized
4311 index, then the entire array is deleted.
4313 The `unset` command returns an empty string as result.
4315 An error occurs if any of the variables doesn't exist, unless '-nocomplain'
4316 is specified. The '--' argument may be specified to stop option processing
4317 in case the variable name may be '-nocomplain'.
4321 +*upcall* 'command ?args ...?'+
4323 May be used from within a proc defined as `local` `proc` in order to call
4324 the previous, hidden version of the same command.
4326 If there is no previous definition of the command, an error is returned.
4330 +*uplevel* '?level? command ?command ...?'+
4332 All of the +'command'+ arguments are concatenated as if they had
4333 been passed to `concat`; the result is then evaluated in the
4334 variable context indicated by +'level'+. `uplevel` returns
4335 the result of that evaluation. If +'level'+ is an integer, then
4336 it gives a distance (up the procedure calling stack) to move before
4337 executing the command. If +'level'+ consists of +\#+ followed by
4338 a number then the number gives an absolute level number. If +'level'+
4339 is omitted then it defaults to +1+. +'level'+ cannot be
4340 defaulted if the first +'command'+ argument starts with a digit or +#+.
4342 For example, suppose that procedure 'a' was invoked
4343 from top-level, and that it called 'b', and that 'b' called 'c'.
4344 Suppose that 'c' invokes the `uplevel` command. If +'level'+
4345 is +1+ or +#2+ or omitted, then the command will be executed
4346 in the variable context of 'b'. If +'level'+ is +2+ or +#1+
4347 then the command will be executed in the variable context of 'a'.
4349 If +'level'+ is '3' or +#0+ then the command will be executed
4350 at top-level (only global variables will be visible).
4351 The `uplevel` command causes the invoking procedure to disappear
4352 from the procedure calling stack while the command is being executed.
4353 In the above example, suppose 'c' invokes the command
4355 uplevel 1 {set x 43; d}
4357 where 'd' is another Tcl procedure. The `set` command will
4358 modify the variable 'x' in 'b's context, and 'd' will execute
4359 at level 3, as if called from 'b'. If it in turn executes
4364 then the `set` command will modify the same variable 'x' in 'b's
4365 context: the procedure 'c' does not appear to be on the call stack
4366 when 'd' is executing. The command `info level` may
4367 be used to obtain the level of the current procedure.
4369 `uplevel` makes it possible to implement new control
4370 constructs as Tcl procedures (for example, `uplevel` could
4371 be used to implement the `while` construct as a Tcl procedure).
4375 +*upvar* '?level? otherVar myVar ?otherVar myVar ...?'+
4377 This command arranges for one or more local variables in the current
4378 procedure to refer to variables in an enclosing procedure call or
4379 to global variables.
4381 +'level'+ may have any of the forms permitted for the `uplevel`
4382 command, and may be omitted if the first letter of the first +'otherVar'+
4383 isn't +#+ or a digit (it defaults to '1').
4385 For each +'otherVar'+ argument, `upvar` makes the variable
4386 by that name in the procedure frame given by +'level'+ (or at
4387 global level, if +'level'+ is +#0+) accessible
4388 in the current procedure by the name given in the corresponding
4391 The variable named by +'otherVar'+ need not exist at the time of the
4392 call; it will be created the first time +'myVar'+ is referenced, just like
4393 an ordinary variable.
4395 `upvar` may only be invoked from within procedures.
4397 `upvar` returns an empty string.
4399 The `upvar` command simplifies the implementation of call-by-name
4400 procedure calling and also makes it easier to build new control constructs
4402 For example, consider the following procedure:
4409 'add2' is invoked with an argument giving the name of a variable,
4410 and it adds two to the value of that variable.
4411 Although 'add2' could have been implemented using `uplevel`
4412 instead of `upvar`, `upvar` makes it simpler for 'add2'
4413 to access the variable in the caller's procedure frame.
4417 +*while* 'test body'+
4419 The +'while'+ command evaluates +'test'+ as an expression
4420 (in the same way that `expr` evaluates its argument).
4421 The value of the expression must be numeric; if it is non-zero
4422 then +'body'+ is executed by passing it to the Tcl interpreter.
4424 Once +'body'+ has been executed then +'test'+ is evaluated
4425 again, and the process repeats until eventually +'test'+
4426 evaluates to a zero numeric value. `continue`
4427 commands may be executed inside +'body'+ to terminate the current
4428 iteration of the loop, and `break`
4429 commands may be executed inside +'body'+ to cause immediate
4430 termination of the `while` command.
4432 The `while` command always returns an empty string.
4437 The following extensions may or may not be available depending upon
4438 what options were selected when Jim Tcl was built.
4441 posix: os.fork, os.wait, os.gethostname, os.getids, os.uptime
4442 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4444 Invokes 'fork(2)' and returns the result.
4446 +*os.wait -nohang* 'pid'+::
4447 Invokes waitpid(2), with WNOHANG if +-nohang+ is specified.
4448 Returns a list of 3 elements.
4450 {0 none 0} if -nohang is specified, and the process is still alive.
4452 {-1 error <error-description>} if the process does not exist or has already been waited for.
4454 {<pid> exit <exit-status>} if the process exited normally.
4456 {<pid> signal <signal-number>} if the process terminated on a signal.
4458 {<pid> other 0} otherwise (core dump, stopped, continued, etc.)
4460 +*os.gethostname*+::
4461 Invokes 'gethostname(3)' and returns the result.
4464 Returns the various user/group ids for the current process.
4467 uid 1000 euid 1000 gid 100 egid 100
4470 Returns the number of seconds since system boot. See description of 'uptime' in 'sysinfo(2)'.
4472 ANSI I/O (aio) and EVENTLOOP API
4473 --------------------------------
4474 Jim provides an alternative object-based API for I/O.
4476 See `open` and `socket` for commands which return an I/O handle.
4480 +$handle *accept* ?addrvar?+::
4481 Server socket only: Accept a connection and return stream.
4482 If +'addrvar'+ is specified, the address of the connected client is stored
4483 in the named variable in the form 'addr:port'. See `socket` for details.
4485 +$handle *buffering none|line|full*+::
4486 Sets the buffering mode of the stream.
4488 +$handle *close* ?r(ead)|w(rite)?+::
4490 The two-argument form is a "half-close" on a socket. See the +shutdown(2)+ man page.
4492 +$handle *copyto* 'tofd ?size?'+::
4493 Copy bytes to the file descriptor +'tofd'+. If +'size'+ is specified, at most
4494 that many bytes will be copied. Otherwise copying continues until the end
4495 of the input file. Returns the number of bytes actually copied.
4498 Returns 1 if stream is at eof
4500 +$handle *filename*+::
4501 Returns the original filename associated with the handle.
4502 Handles returned by `socket` give the socket type instead of a filename.
4507 +$handle *gets* '?var?'+::
4508 Read one line and return it or store it in the var
4510 +$handle *isatty*+::
4511 Returns 1 if the stream is a tty device.
4513 +$handle *ndelay ?0|1?*+::
4514 Set O_NDELAY (if arg). Returns current/new setting.
4515 Note that in general ANSI I/O interacts badly with non-blocking I/O.
4518 +$handle *puts ?-nonewline?* 'str'+::
4519 Write the string, with newline unless -nonewline
4521 +$handle *read ?-nonewline?* '?len?'+::
4522 Read and return bytes from the stream. To eof if no len.
4524 +$handle *recvfrom* 'maxlen ?addrvar?'+::
4525 Receives a message from the handle via recvfrom(2) and returns it.
4526 At most +'maxlen'+ bytes are read.
4527 If +'addrvar'+ is specified, the sending address of the message is stored in
4528 the named variable in the form 'addr:port'. See `socket` for details.
4530 +$handle *seek* 'offset' *?start|current|end?*+::
4531 Seeks in the stream (default 'current')
4533 +$handle *sendto* 'str ?addr:?port'+::
4534 Sends the string, +'str'+, to the given address via the socket using sendto(2).
4535 This is intended for udp/dgram sockets and may give an error or behave in unintended
4536 ways for other handle types.
4537 Returns the number of bytes written.
4540 Flush the stream, then fsync(2) to commit any changes to storage.
4541 Only available on platforms that support fsync(2).
4544 Returns the current seek position
4546 +$handle *ssl* *?-server cert priv?*+::
4547 Initiates a SSL/TLS session and returns a new stream
4549 +$handle *verify*+::
4550 Verifies the certificate of a SSL/TLS stream peer
4552 +*load_ssl_certs* 'dir'+::
4553 Loads SSL/TLS CA certificates for use during verification
4557 +*fconfigure* 'handle' *?-blocking 0|1? ?-buffering noneline|full? ?-translation* 'mode'?+::
4558 For compatibility with Tcl, a limited form of the `fconfigure`
4559 command is supported.
4560 * `fconfigure ... -blocking` maps to `aio ndelay`
4561 * `fconfigure ... -buffering` maps to `aio buffering`
4562 * `fconfigure ... -translation` is accepted but ignored
4565 eventloop: after, vwait, update
4566 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4568 The following commands allow a script to be invoked when the given condition occurs.
4569 If no script is given, returns the current script. If the given script is the empty, the
4572 +$handle *readable* '?readable-script?'+::
4573 Sets or returns the script for when the socket is readable.
4575 +$handle *writable* '?writable-script?'+::
4576 Sets or returns the script for when the socket is writable.
4578 +$handle *onexception* '?exception-script?'+::
4579 Sets or returns the script for when oob data received.
4581 For compatibility with 'Tcl', these may be prefixed with `fileevent`. e.g.
4584 +fileevent $handle *readable* '\...'+
4586 Time-based execution is also available via the eventloop API.
4589 Sleeps for the given number of milliseconds. No events are
4590 processed during this time.
4592 +*after* 'ms'|*idle* 'script ?script \...?'+::
4593 The scripts are concatenated and executed after the given
4594 number of milliseconds have elapsed. If 'idle' is specified,
4595 the script will run the next time the event loop is processed
4596 with `vwait` or `update`. The script is only run once and
4597 then removed. Returns an event id.
4599 +*after cancel* 'id|command'+::
4600 Cancels an `after` event with the given event id or matching
4601 command (script). Returns the number of milliseconds
4602 remaining until the event would have fired. Returns the
4603 empty string if no matching event is found.
4605 +*after info* '?id?'+::
4606 If +'id'+ is not given, returns a list of current `after`
4607 events. If +'id'+ is given, returns a list containing the
4608 associated script and either 'timer' or 'idle' to indicated
4609 the type of the event. An error occurs if +'id'+ does not
4612 +*vwait* 'variable'+::
4613 A call to `vwait` is enters the eventloop. `vwait` processes
4614 events until the named (global) variable changes or all
4615 event handlers are removed. The variable need not exist
4616 beforehand. If there are no event handlers defined, `vwait`
4617 returns immediately.
4619 +*update ?idletasks?*+::
4620 A call to `update` enters the eventloop to process expired events, but
4621 no new events. If 'idletasks' is specified, only expired time events are handled,
4623 Returns once handlers have been run for all expired events.
4625 Scripts are executed at the global scope. If an error occurs during a handler script,
4626 an attempt is made to call (the user-defined command) `bgerror` with the details of the error.
4627 If the `bgerror` command does not exist, the error message details are printed to stderr instead.
4629 If a file event handler script generates an error, the handler is automatically removed
4630 to prevent infinite errors. (A time event handler is always removed after execution).
4633 Called when an event handler script generates an error. Note that the normal command resolution
4634 rules are used for bgerror. First the name is resolved in the current namespace, then in the
4639 Various socket types may be created.
4641 +*socket unix* 'path'+::
4642 A unix domain socket client.
4644 +*socket unix.server* 'path'+::
4645 A unix domain socket server.
4647 +*socket ?-ipv6? stream* 'addr:port'+::
4648 A TCP socket client. (See the forms for +'addr'+ below)
4650 +*socket ?-ipv6? stream.server* '?addr:?port'+::
4651 A TCP socket server (+'addr'+ defaults to +0.0.0.0+ for IPv4 or +[::]+ for IPv6).
4653 +*socket ?-ipv6? dgram* ?'addr:port'?+::
4654 A UDP socket client. If the address is not specified,
4655 the client socket will be unbound and 'sendto' must be used
4656 to indicated the destination.
4658 +*socket ?-ipv6? dgram.server* 'addr:port'+::
4659 A UDP socket server.
4662 A pipe. Note that unlike all other socket types, this command returns
4663 a list of two channels: {read write}
4666 A socketpair (see socketpair(2)). Like `socket pipe`, this command returns
4667 a list of two channels: {s1 s2}. These channels are both readable and writable.
4669 This command creates a socket connected (client) or bound (server) to the given
4672 The returned value is channel and may generally be used with the various file I/O
4673 commands (gets, puts, read, etc.), either as object-based syntax or Tcl-compatible syntax.
4675 set f [socket stream www.google.com:80]
4677 $f puts -nonewline "GET / HTTP/1.0\r\n\r\n"
4682 Server sockets, however support only 'accept', which is most useful in conjunction with
4685 set f [socket stream.server 80]
4687 set client [$f accept]
4690 $client puts -nonewline "HTTP/1.1 404 Not found\r\n"
4695 The address, +'addr'+, can be given in one of the following forms:
4697 1. For IPv4 socket types, an IPv4 address such as 192.168.1.1
4698 2. For IPv6 socket types, an IPv6 address such as [fe80::1234] or [::]
4701 Note that on many systems, listening on an IPv6 address such as [::] will
4702 also accept requests via IPv4.
4704 Where a hostname is specified, the +'first'+ returned address is used
4705 which matches the socket type is used.
4707 The special type 'pipe' isn't really a socket.
4709 lassign [socket pipe] r w
4711 # Must close $w after exec
4719 +*syslog* '?options? ?priority? message'+
4721 This command sends message to system syslog facility with given
4722 priority. Valid priorities are:
4724 emerg, alert, crit, err, error, warning, notice, info, debug
4726 If a message is specified, but no priority is specified, then a
4727 priority of info is used.
4729 By default, facility user is used and the value of global tcl variable
4730 argv0 is used as ident string. However, any of the following options
4731 may be specified before priority to control these parameters:
4733 +*-facility* 'value'+::
4734 Use specified facility instead of user. The following
4735 values for facility are recognized:
4737 authpriv, cron, daemon, kernel, lpr, mail, news, syslog, user,
4740 +*-ident* 'string'+::
4741 Use given string instead of argv0 variable for ident string.
4743 +*-options* 'integer'+::
4744 Set syslog options such as +LOG_CONS+, +LOG_NDELAY+. You should
4745 use numeric values of those from your system syslog.h file,
4746 because I haven't got time to implement yet another hash
4751 The optional 'pack' extension provides commands to encode and decode binary strings.
4753 +*pack* 'varName value' *-intle|-intbe|-floatle|-floatbe|-str* 'bitwidth ?bitoffset?'+::
4754 Packs the binary representation of +'value'+ into the variable
4755 +'varName'+. The value is packed according to the given type
4756 (integer/floating point/string, big-endian/little-endian), width and bit offset.
4757 The variable is created if necessary (like `append`).
4758 The variable is expanded if necessary.
4760 +*unpack* 'binvalue' *-intbe|-intle|-uintbe|-uintle|-floatbe|-floatle|-str* 'bitpos bitwidth'+::
4761 Unpacks bits from +'binvalue'+ at bit position +'bitpos'+ and with +'bitwidth'+.
4762 Interprets the value according to the type (integer/floating point/string, big-endian/little-endian
4763 and signed/unsigned) and returns it. For integer types, +'bitwidth'+
4764 may be up to the size of a Jim Tcl integer (typically 64 bits). For floating point types,
4765 +'bitwidth'+ may be 32 bits (for single precision numbers) or 64 bits (for double precision).
4766 For the string type, both the width and the offset must be on a byte boundary (multiple of 8). Attempting to
4767 access outside the length of the value will return 0 for integer types, 0.0 for floating point types
4768 or the empty string for the string type.
4772 The optional, pure-Tcl 'binary' extension provides the Tcl-compatible `binary scan` and `binary format`
4773 commands based on the low-level `pack` and `unpack` commands.
4775 See the Tcl documentation at: http://www.tcl.tk/man/tcl8.5/TclCmd/binary.htm
4777 Note that 'binary format' with f/r/R specifiers (single-precision float) uses the value of Infinity
4778 in case of overflow.
4782 The optional, pure-Tcl 'oo' extension provides object-oriented (OO) support for Jim Tcl.
4784 See the online documentation (http://jim.tcl.tk/index.html/doc/www/www/documentation/oo/) for more details.
4786 +*class* 'classname ?baseclasses? classvars'+::
4787 Create a new class, +'classname'+, with the given dictionary
4788 (+'classvars'+) as class variables. These are the initial variables
4789 which all newly created objects of this class are initialised with.
4790 If a list of baseclasses is given, methods and instance variables
4793 +*super* 'method ?args \...?'+::
4794 From within a method, invokes the given method on the base class.
4795 Note that this will only call the last baseclass given.
4799 The optional, pure-Tcl 'tree' extension implements an OO, general purpose tree structure
4800 similar to that provided by tcllib ::struct::tree (http://core.tcl.tk/tcllib/doc/trunk/embedded/www/tcllib/files/modules/struct/struct_tree.html)
4802 A tree is a collection of nodes, where each node (except the root node) has a single parent
4803 and zero or more child nodes (ordered), as well as zero or more attribute/value pairs.
4806 Creates and returns a new tree object with a single node named "root".
4807 All operations on the tree are invoked through this object.
4810 Destroy the tree and all it's nodes. (Note that the tree will also
4811 be automatically garbage collected once it goes out of scope).
4813 +$tree *set* 'nodename key value'+::
4814 Set the value for the given attribute key.
4816 +$tree *lappend* 'nodename key value \...'+::
4817 Append to the (list) value(s) for the given attribute key, or set if not yet set.
4819 +$tree *keyexists* 'nodename key'+::
4820 Returns 1 if the given attribute key exists.
4822 +$tree *get* 'nodename key'+::
4823 Returns the value associated with the given attribute key.
4825 +$tree *getall* 'nodename'+::
4826 Returns the entire attribute dictionary associated with the given key.
4828 +$tree *depth* 'nodename'+::
4829 Returns the depth of the given node. The depth of "root" is 0.
4831 +$tree *parent* 'nodename'+::
4832 Returns the node name of the parent node, or "" for the root node.
4834 +$tree *numchildren* 'nodename'+::
4835 Returns the number of child nodes.
4837 +$tree *children* 'nodename'+::
4838 Returns a list of the child nodes.
4840 +$tree *next* 'nodename'+::
4841 Returns the next sibling node, or "" if none.
4843 +$tree *insert* 'nodename ?index?'+::
4844 Add a new child node to the given node. The index is a list index
4845 such as +3+ or +end-2+. The default index is +end+.
4846 Returns the name of the newly added node.
4848 +$tree *walk* 'nodename' *dfs|bfs* {'actionvar nodevar'} 'script'+::
4849 Walks the tree starting from the given node, either breadth first (+bfs+)
4850 depth first (+dfs+).
4851 The value +"enter"+ or +"exit"+ is stored in variable +'actionvar'+.
4852 The name of each node is stored in +'nodevar'+.
4853 The script is evaluated twice for each node, on entry and exit.
4856 Dumps the tree contents to stdout
4860 The optional tclprefix extension provides the Tcl8.6-compatible 'tcl::prefix' command
4861 (http://www.tcl.tk/man/tcl8.6/TclCmd/prefix.htm) for matching strings against a table
4862 of possible values (typically commands or options).
4864 +*tcl::prefix all* 'table string'+::
4865 Returns a list of all elements in +'table'+ that begin with the prefix +'string'+.
4867 +*tcl::prefix longest* 'table string'+::
4868 Returns the longest common prefix of all elements in +'table'+ that begin with the prefix +'string'+.
4870 +*tcl::prefix match* '?options? table string'+::
4871 If +'string'+ equals one element in +'table'+ or is a prefix to
4872 exactly one element, the matched element is returned. If not, the
4873 result depends on the +-error+ option.
4875 * +*-exact*+ Accept only exact matches.
4876 * +*-message* 'string'+ Use +'string'+ in the error message at a mismatch. Default is "option".
4877 * +*-error* 'options'+ The options are used when no match is found. If +'options'+ is
4878 empty, no error is generated and an empty string is returned.
4879 Otherwise the options are used as return options when
4880 generating the error message. The default corresponds to
4885 The optional history extension provides script access to the command line editing
4886 and history support available in 'jimsh'. See 'examples/jtclsh.tcl' for an example.
4887 Note: if line editing support is not available, `history getline` acts like `gets` and
4888 the remaining subcommands do nothing.
4890 +*history load* 'filename'+::
4891 Load history from a (text) file. If the file does not exist or is not readable,
4894 +*history getline* 'prompt ?varname?'+::
4895 Displays the given prompt and allows a line to be entered. Similarly to `gets`,
4896 if +'varname'+ is given, it receives the line and the length of the line is returned,
4897 or -1 on EOF. If +'varname'+ is not given, the line is returned directly.
4899 +*history add* 'line'+::
4900 Adds the given line to the history buffer.
4902 +*history save* 'filename'+::
4903 Saves the current history buffer to the given file.
4906 Displays the current history buffer to standard output.
4910 Provides namespace-related functions. See also: http://www.tcl.tk/man/tcl8.6/TclCmd/namespace.htm
4912 +*namespace code* 'script'+::
4913 Captures the current namespace context for later execution of
4914 the script +'script'+. It returns a new script in which script has
4915 been wrapped in a +*namespace inscope*+ command.
4917 +*namespace current*+::
4918 Returns the fully-qualified name for the current namespace.
4920 +*namespace delete* '?namespace ...?'+::
4921 Deletes all commands and variables with the given namespace prefixes.
4923 +*namespace eval* 'namespace arg ?arg...?'+::
4924 Activates a namespace called +'namespace'+ and evaluates some code in that context.
4926 +*namespace origin* 'command'+::
4927 Returns the fully-qualified name of the original command to which the imported command +'command'+ refers.
4929 +*namespace parent* ?namespace?+::
4930 Returns the fully-qualified name of the parent namespace for namespace +'namespace'+, if given, otherwise
4931 for the current namespace.
4933 +*namespace qualifiers* 'string'+::
4934 Returns any leading namespace qualifiers for +'string'+
4936 +*namespace tail* 'string'+::
4937 Returns the simple name at the end of a qualified string.
4939 +*namespace upvar* 'namespace ?arg...?'+::
4940 This command arranges for zero or more local variables in the current procedure to refer to variables in +'namespace'+
4942 +*namespace which* '?-command|-variable? name'+::
4943 Looks up +'name'+ as either a command (the default) or variable and returns its fully-qualified name.
4945 [[BuiltinVariables]]
4949 The following global variables are created automatically
4953 This variable is set by Jim as an array
4954 whose elements are the environment variables for the process.
4955 Reading an element will return the value of the corresponding
4956 environment variable.
4957 This array is initialised at startup from the `env` command.
4958 It may be modified and will affect the environment passed to
4959 commands invoked with `exec`.
4962 This variable is set by Jim as an array containing information
4963 about the platform on which Jim was built. Currently this includes
4964 'os' and 'platform'.
4967 This variable contains a list of paths to search for packages.
4968 It defaults to a location based on where jim is installed
4969 (e.g. +/usr/local/lib/jim+), but may be changed by +jimsh+
4970 or the embedding application. Note that +jimsh+ will consider
4971 the environment variable +$JIMLIB+ to be a list of colon-separated
4972 list of paths to add to +*auto_path*+.
4975 This variable holds the value of the -errorcode return
4976 option set by the most recent error that occurred in this
4977 interpreter. This list value represents additional information
4978 about the error in a form that is easy to process with
4979 programs. The first element of the list identifies a general
4980 class of errors, and determines the format of the rest of
4981 the list. The following formats for -errorcode return options
4982 are used by the Tcl core; individual applications may define
4983 additional formats. Currently only `exec` sets this variable.
4984 Otherwise it will be +NONE+.
4986 The following global variables are set by jimsh.
4988 +*tcl_interactive*+::
4989 This variable is set to 1 if jimsh is started in interactive mode
4993 This variable is set by Jim as an array containing information
4994 about the platform upon which Jim was built. The following is an
4995 example of the contents of this array.
4997 tcl_platform(byteOrder) = littleEndian
4998 tcl_platform(engine) = Jim
4999 tcl_platform(os) = Darwin
5000 tcl_platform(platform) = unix
5001 tcl_platform(pointerSize) = 8
5002 tcl_platform(threaded) = 0
5003 tcl_platform(wordSize) = 8
5004 tcl_platform(pathSeparator) = :
5007 If jimsh is invoked to run a script, this variable contains the name
5011 If jimsh is invoked to run a script, this variable contains a list
5012 of any arguments supplied to the script.
5015 If jimsh is invoked to run a script, this variable contains the number
5016 of arguments supplied to the script.
5019 The value of argv[0] when jimsh was invoked.
5021 CHANGES IN PREVIOUS RELEASES
5022 ----------------------------
5026 1. +platform_tcl()+ settings are now automatically determined
5027 2. Add aio `$handle filename`
5028 3. Add `info channels`
5029 4. The 'bio' extension is gone. Now `aio` supports 'copyto'.
5030 5. Add `exists` command
5031 6. Add the pure-Tcl 'oo' extension
5032 7. The `exec` command now only uses vfork(), not fork()
5033 8. Unit test framework is less verbose and more Tcl-compatible
5034 9. Optional UTF-8 support
5035 10. Optional built-in regexp engine for better Tcl compatibility and UTF-8 support
5036 11. Command line editing in interactive mode, e.g. 'jimsh'
5040 1. `source` now checks that a script is complete (.i.e. not missing a brace)
5041 2. 'info complete' now uses the real parser and so is 100% accurate
5042 3. Better access to live stack frames with 'info frame', `stacktrace` and `stackdump`
5043 4. `tailcall` no longer loses stack trace information
5044 5. Add `alias` and `curry`
5045 6. `lambda`, `alias` and `curry` are implemented via `tailcall` for efficiency
5046 7. `local` allows procedures to be deleted automatically at the end of the current procedure
5047 8. udp sockets are now supported for both clients and servers.
5048 9. vfork-based exec is now working correctly
5049 10. Add 'file tempfile'
5050 11. Add 'socket pipe'
5051 12. Enhance 'try ... on ... finally' to be more Tcl 8.6 compatible
5052 13. It is now possible to `return` from within `try`
5053 14. IPv6 support is now included
5055 16. Event handlers works better if an error occurs. eof handler has been removed.
5056 17. `exec` now sets $::errorCode, and catch sets opts(-errorcode) for exit status
5057 18. Command pipelines via open "|..." are now supported
5058 19. `pid` can now return pids of a command pipeline
5059 20. Add 'info references'
5060 21. Add support for 'after +'ms'+', 'after idle', 'after info', `update`
5061 22. `exec` now sets environment based on $::env
5063 24. Add support for 'lsort -index'
5067 1. Add support to `exec` for '>&', '>>&', '|&', '2>@1'
5068 2. Fix `exec` error messages when special token (e.g. '>') is the last token
5069 3. Fix `subst` handling of backslash escapes.
5070 4. Allow abbreviated options for `subst`
5071 5. Add support for `return`, `break`, `continue` in subst
5072 6. Many `expr` bug fixes
5073 7. Add support for functions in `expr` (e.g. int(), abs()), and also 'in', 'ni' list operations
5074 8. The variable name argument to `regsub` is now optional
5075 9. Add support for 'unset -nocomplain'
5076 10. Add support for list commands: `lassign`, `lrepeat`
5077 11. Fully-functional `lsearch` is now implemented
5078 12. Add 'info nameofexecutable' and 'info returncodes'
5079 13. Allow `catch` to determine what return codes are caught
5080 14. Allow `incr` to increment an unset variable by first setting to 0
5081 15. Allow 'args' and optional arguments to the left or required arguments in `proc`
5083 17. Add 'try ... finally' command
5089 Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
5090 Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
5091 Copyright 2005 patthoyts - Pat Thoyts <patthoyts@users.sf.net>
5092 Copyright 2008 oharboe - Oyvind Harboe - oyvind.harboe@zylin.com
5093 Copyright 2008 Andrew Lunn <andrew@lunn.ch>
5094 Copyright 2008 Duane Ellis <openocd@duaneellis.com>
5095 Copyright 2008 Uwe Klein <uklein@klein-messgeraete.de>
5096 Copyright 2009 Steve Bennett <steveb@workware.net.au>
5099 Redistribution and use in source and binary forms, with or without
5100 modification, are permitted provided that the following conditions
5102 1. Redistributions of source code must retain the above copyright
5103 notice, this list of conditions and the following disclaimer.
5104 2. Redistributions in binary form must reproduce the above
5105 copyright notice, this list of conditions and the following
5106 disclaimer in the documentation and/or other materials
5107 provided with the distribution.
5109 THIS SOFTWARE IS PROVIDED BY THE JIM TCL PROJECT ``AS IS'' AND ANY
5110 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
5111 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
5112 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
5113 JIM TCL PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
5114 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
5115 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
5116 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
5117 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
5118 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
5119 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
5120 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
5122 The views and conclusions contained in the software and documentation
5123 are those of the authors and should not be interpreted as representing
5124 official policies, either expressed or implied, of the Jim Tcl Project.