6 Jim Tcl v0.72 - overview of the Jim tool command language facilities
16 jimsh -e '<immediate-script>'
21 * <<CommandIndex,Command Reference>>
22 * <<OperatorPrecedence,Operator Precedence>>
23 * <<BuiltinVariables, Builtin Variables>>
24 * <<BackslashSequences, Backslash Sequences>>
28 Jim is a reimplementation of Tcl, combining some features from
29 earlier, smaller versions of Tcl (6.x) as well as more modern
30 features from later versions of Tcl (7.x, 8.x). It also has some some
31 entirely new features not available in any version of Tcl.
33 This version is about double the size of "tinytcl" (6.8), depending upon
34 the features selected, but is significantly faster and has many new features.
36 Note that most of this man page is the original 6.8 Tcl man page, with
37 changes made for differences with Jim.
39 The major differences with Tcl 8.5/8.6 are:
41 1. Object-based I/O (aio), but with a Tcl-compatibility layer
42 2. I/O: Support for sockets and pipes including udp, unix domain sockets and IPv6
44 4. Support for references (`ref`/`getref`/`setref`) and garbage collection
45 5. Builtin dictionary type (`dict`) with some limitations compared to Tcl 8.6
46 6. `env` command to access environment variables
47 7. `os.fork`, `os.wait`, `os.uptime`, `rand`
48 8. Much better error reporting. `info stacktrace` as a replacement for '$errorInfo', '$errorCode'
49 9. Support for "static" variables in procedures
50 10. Namespaces, threads and coroutines are not support
51 11. Command and variable traces are not supported
52 12. Direct command line editing rather than the `history` command
53 13. Expression shorthand syntax: +$(...)+
58 Changes between 0.71 and 0.72
59 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
60 1. procs now allow 'args' and optional parameters in any position
61 2. Add Tcl-compatible expr functions, `rand()`, `srand()` and `pow()`
62 3. Add support for the '-force' option to `file delete`
63 4. Better diagnostics when `source` fails to load a script with a missing quote or bracket
64 5. New +tcl_platform(pathSeparator)+
65 6. Add support settings the modification time with `file mtime`
66 7. `exec` is now fully supported on win32 (mingw32)
67 8. `file join`, `pwd`, `glob` etc. now work for mingw32
68 9. Line editing is now supported for the win32 console (mingw32)
69 10. Add `aio listen` command
71 Changes between 0.70 and 0.71
72 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
73 1. Allow 'args' to be renamed in procs
74 2. Add +$(...)+ shorthand syntax for expressions
75 3. Add automatic reference variables in procs with +&var+ syntax
76 4. Support +jimsh --version+
77 5. Additional variables in +tcl_platform()+
78 6. `local` procs now push existing commands and `upcall` can call them
79 7. Add `loop` command (TclX compatible)
80 8. Add `aio buffering` command
81 9. `info complete` can now return the missing character
82 10. `binary format` and `binary scan` are now (optionally) supported
83 11. Add `string byterange`
84 12. Built-in regexp now support non-greedy repetition (*?, +?, ??)
86 Changes between 0.63 and 0.70
87 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
88 1. +platform_tcl()+ settings are now automatically determined
89 2. Add aio `$handle filename`
90 3. Add `info channels`
91 4. The 'bio' extension is gone. Now `aio` supports 'copyto'.
92 5. Add `exists` command
93 6. Add the pure-Tcl 'oo' extension
94 7. The `exec` command now only uses vfork(), not fork()
95 8. Unit test framework is less verbose and more Tcl-compatible
96 9. Optional UTF-8 support
97 10. Optional built-in regexp engine for better Tcl compatibility and UTF-8 support
98 11. Command line editing in interactive mode, e.g. 'jimsh'
102 Tcl stands for 'tool command language' and is pronounced 'tickle.'
103 It is actually two things: a language and a library.
105 First, Tcl is a simple textual language, intended primarily for
106 issuing commands to interactive programs such as text editors,
107 debuggers, illustrators, and shells. It has a simple syntax and is also
108 programmable, so Tcl users can write command procedures to provide more
109 powerful commands than those in the built-in set.
111 Second, Tcl is a library package that can be embedded in application
112 programs. The Tcl library consists of a parser for the Tcl language,
113 routines to implement the Tcl built-in commands, and procedures that
114 allow each application to extend Tcl with additional commands specific
115 to that application. The application program generates Tcl commands and
116 passes them to the Tcl parser for execution. Commands may be generated
117 by reading characters from an input source, or by associating command
118 strings with elements of the application's user interface, such as menu
119 entries, buttons, or keystrokes.
121 When the Tcl library receives commands it parses them into component
122 fields and executes built-in commands directly. For commands implemented
123 by the application, Tcl calls back to the application to execute the
124 commands. In many cases commands will invoke recursive invocations of the
125 Tcl interpreter by passing in additional strings to execute (procedures,
126 looping commands, and conditional commands all work in this way).
128 An application program gains three advantages by using Tcl for its command
129 language. First, Tcl provides a standard syntax: once users know Tcl,
130 they will be able to issue commands easily to any Tcl-based application.
131 Second, Tcl provides programmability. All a Tcl application needs
132 to do is to implement a few application-specific low-level commands.
133 Tcl provides many utility commands plus a general programming interface
134 for building up complex command procedures. By using Tcl, applications
135 need not re-implement these features.
137 Third, Tcl can be used as a common language for communicating between
138 applications. Inter-application communication is not built into the
139 Tcl core described here, but various add-on libraries, such as the Tk
140 toolkit, allow applications to issue commands to each other. This makes
141 it possible for applications to work together in much more powerful ways
142 than was previously possible.
144 Fourth, Jim Tcl includes a command processor, +jimsh+, which can be
145 used to run standalone Tcl scripts, or to run Tcl commands interactively.
147 This manual page focuses primarily on the Tcl language. It describes
148 the language syntax and the built-in commands that will be available
149 in any application based on Tcl. The individual library procedures are
150 described in more detail in separate manual pages, one per procedure.
152 JIMSH COMMAND INTERPRETER
153 -------------------------
154 A simple, but powerful command processor, +jimsh+, is part of Jim Tcl.
155 It may be invoked in interactive mode as:
159 or to process the Tcl script in a file with:
163 It may also be invoked to execute an immediate script with:
169 Interactive mode reads Tcl commands from standard input, evaluates
170 those commands and prints the results.
173 Welcome to Jim version 0.71, Copyright (c) 2005-8 Salvatore Sanfilippo
176 . lsort [info commands p*]
177 package parray pid popen proc puts pwd
178 . foreach i {a b c} {
185 invalid command name "bad"
189 If +jimsh+ is configured with line editing (it is by default) and a VT-100-compatible
190 terminal is detected, Emacs-style line editing commands are available, including:
191 arrow keys, +\^W+ to erase a word, +\^U+ to erase the line, +^R+ for reverse incremental search
192 in history. Additionally, the +h+ command may be used to display the command history.
194 Command line history is automatically saved and loaded from +~/.jim_history+
196 In interactive mode, +jimsh+ automatically runs the script +~/.jimrc+ at startup
201 The central data structure in Tcl is an interpreter (C type 'Jim_Interp').
202 An interpreter consists of a set of command bindings, a set of variable
203 values, and a few other miscellaneous pieces of state. Each Tcl command
204 is interpreted in the context of a particular interpreter.
206 Some Tcl-based applications will maintain multiple interpreters
207 simultaneously, each associated with a different widget or portion of
208 the application. Interpreters are relatively lightweight structures.
209 They can be created and deleted quickly, so application programmers should
210 feel free to use multiple interpreters if that simplifies the application.
214 Tcl supports only one type of data: strings. All commands, all arguments
215 to commands, all command results, and all variable values are strings.
217 Where commands require numeric arguments or return numeric results,
218 the arguments and results are passed as strings. Many commands expect
219 their string arguments to have certain formats, but this interpretation
220 is up to the individual commands. For example, arguments often contain
221 Tcl command strings, which may get executed as part of the commands.
222 The easiest way to understand the Tcl interpreter is to remember that
223 everything is just an operation on a string. In many cases Tcl constructs
224 will look similar to more structured constructs from other languages.
225 However, the Tcl constructs are not structured at all; they are just
226 strings of characters, and this gives them a different behaviour than
227 the structures they may look like.
229 Although the exact interpretation of a Tcl string depends on who is doing
230 the interpretation, there are three common forms that strings take:
231 commands, expressions, and lists. The major sections below discuss
232 these three forms in more detail.
236 The Tcl language has syntactic similarities to both the Unix shells
237 and Lisp. However, the interpretation of commands is different
238 in Tcl than in either of those other two systems.
239 A Tcl command string consists of one or more commands separated
240 by newline characters or semi-colons.
241 Each command consists of a collection of fields separated by
242 white space (spaces or tabs).
243 The first field must be the name of a command, and the
244 additional fields, if any, are arguments that will be passed to
245 that command. For example, the command:
249 has three fields: the first, `set`, is the name of a Tcl command, and
250 the last two, 'a' and '22', will be passed as arguments to
251 the `set` command. The command name may refer either to a built-in
252 Tcl command, an application-specific command bound in with the library
253 procedure 'Jim_CreateCommand', or a command procedure defined with the
254 `proc` built-in command.
256 Arguments are passed literally as text strings. Individual commands may
257 interpret those strings in any fashion they wish. The `set` command,
258 for example, will treat its first argument as the name of a variable
259 and its second argument as a string value to assign to that variable.
260 For other commands arguments may be interpreted as integers, lists,
261 file names, or Tcl commands.
263 Command names should normally be typed completely (e.g. no abbreviations).
264 However, if the Tcl interpreter cannot locate a command it invokes a
265 special command named `unknown` which attempts to find or create the
268 For example, at many sites `unknown` will search through library
269 directories for the desired command and create it as a Tcl procedure if
270 it is found. The `unknown` command often provides automatic completion
271 of abbreviated commands, but usually only for commands that were typed
274 It's probably a bad idea to use abbreviations in command scripts and
275 other forms that will be re-used over time: changes to the command set
276 may cause abbreviations to become ambiguous, resulting in scripts that
281 If the first non-blank character in a command is +\#+, then everything
282 from the +#+ up through the next newline character is treated as
283 a comment and ignored. When comments are embedded inside nested
284 commands (e.g. fields enclosed in braces) they must have properly-matched
285 braces (this is necessary because when Tcl parses the top-level command
286 it doesn't yet know that the nested field will be used as a command so
287 it cannot process the nested comment character as a comment).
289 GROUPING ARGUMENTS WITH DOUBLE-QUOTES
290 -------------------------------------
291 Normally each argument field ends at the next white space, but
292 double-quotes may be used to create arguments with embedded space.
294 If an argument field begins with a double-quote, then the argument isn't
295 terminated by white space (including newlines) or a semi-colon (see below
296 for information on semi-colons); instead it ends at the next double-quote
297 character. The double-quotes are not included in the resulting argument.
298 For example, the command
300 set a "This is a single argument"
302 will pass two arguments to `set`: 'a' and 'This is a single argument'.
304 Within double-quotes, command substitutions, variable substitutions,
305 and backslash substitutions still occur, as described below. If the
306 first character of a command field is not a quote, then quotes receive
307 no special interpretation in the parsing of that field.
309 GROUPING ARGUMENTS WITH BRACES
310 ------------------------------
311 Curly braces may also be used for grouping arguments. They are similar
312 to quotes except for two differences. First, they nest; this makes them
313 easier to use for complicated arguments like nested Tcl command strings.
314 Second, the substitutions described below for commands, variables, and
315 backslashes do *not* occur in arguments enclosed in braces, so braces
316 can be used to prevent substitutions where they are undesirable.
318 If an argument field begins with a left brace, then the argument ends
319 at the matching right brace. Tcl will strip off the outermost layer
320 of braces and pass the information between the braces to the command
321 without any further modification. For example, in the command
323 set a {xyz a {b c d}}
325 the `set` command will receive two arguments: 'a'
328 When braces or quotes are in effect, the matching brace or quote need
329 not be on the same line as the starting quote or brace; in this case
330 the newline will be included in the argument field along with any other
331 characters up to the matching brace or quote. For example, the `eval`
332 command takes one argument, which is a command string; `eval` invokes
333 the Tcl interpreter to execute the command string. The command
340 will assign the value '22' to 'a' and '33' to 'b'.
342 If the first character of a command field is not a left
343 brace, then neither left nor right
344 braces in the field will be treated specially (except as part of
345 variable substitution; see below).
347 COMMAND SUBSTITUTION WITH BRACKETS
348 ----------------------------------
349 If an open bracket occurs in a field of a command, then command
350 substitution occurs (except for fields enclosed in braces). All of the
351 text up to the matching close bracket is treated as a Tcl command and
352 executed immediately. Then the result of that command is substituted
353 for the bracketed text. For example, consider the command
357 When the `set` command has only a single argument, it is the name of a
358 variable and `set` returns the contents of that variable. In this case,
359 if variable 'b' has the value 'foo', then the command above is equivalent
364 Brackets can be used in more complex ways. For example, if the variable
365 'b' has the value 'foo' and the variable 'c' has the value 'gorp',
368 set a xyz[set b].[set c]
370 is equivalent to the command
375 A bracketed command may contain multiple commands separated by newlines
376 or semi-colons in the usual fashion. In this case the value of the last
377 command is used for substitution. For example, the command
382 is equivalent to the command
387 If a field is enclosed in braces then the brackets and the characters
388 between them are not interpreted specially; they are passed through to
389 the argument verbatim.
391 VARIABLE SUBSTITUTION WITH $
392 ----------------------------
393 The dollar sign (+$+) may be used as a special shorthand form for
394 substituting variable values. If +$+ appears in an argument that isn't
395 enclosed in braces then variable substitution will occur. The characters
396 after the +$+, up to the first character that isn't a number, letter,
397 or underscore, are taken as a variable name and the string value of that
398 variable is substituted for the name.
400 For example, if variable 'foo' has the value 'test', then the command
404 is equivalent to the command
408 There are two special forms for variable substitution. If the next
409 character after the name of the variable is an open parenthesis, then
410 the variable is assumed to be an array name, and all of the characters
411 between the open parenthesis and the next close parenthesis are taken as
412 an index into the array. Command substitutions and variable substitutions
413 are performed on the information between the parentheses before it is
416 For example, if the variable 'x' is an array with one element named
417 'first' and value '87' and another element named '14' and value 'more',
420 set a xyz$x(first)zyx
422 is equivalent to the command
426 If the variable 'index' has the value '14', then the command
428 set a xyz$x($index)zyx
430 is equivalent to the command
434 For more information on arrays, see VARIABLES AND ARRAYS below.
436 The second special form for variables occurs when the dollar sign is
437 followed by an open curly brace. In this case the variable name consists
438 of all the characters up to the next curly brace.
440 Array references are not possible in this form: the name between braces
441 is assumed to refer to a scalar variable. For example, if variable
442 'foo' has the value 'test', then the command
446 is equivalent to the command
451 Variable substitution does not occur in arguments that are enclosed in
452 braces: the dollar sign and variable name are passed through to the
455 The dollar sign abbreviation is simply a shorthand form. +$a+ is
456 completely equivalent to +[set a]+; it is provided as a convenience
459 SEPARATING COMMANDS WITH SEMI-COLONS
460 ------------------------------------
461 Normally, each command occupies one line (the command is terminated by a
462 newline character). However, semi-colon (+;+) is treated as a command
463 separator character; multiple commands may be placed on one line by
464 separating them with a semi-colon. Semi-colons are not treated as
465 command separators if they appear within curly braces or double-quotes.
467 BACKSLASH SUBSTITUTION
468 ----------------------
469 Backslashes may be used to insert non-printing characters into command
470 fields and also to insert special characters like braces and brackets
471 into fields without them being interpreted specially as described above.
473 The backslash sequences understood by the Tcl interpreter are
474 listed below. In each case, the backslash
475 sequence is replaced by the given character:
476 [[BackslashSequences]]
487 Carriage-return (0xd).
510 +{backslash}<space>+::
511 Space ( ): doesn't terminate argument.
514 Semi-colon: doesn't terminate command.
519 +{backslash}<newline>+::
520 Nothing: this joins two lines together
521 into a single line. This backslash feature is unique in that
522 it will be applied even when the sequence occurs within braces.
524 +{backslash}{backslash}+::
525 Backslash ('{backslash}').
528 The digits +'ddd'+ (one, two, or three of them) give the octal value of
529 the character. Note that Jim supports null characters in strings.
531 +{backslash}'unnnn'+::
532 The hex digits +'nnnn'+ (between one and four of them) give a unicode codepoint.
533 The UTF-8 encoding of the codepoint is inserted.
535 For example, in the command
539 the second argument to `set` will be +{x[ yza+.
541 If a backslash is followed by something other than one of the options
542 described above, then the backslash is transmitted to the argument
543 field without any special processing, and the Tcl scanner continues
544 normal processing with the next character. For example, in the
549 The first argument to `set` will be +{backslash}*a+ and the second
550 argument will be +{backslash}{foo+.
552 If an argument is enclosed in braces, then backslash sequences inside
553 the argument are parsed but no substitution occurs (except for
554 backslash-newline): the backslash
555 sequence is passed through to the argument as is, without making
556 any special interpretation of the characters in the backslash sequence.
557 In particular, backslashed braces are not counted in locating the
558 matching right brace that terminates the argument.
564 the second argument to `set` will be +{backslash}{abc+.
566 This backslash mechanism is not sufficient to generate absolutely
567 any argument structure; it only covers the
568 most common cases. To produce particularly complicated arguments
569 it is probably easiest to use the `format` command along with
570 command substitution.
572 STRING AND LIST INDEX SPECIFICATIONS
573 ------------------------------------
575 Many string and list commands take one or more 'index' parameters which
576 specify a position in the string relative to the start or end of the string/list.
578 The index may be one of the following forms:
581 A simple integer, where '0' refers to the first element of the string
584 +integer+integer+ or::
586 The sum or difference of the two integers. e.g. +2+3+ refers to the 5th element.
587 This is useful when used with (e.g.) +$i+1+ rather than the more verbose
591 The last element of the string or list.
594 The 'nth-from-last' element of the string or list.
598 1. A command is just a string.
599 2. Within a string commands are separated by newlines or semi-colons
600 (unless the newline or semi-colon is within braces or brackets
602 3. A command consists of fields. The first field is the name of the command.
603 The other fields are strings that are passed to that command as arguments.
604 4. Fields are normally separated by white space.
605 5. Double-quotes allow white space and semi-colons to appear within
607 Command substitution, variable substitution, and backslash substitution
608 still occur inside quotes.
609 6. Braces defer interpretation of special characters.
610 If a field begins with a left brace, then it consists of everything
611 between the left brace and the matching right brace. The
612 braces themselves are not included in the argument.
613 No further processing is done on the information between the braces
614 except that backslash-newline sequences are eliminated.
615 7. If a field doesn't begin with a brace then backslash,
616 variable, and command substitution are done on the field. Only a
617 single level of processing is done: the results of one substitution
618 are not scanned again for further substitutions or any other
619 special treatment. Substitution can
620 occur on any field of a command, including the command name
621 as well as the arguments.
622 8. If the first non-blank character of a command is a +\#+, everything
623 from the +#+ up through the next newline is treated as a comment
628 The second major interpretation applied to strings in Tcl is
629 as expressions. Several commands, such as `expr`, `for`,
630 and `if`, treat one or more of their arguments as expressions
631 and call the Tcl expression processors ('Jim_ExprLong',
632 'Jim_ExprBoolean', etc.) to evaluate them.
634 The operators permitted in Tcl expressions are a subset of
635 the operators permitted in C expressions, and they have the
636 same meaning and precedence as the corresponding C operators.
637 Expressions almost always yield numeric results
638 (integer or floating-point values).
639 For example, the expression
645 Tcl expressions differ from C expressions in the way that
646 operands are specified, and in that Tcl expressions support
647 non-numeric operands and string comparisons.
649 A Tcl expression consists of a combination of operands, operators,
652 White space may be used between the operands and operators and
653 parentheses; it is ignored by the expression processor.
654 Where possible, operands are interpreted as integer values.
656 Integer values may be specified in decimal (the normal case), in octal (if the
657 first character of the operand is '0'), or in hexadecimal (if the first
658 two characters of the operand are '0x').
660 If an operand does not have one of the integer formats given
661 above, then it is treated as a floating-point number if that is
662 possible. Floating-point numbers may be specified in any of the
663 ways accepted by an ANSI-compliant C compiler (except that the
664 'f', 'F', 'l', and 'L' suffixes will not be permitted in
665 most installations). For example, all of the
666 following are valid floating-point numbers: 2.1, 3., 6e4, 7.91e+16.
668 If no numeric interpretation is possible, then an operand is left
669 as a string (and only a limited set of operators may be applied to
672 1. Operands may be specified in any of the following ways:
674 2. As a numeric value, either integer or floating-point.
676 3. As a Tcl variable, using standard '$' notation.
677 The variable's value will be used as the operand.
679 4. As a string enclosed in double-quotes.
680 The expression parser will perform backslash, variable, and
681 command substitutions on the information between the quotes,
682 and use the resulting value as the operand
684 5. As a string enclosed in braces.
685 The characters between the open brace and matching close brace
686 will be used as the operand without any substitutions.
688 6. As a Tcl command enclosed in brackets.
689 The command will be executed and its result will be used as
692 Where substitutions occur above (e.g. inside quoted strings), they
693 are performed by the expression processor.
694 However, an additional layer of substitution may already have
695 been performed by the command parser before the expression
696 processor was called.
698 As discussed below, it is usually best to enclose expressions
699 in braces to prevent the command parser from performing substitutions
702 For some examples of simple expressions, suppose the variable 'a' has
703 the value 3 and the variable 'b' has the value 6. Then the expression
704 on the left side of each of the lines below will evaluate to the value
705 on the right side of the line:
710 {word one} < "word $a" 0
712 The valid operators are listed below, grouped in decreasing order
714 [[OperatorPrecedence]]
715 +int() double() round() abs(), rand(), srand()+::
716 Unary functions (except rand() which takes no arguments)
717 * +'int()'+ converts the numeric argument to an integer by truncating down.
718 * +'double()'+ converts the numeric argument to floating point.
719 * +'round()'+ converts the numeric argument to the closest integer value.
720 * +'abs()'+ takes the absolute value of the numeric argument.
721 * +'rand()'+ takes the absolute value of the numeric argument.
722 * +'rand()'+ returns a pseudo-random floating-point value in the range (0,1).
723 * +'srand()'+ takes an integer argument to (re)seed the random number generator. Returns the first random number from that seed.
725 +sin() cos() tan() asin() acos() atan() sinh() cosh() tanh() ceil() floor() exp() log() log10() sqrt()+::
726 Unary math functions.
727 If Jim is compiled with math support, these functions are available.
730 Unary minus, unary plus, bit-wise NOT, logical NOT. None of these operands
731 may be applied to string operands, and bit-wise NOT may be
732 applied only to integers.
735 Power. e.g. 'x^y^'. If Jim is compiled with math support, supports doubles and
736 integers. Otherwise supports integers only. (Note that the math-function form
737 has the same highest precedence)
740 Multiply, divide, remainder. None of these operands may be
741 applied to string operands, and remainder may be applied only
745 Add and subtract. Valid for any numeric operands.
748 Left and right shift, left and right rotate. Valid for integer operands only.
751 Boolean less, greater, less than or equal, and greater than or equal.
752 Each operator produces 1 if the condition is true, 0 otherwise.
753 These operators may be applied to strings as well as numeric operands,
754 in which case string comparison is used.
757 Boolean equal and not equal. Each operator produces a zero/one result.
758 Valid for all operand types. *Note* that values will be converted to integers
759 if possible, then floating point types, and finally strings will be compared.
760 It is recommended that 'eq' and 'ne' should be used for string comparison.
763 String equal and not equal. Uses the string value directly without
764 attempting to convert to a number first.
767 String in list and not in list. For 'in', result is 1 if the left operand (as a string)
768 is contained in the right operand (as a list), or 0 otherwise. The result for
769 +{$a ni $list}+ is equivalent to +{!($a in $list)}+.
772 Bit-wise AND. Valid for integer operands only.
775 Bit-wise OR. Valid for integer operands only.
778 Bit-wise exclusive OR. Valid for integer operands only.
781 Logical AND. Produces a 1 result if both operands are non-zero, 0 otherwise.
782 Valid for numeric operands only (integers or floating-point).
785 Logical OR. Produces a 0 result if both operands are zero, 1 otherwise.
786 Valid for numeric operands only (integers or floating-point).
789 If-then-else, as in C. If +'x'+
790 evaluates to non-zero, then the result is the value of +'y'+.
791 Otherwise the result is the value of +'z'+.
792 The +'x'+ operand must have a numeric value, while +'y'+ and +'z'+ can
795 See the C manual for more details on the results
796 produced by each operator.
797 All of the binary operators group left-to-right within the same
798 precedence level. For example, the expression
804 The +&&+, +||+, and +?:+ operators have 'lazy evaluation', just as
805 in C, which means that operands are not evaluated if they are not
806 needed to determine the outcome. For example, in
810 only one of +[a]+ or +[b]+ will actually be evaluated,
811 depending on the value of +$v+.
813 All internal computations involving integers are done with the C
814 type 'long long' if available, or 'long' otherwise, and all internal
815 computations involving floating-point are done with the C type
818 When converting a string to floating-point, exponent overflow is
819 detected and results in a Tcl error.
820 For conversion to integer from string, detection of overflow depends
821 on the behaviour of some routines in the local C library, so it should
822 be regarded as unreliable.
823 In any case, overflow and underflow are generally not detected
824 reliably for intermediate results.
826 Conversion among internal representations for integer, floating-point,
827 and string operands is done automatically as needed.
828 For arithmetic computations, integers are used until some
829 floating-point number is introduced, after which floating-point is used.
834 yields the result 1, while
837 5 / ( [string length "abcd"] + 0.0 )
839 both yield the result 1.25.
841 String values may be used as operands of the comparison operators,
842 although the expression evaluator tries to do comparisons as integer
843 or floating-point when it can.
844 If one of the operands of a comparison is a string and the other
845 has a numeric value, the numeric operand is converted back to
846 a string using the C 'sprintf' format specifier
847 '%d' for integers and '%g' for floating-point values.
848 For example, the expressions
853 both evaluate to 1. The first comparison is done using integer
854 comparison, and the second is done using string comparison after
855 the second operand is converted to the string '18'.
857 In general it is safest to enclose an expression in braces when
858 entering it in a command: otherwise, if the expression contains
859 any white space then the Tcl interpreter will split it
860 among several arguments. For example, the command
864 results in three arguments being passed to `expr`: +$a+,
865 +\++, and +$b+. In addition, if the expression isn't in braces
866 then the Tcl interpreter will perform variable and command substitution
867 immediately (it will happen in the command parser rather than in
868 the expression parser). In many cases the expression is being
869 passed to a command that will evaluate the expression later (or
870 even many times if, for example, the expression is to be used to
871 decide when to exit a loop). Usually the desired goal is to re-do
872 the variable or command substitutions each time the expression is
873 evaluated, rather than once and for all at the beginning. For example,
876 for {set i 1} $i<=10 {incr i} {...} +** WRONG **+
878 is probably intended to iterate over all values of +i+ from 1 to 10.
879 After each iteration of the body of the loop, `for` will pass
880 its second argument to the expression evaluator to see whether or not
881 to continue processing. Unfortunately, in this case the value of +i+
882 in the second argument will be substituted once and for all when the
883 `for` command is parsed. If +i+ was 0 before the `for`
884 command was invoked then the second argument of `for` will be +0\<=10+
885 which will always evaluate to 1, even though +i+ eventually
886 becomes greater than 10. In the above case the loop will never
887 terminate. Instead, the expression should be placed in braces:
889 for {set i 1} {$i<=10} {incr i} {...} +** RIGHT **+
891 This causes the substitution of 'i'
892 to be delayed; it will be re-done each time the expression is
893 evaluated, which is the desired result.
897 The third major way that strings are interpreted in Tcl is as lists.
898 A list is just a string with a list-like structure
899 consisting of fields separated by white space. For example, the
904 is a list with four elements or fields.
905 Lists have the same basic structure as command strings, except
906 that a newline character in a list is treated as a field separator
907 just like space or tab. Conventions for braces and quotes
908 and backslashes are the same for lists as for commands. For example,
913 is a list with three elements: +a+, +b c+, and +d e {f g h}+.
915 Whenever an element is extracted from a list, the same rules about
916 braces and quotes and backslashes are applied as for commands. Thus in
917 the example above when the third element is extracted from the list,
922 (when the field was extracted, all that happened was to strip off
923 the outermost layer of braces). Command substitution and
924 variable substitution are never
925 made on a list (at least, not by the list-processing commands; the
926 list can always be passed to the Tcl interpreter for evaluation).
928 The Tcl commands `concat`, `foreach`, `lappend`, `lindex`, `linsert`,
929 `list`, `llength`, `lrange`, `lreplace`, `lsearch`, and `lsort` allow
930 you to build lists, extract elements from them, search them, and perform
931 other list-related functions.
933 Advanced list commands include `lrepeat`, `lreverse`, `lmap`, `lassign`, `lset`.
938 A new addition to Tcl 8.5 is the ability to expand a list into separate
939 arguments. Support for this feature is also available in Jim.
941 Consider the following attempt to exec a list:
946 This will attempt to exec the a command named "ls -l", which will clearly not
947 work. Typically eval and concat are required to solve this problem, however
948 it can be solved much more easily with +\{*\}+.
952 This will expand the following argument into individual elements and then evaluate
953 the resulting command.
955 Note that the official Tcl syntax is +\{*\}+, however +\{expand\}+ is retained
956 for backward compatibility with experimental versions of this feature.
960 Tcl provides two commands that support string matching using regular
961 expressions, `regexp` and `regsub`, as well as `switch -regexp` and
964 Regular expressions may be implemented one of two ways. Either using the system's C library
965 POSIX regular expression support, or using the built-in regular expression engine.
966 The differences between these are described below.
968 *NOTE* Tcl 7.x and 8.x use perl-style Advanced Regular Expressions (+ARE+).
970 POSIX Regular Expressions
971 ~~~~~~~~~~~~~~~~~~~~~~~~~
972 If the system supports POSIX regular expressions, and UTF-8 support is not enabled,
973 this support will be used by default. The type of regular expressions supported are
974 Extended Regular Expressions (+ERE+) rather than Basic Regular Expressions (+BRE+).
975 See REG_EXTENDED in the documentation.
977 Using the system-supported POSIX regular expressions will typically
978 make for the smallest code size, but some features such as UTF-8
979 and +{backslash}w+, +{backslash}d+, +{backslash}s+ are not supported.
981 See regex(3) and regex(7) for full details.
983 Jim built-in Regular Expressions
984 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
985 The Jim built-in regulare expression engine may be selected with +./configure --with-jim-regexp+
986 or it will be selected automatically if UTF-8 support is enabled.
988 This engine supports UTF-8 as well as some +ARE+ features. The differences with both Tcl 7.x/8.x
989 and POSIX are highlighted below.
991 1. UTF-8 strings and patterns are both supported
992 2. Supported character classes: +[:alnum:]+, +[:digit:]+ and +[:space:]+
993 3. Supported shorthand character classes: +{backslash}w = +[:alnum:]+, +{backslash}d+ = +[:digit:],+ +{backslash}s+ = +[:space:]+
994 4. Character classes apply to ASCII characters only
995 5. Supported constraint escapes: +{backslash}m+ = +{backslash}<+ = start of word, +{backslash}M+ = +{backslash}>+ = end of word
996 6. Backslash escapes may be used within regular expressions, such as +{backslash}n+ = newline, +{backslash}uNNNN+ = unicode
997 7. No support for the +?+ non-greedy quantifier. e.g. +*?+
1001 Each command produces two results: a code and a string. The
1002 code indicates whether the command completed successfully or not,
1003 and the string gives additional information. The valid codes are
1004 defined in jim.h, and are:
1007 This is the normal return code, and indicates that the command completed
1008 successfully. The string gives the command's return value.
1011 Indicates that an error occurred; the string gives a message describing
1015 Indicates that the `return` command has been invoked, and that the
1016 current procedure (or top-level command or `source` command)
1017 should return immediately. The
1018 string gives the return value for the procedure or command.
1021 Indicates that the `break` command has been invoked, so the
1022 innermost loop should abort immediately. The string should always
1026 Indicates that the `continue` command has been invoked, so the
1027 innermost loop should go on to the next iteration. The string
1028 should always be empty.
1031 Indicates that a signal was caught while executing a commands.
1032 The string contains the name of the signal caught.
1033 See the `signal` and `catch` commands.
1036 Indicates that the command called the `exit` command.
1037 The string contains the exit code.
1039 Tcl programmers do not normally need to think about return codes,
1040 since +JIM_OK+ is almost always returned. If anything else is returned
1041 by a command, then the Tcl interpreter immediately stops processing
1042 commands and returns to its caller. If there are several nested
1043 invocations of the Tcl interpreter in progress, then each nested
1044 command will usually return the error to its caller, until eventually
1045 the error is reported to the top-level application code. The
1046 application will then display the error message for the user.
1048 In a few cases, some commands will handle certain `error` conditions
1049 themselves and not return them upwards. For example, the `for`
1050 command checks for the +JIM_BREAK+ code; if it occurs, then `for`
1051 stops executing the body of the loop and returns +JIM_OK+ to its
1052 caller. The `for` command also handles +JIM_CONTINUE+ codes and the
1053 procedure interpreter handles +JIM_RETURN+ codes. The `catch`
1054 command allows Tcl programs to catch errors and handle them without
1055 aborting command interpretation any further.
1057 The `info returncodes` command may be used to programmatically map between
1058 return codes and names.
1062 Tcl allows you to extend the command interface by defining
1063 procedures. A Tcl procedure can be invoked just like any other Tcl
1064 command (it has a name and it receives one or more arguments).
1065 The only difference is that its body isn't a piece of C code linked
1066 into the program; it is a string containing one or more other
1069 The `proc` command is used to create a new Tcl command procedure:
1071 +*proc* 'name arglist ?statics? body'+
1073 The new command is named +'name'+, and it replaces any existing command
1074 there may have been by that name. Whenever the new command is
1075 invoked, the contents of +'body'+ will be executed by the Tcl
1078 +'arglist'+ specifies the formal arguments to the procedure.
1079 It consists of a list, possibly empty, of the following
1080 argument specifiers:
1083 Required Argument - A simple argument name.
1086 Optional Argument - A two-element list consisting of the
1087 argument name, followed by the default value, which will
1088 be used if the corresponding argument is not supplied.
1091 Reference Argument - The caller is expected to pass the name of
1092 an existing variable. An implicit `upvar 1 'origname' 'name'` is done
1093 to make the variable available in the proc scope.
1096 Variable Argument - The special name +'args'+, which is
1097 assigned all remaining arguments (including none) as a list. The
1098 variable argument may only be specified once. Note that
1099 the syntax +args newname+ may be used to retain the special
1100 behaviour of +'args'+ with a different local name. In this case,
1101 the variable is named +'newname'+ rather than +'args'+.
1103 When the command is invoked, a local variable will be created for each of
1104 the formal arguments to the procedure; its value will be the value
1105 of corresponding argument in the invoking command or the argument's
1108 Arguments with default values need not be specified in a procedure
1109 invocation. However, there must be enough actual arguments for all
1110 required arguments, and there must not be any extra actual arguments
1111 (unless the Variable Argument is specified).
1113 Actual arguments are assigned to formal arguments as in left-to-right
1114 order with the following precedence.
1116 1. Required Arguments (including Reference Arguments)
1117 2. Optional Arguments
1118 3. Variable Argument
1120 The following example illustrates precedence. Assume a procedure declaration:
1122 proc p {{a A} args b {c C} d} {...}
1124 This procedure requires at least two arguments, but can accept an unlimited number.
1125 The following table shows how various numbers of arguments are assigned.
1126 Values marked as +-+ are assigned the default value.
1128 [width="40%",frame="topbot",options="header"]
1130 |Number of arguments|a|args|b|c|d
1138 When +'body'+ is being executed, variable names normally refer to local
1139 variables, which are created automatically when referenced and deleted
1140 when the procedure returns. One local variable is automatically created
1141 for each of the procedure's arguments. Global variables can be
1142 accessed by invoking the `global` command or via the +::+ prefix.
1146 In addition to procedure arguments, Jim procedures may declare static variables.
1147 These variables scoped to the procedure and initialised at procedure definition.
1148 Either from the static variable definition, or from the enclosing scope.
1150 Consider the following example:
1153 jim> proc a {} {a {b 2}} {
1165 The static variable +'a'+ has no initialiser, so it is initialised from
1166 the enclosing scope with the value 1. (Note that it is an error if there
1167 is no variable with the same name in the enclosing scope). However +'b'+
1168 has an initialiser, so it is initialised to 2.
1170 Unlike a local variable, the value of a static variable is retained across
1171 invocations of the procedure.
1173 See the `proc` command for information on
1174 how to define procedures and what happens when they are invoked.
1176 VARIABLES - SCALARS AND ARRAYS
1177 ------------------------------
1178 Tcl allows the definition of variables and the use of their values
1179 either through '$'-style variable substitution, the `set`
1180 command, or a few other mechanisms.
1182 Variables need not be declared: a new variable will automatically
1183 be created each time a new variable name is used.
1185 Tcl supports two types of variables: scalars and arrays.
1186 A scalar variable has a single value, whereas an array variable
1187 can have any number of elements, each with a name (called
1188 its 'index') and a value.
1190 Array indexes may be arbitrary strings; they need not be numeric.
1191 Parentheses are used refer to array elements in Tcl commands.
1192 For example, the command
1196 will modify the element of 'x' whose index is 'first'
1197 so that its new value is '44'.
1199 Two-dimensional arrays can be simulated in Tcl by using indexes
1200 that contain multiple concatenated values.
1201 For example, the commands
1206 set the elements of 'a' whose indexes are '2,3' and '3,6'.
1208 In general, array elements may be used anywhere in Tcl that scalar
1209 variables may be used.
1211 If an array is defined with a particular name, then there may
1212 not be a scalar variable with the same name.
1214 Similarly, if there is a scalar variable with a particular
1215 name then it is not possible to make array references to the
1218 To convert a scalar variable to an array or vice versa, remove
1219 the existing variable with the `unset` command.
1221 The `array` command provides several features for dealing
1222 with arrays, such as querying the names of all the elements of
1223 the array and converting between an array and a list.
1225 Variables may be either global or local. If a variable
1226 name is used when a procedure isn't being executed, then it
1227 automatically refers to a global variable. Variable names used
1228 within a procedure normally refer to local variables associated with that
1229 invocation of the procedure. Local variables are deleted whenever
1230 a procedure exits. Either `global` command may be used to request
1231 that a name refer to a global variable for the duration of the current
1232 procedure (this is somewhat analogous to 'extern' in C), or the variable
1233 may be explicitly scoped with the +::+ prefix. For example
1249 ARRAYS AS LISTS IN JIM
1250 ----------------------
1251 Unlike Tcl, Jim can automatically convert between a list (with an even
1252 number of elements) and an array value. This is similar to the way Tcl
1253 can convert between a string and a list.
1264 Thus `array set` is equivalent to `set` when the variable does not
1267 The reverse is also true where an array will be converted into
1270 set a(1) one; set a(2) two
1279 Tcl 8.5 introduced the dict command, and Jim Tcl has added a version
1280 of this command. Dictionaries provide efficient access to key-value
1281 pairs, just like arrays, but dictionaries are pure values. This
1282 means that you can pass them to a procedure just as a list or a
1283 string. Tcl dictionaries are therefore much more like Tcl lists,
1284 except that they represent a mapping from keys to values, rather
1285 than an ordered sequence.
1287 You can nest dictionaries, so that the value for a particular key
1288 consists of another dictionary. That way you can elegantly build
1289 complicated data structures, such as hierarchical databases. You
1290 can also combine dictionaries with other Tcl data structures. For
1291 instance, you can build a list of dictionaries that themselves
1294 Dictionaries are values that contain an efficient, order-preserving
1295 mapping from arbitrary keys to arbitrary values. Each key in the
1296 dictionary maps to a single value. They have a textual format that
1297 is exactly that of any list with an even number of elements, with
1298 each mapping in the dictionary being represented as two items in
1299 the list. When a command takes a dictionary and produces a new
1300 dictionary based on it (either returning it or writing it back into
1301 the variable that the starting dictionary was read from) the new
1302 dictionary will have the same order of keys, modulo any deleted
1303 keys and with new keys added on to the end. When a string is
1304 interpreted as a dictionary and it would otherwise have duplicate
1305 keys, only the last value for a particular key is used; the others
1306 are ignored, meaning that, "apple banana" and "apple carrot apple
1307 banana" are equivalent dictionaries (with different string
1310 Note that in Jim, arrays are implemented as dictionaries.
1311 Thus automatic conversion between lists and dictionaries applies
1312 as it does for arrays.
1314 jim> dict set a 1 one
1316 jim> dict set a 2 two
1322 jim> dict set a 3 T three
1323 1 one 2 two 3 {T three}
1325 See the `dict` command for more details.
1327 GARBAGE COLLECTION, REFERENCES, LAMBDA
1328 --------------------------------------
1329 Unlike Tcl, Jim has some sophisticated support for functional programming.
1330 These are described briefly below.
1332 More information may be found at http://wiki.tcl.tk/13847
1336 A reference can be thought of as holding a value with one level of indirection,
1337 where the value may be garbage collected when unreferenced.
1338 Consider the following example:
1340 jim> set r [ref "One String" test]
1341 <reference.<test___>.00000000000000000000>
1345 The operation `ref` creates a references to the value specified by the
1346 first argument. (The second argument is a "type" used for documentation purposes).
1348 The operation `getref` is the dereferencing operation which retrieves the value
1349 stored in the reference.
1351 jim> setref $r "New String"
1356 The operation `setref` replaces the value stored by the reference. If the old value
1357 is no longer accessible by any reference, it will eventually be automatically be garbage
1362 Normally, all values in Tcl are passed by value. As such values are copied and released
1363 automatically as necessary.
1365 With the introduction of references, it is possible to create values whose lifetime
1366 transcend their scope. To support this, case, the Jim system will periodically identify
1367 and discard objects which are no longer accessible by any reference.
1369 The `collect` command may be used to force garbage collection. Consider a reference created
1372 jim> proc f {ref value} { puts "Finaliser called for $ref,$value" }
1373 jim> set r [ref "One String" test f]
1374 <reference.<test___>.00000000000
1379 Finaliser called for <reference.<test___>.00000000000,One String
1382 Note that once the reference, 'r', was modified so that it no longer
1383 contained a reference to the value, the garbage collector discarded
1384 the value (after calling the finalizer).
1386 The finalizer for a reference may be examined or changed with the `finalize` command
1390 jim> finalize $r newf
1395 Jim provides a garbage collected lambda function. This is a procedure
1396 which is able to create an anonymous procedure. Consider:
1398 jim> set f [lambda {a} {{x 0}} { incr x $a }]
1405 This create an anonymous procedure (with the name stored in 'f'), with a static variable
1406 which is incremented by the supplied value and the result returned.
1408 Once the procedure name is no longer accessible, it will automatically be deleted
1409 when the garbage collector runs.
1411 The procedure may also be delete immediately by renaming it "". e.g.
1417 If Jim is built with UTF-8 support enabled (configure --enable-utf),
1418 then most string-related commands become UTF-8 aware. These include,
1419 but are not limited to, `string match`, `split`, `glob`, `scan` and
1422 UTF-8 encoding has many advantages, but one of the complications is that
1423 characters can take a variable number of bytes. Thus the addition of
1424 `string bytelength` which returns the number of bytes in a string,
1425 while `string length` returns the number of characters.
1427 If UTF-8 support is not enabled, all commands treat bytes as characters
1428 and `string bytelength` returns the same value as `string length`.
1430 Note that even if UTF-8 support is not enabled, the +{backslash}uNNNN+ syntax
1431 is still available to embed UTF-8 sequences.
1435 Commands such as `string match`, `lsearch -glob`, `array names` and others use string
1436 pattern matching rules. These commands support UTF-8. For example:
1438 string match a\[\ua0-\ubf\]b "a\u00a3b"
1442 +format %c+ allows a unicode codepoint to be be encoded. For example, the following will return
1443 a string with two bytes and one character. The same as +{backslash}ub5+
1447 `format` respects widths as character widths, not byte widths. For example, the following will
1448 return a string with three characters, not three bytes.
1450 format %.3s \ub5\ub6\ub7\ub8
1452 Similarly, +scan ... %c+ allows a UTF-8 to be decoded to a unicode codepoint. The following will set
1453 +'a'+ to 181 (0xb5) and +'b'+ to 65 (0x41).
1455 scan \u00b5A %c%c a b
1457 `scan %s` will also accept a character class, including unicode ranges.
1461 `string is` has *not* been extended to classify UTF-8 characters. Therefore, the following
1462 will return 0, even though the string may be considered to be alphabetic.
1464 string is alpha \ub5Test
1466 This does not affect the string classes 'ascii', 'control', 'digit', 'double', 'integer' or 'xdigit'.
1468 Case Mapping and Conversion
1469 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
1470 Jim provides a simplified unicode case mapping. This means that case conversion
1471 and comparison will not increase or decrease the number of characters in a string.
1473 `string toupper` will convert any lowercase letters to their uppercase equivalent.
1474 Any character which is not a letter or has no uppercase equivalent is left unchanged.
1475 Similarly for `string tolower`.
1477 Commands which perform case insensitive matches, such as `string compare -nocase`
1478 and `lsearch -nocase` fold both strings to uppercase before comparison.
1480 Invalid UTF-8 Sequences
1481 ~~~~~~~~~~~~~~~~~~~~~~~
1482 Some UTF-8 character sequences are invalid, such as those beginning with '0xff',
1483 those which represent character sequences longer than 3 bytes (greater than U+FFFF),
1484 and those which end prematurely, such as a lone '0xc2'.
1486 In these situations, the offending bytes are treated as single characters. For example,
1487 the following returns 2.
1489 string bytelength \xff\xff
1493 If UTF-8 support is enabled, the built-in regular expression engine will be
1494 selected which supports UTF-8 strings and patterns.
1496 See REGULAR EXPRESSIONS
1500 The Tcl library provides the following built-in commands, which will
1501 be available in any application using Tcl. In addition to these
1502 built-in commands, there may be additional commands defined by each
1503 application, plus commands defined as Tcl procedures.
1505 In the command syntax descriptions below, words in +*boldface*+ are
1506 literals that you type verbatim to Tcl.
1508 Words in +'italics'+ are meta-symbols; they serve as names for any of
1509 a range of values that you can type.
1511 Optional arguments or groups of arguments are indicated by enclosing them
1512 in +?question-marks?+.
1514 Ellipses (+\...+) indicate that any number of additional
1515 arguments or groups of arguments may appear, in the same format
1516 as the preceding argument(s).
1527 Delivers the +SIGALRM+ signal to the process after the given
1528 number of seconds. If the platform supports 'ualarm(3)' then
1529 the argument may be a floating point value. Otherwise it must
1532 Note that unless a signal handler for +SIGALRM+ has been installed
1533 (see `signal`), the process will exit on this signal.
1537 +*alias* 'name args\...'+
1539 Creates a single word alias (`proc`) for one or more words. For example,
1540 the following creates an alias for the command `info exists`.
1547 `alias` returns +'name'+, allowing it to be used with `local`.
1549 See also `proc`, `curry`, `lambda`, `local`.
1553 +*append* 'varName value ?value value ...?'+
1555 Append all of the +'value'+ arguments to the current value
1556 of variable +'varName'+. If +'varName'+ doesn't exist,
1557 it is given a value equal to the concatenation of all the
1558 +'value'+ arguments.
1560 This command provides an efficient way to build up long
1561 variables incrementally.
1562 For example, "`append a $b`" is much more efficient than
1563 "`set a $a$b`" if +$a+ is long.
1567 +*array* 'option arrayName ?arg\...?'+
1569 This command performs one of several operations on the
1570 variable given by +'arrayName'+.
1572 Note that in general, if the named array does not exist, the +'array'+ command behaves
1573 as though the array exists but is empty.
1575 The +'option'+ argument determines what action is carried out by the
1576 command. The legal +'options'+ (which may be abbreviated) are:
1578 +*array exists* 'arrayName'+::
1579 Returns 1 if arrayName is an array variable, 0 if there is
1580 no variable by that name. This command is essentially
1581 identical to `info exists`
1583 +*array get* 'arrayName ?pattern?'+::
1584 Returns a list containing pairs of elements. The first
1585 element in each pair is the name of an element in arrayName
1586 and the second element of each pair is the value of the
1587 array element. The order of the pairs is undefined. If
1588 pattern is not specified, then all of the elements of the
1589 array are included in the result. If pattern is specified,
1590 then only those elements whose names match pattern (using
1591 the matching rules of string match) are included. If arrayName
1592 isn't the name of an array variable, or if the array contains
1593 no elements, then an empty list is returned.
1595 +*array names* 'arrayName ?pattern?'+::
1596 Returns a list containing the names of all of the elements
1597 in the array that match pattern. If pattern is omitted then
1598 the command returns all of the element names in the array.
1599 If pattern is specified, then only those elements whose
1600 names match pattern (using the matching rules of string
1601 match) are included. If there are no (matching) elements
1602 in the array, or if arrayName isn't the name of an array
1603 variable, then an empty string is returned.
1605 +*array set* 'arrayName list'+::
1606 Sets the values of one or more elements in arrayName. list
1607 must have a form like that returned by array get, consisting
1608 of an even number of elements. Each odd-numbered element
1609 in list is treated as an element name within arrayName, and
1610 the following element in list is used as a new value for
1611 that array element. If the variable arrayName does not
1612 already exist and list is empty, arrayName is created with
1613 an empty array value.
1615 +*array size* 'arrayName'+::
1616 Returns the number of elements in the array. If arrayName
1617 isn't the name of an array then 0 is returned.
1619 +*array unset* 'arrayName ?pattern?'+::
1620 Unsets all of the elements in the array that match pattern
1621 (using the matching rules of string match). If arrayName
1622 isn't the name of an array variable or there are no matching
1623 elements in the array, no error will be raised. If pattern
1624 is omitted and arrayName is an array variable, then the
1625 command unsets the entire array. The command always returns
1632 This command may be invoked only inside the body of a loop command
1633 such as `for` or `foreach` or `while`. It returns a +JIM_BREAK+ code
1634 to signal the innermost containing loop command to return immediately.
1638 +*case* 'string' ?in? 'patList body ?patList body ...?'+
1640 +*case* 'string' ?in? {'patList body ?patList body ...?'}+
1642 *Note* that the `switch` command should generally be preferred unless compatibility
1643 with Tcl 6.x is desired.
1645 Match +'string'+ against each of the +'patList'+ arguments
1646 in order. If one matches, then evaluate the following +'body'+ argument
1647 by passing it recursively to the Tcl interpreter, and return the result
1648 of that evaluation. Each +'patList'+ argument consists of a single
1649 pattern or list of patterns. Each pattern may contain any of the wild-cards
1650 described under `string match`.
1652 If a +'patList'+ argument is +default+, the corresponding body will be
1653 evaluated if no +'patList'+ matches +'string'+. If no +'patList'+ argument
1654 matches +'string'+ and no default is given, then the `case` command returns
1657 Two syntaxes are provided.
1659 The first uses a separate argument for each of the patterns and commands;
1660 this form is convenient if substitutions are desired on some of the
1661 patterns or commands.
1663 The second form places all of the patterns and commands together into
1664 a single argument; the argument must have proper list structure, with
1665 the elements of the list being the patterns and commands.
1667 The second form makes it easy to construct multi-line case commands,
1668 since the braces around the whole list make it unnecessary to include a
1669 backslash at the end of each line.
1671 Since the +'patList'+ arguments are in braces in the second form,
1672 no command or variable substitutions are performed on them; this makes
1673 the behaviour of the second form different than the first form in some
1676 Below are some examples of `case` commands:
1678 case abc in {a b} {format 1} default {format 2} a* {format 3}
1688 will return '1', and
1703 +*catch* ?-?no?'code \...'? ?--? 'command ?resultVarName? ?optionsVarName?'+
1705 The `catch` command may be used to prevent errors from aborting
1706 command interpretation. `catch` evaluates +'command'+, and returns a
1707 +JIM_OK+ code, regardless of any errors that might occur while
1708 executing +'command'+ (with the possible exception of +JIM_SIGNAL+ -
1711 The return value from `catch` is a decimal string giving the code
1712 returned by the Tcl interpreter after executing +'command'+. This
1713 will be '0' (+JIM_OK+) if there were no errors in +'command'+; otherwise
1714 it will have a non-zero value corresponding to one of the exceptional
1715 return codes (see jim.h for the definitions of code values, or the
1716 `info returncodes` command).
1718 If the +'resultVarName'+ argument is given, then it gives the name
1719 of a variable; `catch` will set the value of the variable to the
1720 string returned from +'command'+ (either a result or an error message).
1722 If the +'optionsVarName'+ argument is given, then it gives the name
1723 of a variable; `catch` will set the value of the variable to a
1724 dictionary. For any return code other than +JIM_RETURN+, the value
1725 for the key +-code+ will be set to the return code. For +JIM_RETURN+
1726 it will be set to the code given in `return -code`. Additionally,
1727 for the return code +JIM_ERR+, the value of the key +-errorinfo+
1728 will contain the current stack trace (the same result as `info stacktrace`),
1729 the value of the key +-errorcode+ will contain the
1730 same value as the global variable $::errorCode, and the value of
1731 the key +-level+ will be the current return level (see `return -level`).
1732 This can be useful to rethrow an error:
1734 if {[catch {...} msg opts]} {
1735 ...maybe do something with the error...
1737 return {*}$opts $msg
1740 Normally `catch` will +'not'+ catch any of the codes +JIM_EXIT+, +JIM_EVAL+ or +JIM_SIGNAL+.
1741 The set of codes which will be caught may be modified by specifying the one more codes before
1744 e.g. To catch +JIM_EXIT+ but not +JIM_BREAK+ or +JIM_CONTINUE+
1746 catch -exit -nobreak -nocontinue -- { ... }
1748 The use of +--+ is optional. It signifies that no more return code options follow.
1750 Note that if a signal marked as `signal handle` is caught with `catch -signal`, the return value
1751 (stored in +'resultVarName'+) is name of the signal caught.
1757 Change the current working directory to +'dirName'+.
1759 Returns an empty string.
1761 This command can potentially be disruptive to an application, so it may
1762 be removed in some applications.
1767 Returns the current time as seconds since the epoch.
1769 +*clock format* 'seconds' ?*-format* 'format?'+::
1770 Format the given time (seconds since the epoch) according to the given
1771 format. See strftime(3) for supported formats.
1772 If no format is supplied, "%c" is used.
1774 +*clock scan* 'str' *-format* 'format'+::
1775 Scan the given time string using the given format string.
1776 See strptime(3) for supported formats.
1784 Closes the file given by +'fileId'+.
1785 +'fileId'+ must be the return value from a previous invocation
1786 of the `open` command; after this command, it should not be
1793 Normally reference garbage collection is automatically performed periodically.
1794 However it may be run immediately with the `collect` command.
1796 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
1800 +*concat* 'arg ?arg \...?'+
1802 This command treats each argument as a list and concatenates them
1803 into a single list. It permits any number of arguments. For example,
1806 concat a b {c d e} {f {g h}}
1818 This command may be invoked only inside the body of a loop command such
1819 as `for` or `foreach` or `while`. It returns a +JIM_CONTINUE+ code to
1820 signal the innermost containing loop command to skip the remainder of
1821 the loop's body but continue with the next iteration of the loop.
1825 +*alias* 'args\...'+
1827 Similar to `alias` except it creates an anonymous procedure (lambda) instead of
1830 the following creates a local, unnamed alias for the command `info exists`.
1832 set e [local curry info exists]
1837 `curry` returns the name of the procedure.
1839 See also `proc`, `alias`, `lambda`, `local`.
1843 +*dict* 'option ?arg\...?'+
1845 Performs one of several operations on dictionary values.
1847 The +'option'+ argument determines what action is carried out by the
1848 command. The legal +'options'+ are:
1850 +*dict create* '?key value \...?'+::
1851 Create and return a new dictionary value that contains each of
1852 the key/value mappings listed as arguments (keys and values
1853 alternating, with each key being followed by its associated
1856 +*dict exists* 'dictionary key ?key \...?'+::
1857 Returns a boolean value indicating whether the given key (or path
1858 of keys through a set of nested dictionaries) exists in the given
1859 dictionary value. This returns a true value exactly when `dict get`
1860 on that path will succeed.
1862 +*dict get* 'dictionary ?key \...?'+::
1863 Given a dictionary value (first argument) and a key (second argument),
1864 this will retrieve the value for that key. Where several keys are
1865 supplied, the behaviour of the command shall be as if the result
1866 of "`dict get $dictVal $key`" was passed as the first argument to
1867 dict get with the remaining arguments as second (and possibly
1868 subsequent) arguments. This facilitates lookups in nested dictionaries.
1869 If no keys are provided, dict would return a list containing pairs
1870 of elements in a man- ner similar to array get. That is, the first
1871 element of each pair would be the key and the second element would
1872 be the value for that key. It is an error to attempt to retrieve
1873 a value for a key that is not present in the dictionary.
1875 +*dict keys* 'dictionary ?pattern?'+::
1876 Returns a list of the keys in the dictionary.
1877 If pattern is specified, then only those keys whose
1878 names match +'pattern'+ (using the matching rules of string
1879 match) are included.
1881 +*dict merge* ?'dictionary \...'?+::
1882 Return a dictionary that contains the contents of each of the
1883 +'dictionary'+ arguments. Where two (or more) dictionaries
1884 contain a mapping for the same key, the resulting dictionary
1885 maps that key to the value according to the last dictionary on
1886 the command line containing a mapping for that key.
1888 +*dict set* 'dictionaryName key ?key \...? value'+::
1889 This operation takes the +'name'+ of a variable containing a dictionary
1890 value and places an updated dictionary value in that variable
1891 containing a mapping from the given key to the given value. When
1892 multiple keys are present, this operation creates or updates a chain
1893 of nested dictionaries.
1895 +*dict size* 'dictionary'+::
1896 Return the number of key/value mappings in the given dictionary value.
1898 +*dict unset* 'dictionaryName key ?key \...? value'+::
1899 This operation (the companion to `dict set`) takes the name of a
1900 variable containing a dictionary value and places an updated
1901 dictionary value in that variable that does not contain a mapping
1902 for the given key. Where multiple keys are present, this describes
1903 a path through nested dictionaries to the mapping to remove. At
1904 least one key must be specified, but the last key on the key-path
1905 need not exist. All other components on the path must exist.
1907 +*dict with* 'dictionaryName key ?key \...? script'+::
1908 Execute the Tcl script in +'script'+ with the value for each
1909 key in +'dictionaryName'+ mapped to a variable with the same
1910 name. Where one or more keys are given, these indicate a chain
1911 of nested dictionaries, with the innermost dictionary being the
1912 one opened out for the execution of body. Making +'dictionaryName'+
1913 unreadable will make the updates to the dictionary be discarded,
1914 and this also happens if the contents of +'dictionaryName'+ are
1915 adjusted so that the chain of dictionaries no longer exists.
1916 The result of `dict with` is (unless some kind of error occurs)
1917 the result of the evaluation of body.
1919 The variables are mapped in the scope enclosing the `dict with`;
1920 it is recommended that this command only be used in a local
1921 scope (procedure). Because of this, the variables set by
1922 `dict with` will continue to exist after the command finishes (unless
1923 explicitly unset). Note that changes to the contents of +'dictionaryName'+
1924 only happen when +'script'+ terminates.
1928 +*env* '?name? ?default?'+
1930 If +'name'+ is supplied, returns the value of +'name'+ from the initial
1931 environment (see getenv(3)). An error is returned if +'name'+ does not
1932 exist in the environment, unless +'default'+ is supplied - in which case
1933 that value is returned instead.
1935 If no arguments are supplied, returns a list of all environment variables
1936 and their values as +{name value \...}+
1938 See also the global variable +::env+
1946 Returns 1 if an end-of-file condition has occurred on +'fileId'+,
1949 +'fileId'+ must have been the return value from a previous call to `open`,
1950 or it may be +stdin+, +stdout+, or +stderr+ to refer to one of the
1951 standard I/O channels.
1955 +*error* 'message ?stacktrace?'+
1957 Returns a +JIM_ERR+ code, which causes command interpretation to be
1958 unwound. +'message'+ is a string that is returned to the application
1959 to indicate what went wrong.
1961 If the +'stacktrace'+ argument is provided and is non-empty,
1962 it is used to initialize the stacktrace.
1964 This feature is most useful in conjunction with the `catch` command:
1965 if a caught error cannot be handled successfully, +'stacktrace'+ can be used
1966 to return a stack trace reflecting the original point of occurrence
1971 error $errMsg [info stacktrace]
1973 See also `errorInfo`, `info stacktrace`, `catch` and `return`
1977 +*errorInfo* 'error ?stacktrace?'+
1979 Returns a human-readable representation of the given error message and stack trace.
1982 if {[catch {...} error]} {
1983 puts stderr [errorInfo $error [info stacktrace]]
1991 +*eval* 'arg ?arg\...?'+
1993 `eval` takes one or more arguments, which together comprise a Tcl
1994 command (or collection of Tcl commands separated by newlines in the
1995 usual way). `eval` concatenates all its arguments in the same
1996 fashion as the `concat` command, passes the concatenated string to the
1997 Tcl interpreter recursively, and returns the result of that
1998 evaluation (or any error generated by it).
2002 +*exec* 'arg ?arg\...?'+
2004 This command treats its arguments as the specification
2005 of one or more UNIX commands to execute as subprocesses.
2006 The commands take the form of a standard shell pipeline;
2007 +|+ arguments separate commands in the
2008 pipeline and cause standard output of the preceding command
2009 to be piped into standard input of the next command (or +|&+ for
2010 both standard output and standard error).
2012 Under normal conditions the result of the `exec` command
2013 consists of the standard output produced by the last command
2016 If any of the commands in the pipeline exit abnormally or
2017 are killed or suspended, then `exec` will return an error
2018 and the error message will include the pipeline's output followed by
2019 error messages describing the abnormal terminations.
2021 If any of the commands writes to its standard error file,
2022 then `exec` will return an error, and the error message
2023 will include the pipeline's output, followed by messages
2024 about abnormal terminations (if any), followed by the standard error
2027 If the last character of the result or error message
2028 is a newline then that character is deleted from the result
2029 or error message for consistency with normal
2032 An +'arg'+ may have one of the following special forms:
2035 The standard output of the last command in the pipeline
2036 is redirected to the file. In this situation `exec`
2037 will normally return an empty string.
2040 As above, but append to the file.
2043 The standard output of the last command in the pipeline is
2044 redirected to the given (writable) file descriptor (e.g. stdout,
2045 stderr, or the result of `open`). In this situation `exec`
2046 will normally return an empty string.
2049 The standard error of the last command in the pipeline
2050 is redirected to the file.
2053 As above, but append to the file.
2056 The standard error of the last command in the pipeline is
2057 redirected to the given (writable) file descriptor.
2060 The standard error of the last command in the pipeline is
2061 redirected to the same file descriptor as the standard output.
2064 Both the standard output and standard error of the last command
2065 in the pipeline is redirected to the file.
2068 As above, but append to the file.
2071 The standard input of the first command in the pipeline
2072 is taken from the file.
2075 The standard input of the first command is taken as the
2076 given immediate value.
2079 The standard input of the first command in the pipeline
2080 is taken from the given (readable) file descriptor.
2082 If there is no redirection of standard input, standard error
2083 or standard output, these are connected to the corresponding
2084 input or output of the application.
2086 If the last +'arg'+ is +&+ then the command will be
2087 executed in background.
2088 In this case the standard output from the last command
2089 in the pipeline will
2090 go to the application's standard output unless
2091 redirected in the command, and error output from all
2092 the commands in the pipeline will go to the application's
2093 standard error file. The return value of exec in this case
2094 is a list of process ids (pids) in the pipeline.
2096 Each +'arg'+ becomes one word for a command, except for
2097 +|+, +<+, +<<+, +>+, and +&+ arguments, and the
2098 arguments that follow +<+, +<<+, and +>+.
2100 The first word in each command is taken as the command name;
2101 the directories in the PATH environment variable are searched for
2102 an executable by the given name.
2104 No `glob` expansion or other shell-like substitutions
2105 are performed on the arguments to commands.
2107 If the command fails, the global $::errorCode (and the -errorcode
2108 option in `catch`) will be set to a list, as follows:
2110 +*CHILDKILLED* 'pid sigName msg'+::
2111 This format is used when a child process has been killed
2112 because of a signal. The pid element will be the process's
2113 identifier (in decimal). The sigName element will be the
2114 symbolic name of the signal that caused the process to
2115 terminate; it will be one of the names from the include
2116 file signal.h, such as SIGPIPE. The msg element will be a
2117 short human-readable message describing the signal, such
2118 as "write on pipe with no readers" for SIGPIPE.
2120 +*CHILDSUSP* 'pid sigName msg'+::
2121 This format is used when a child process has been suspended
2122 because of a signal. The pid element will be the process's
2123 identifier, in decimal. The sigName element will be the
2124 symbolic name of the signal that caused the process to
2125 suspend; this will be one of the names from the include
2126 file signal.h, such as SIGTTIN. The msg element will be a
2127 short human-readable message describing the signal, such
2128 as "background tty read" for SIGTTIN.
2130 +*CHILDSTATUS* 'pid code'+::
2131 This format is used when a child process has exited with a
2132 non-zero exit status. The pid element will be the process's
2133 identifier (in decimal) and the code element will be the
2134 exit code returned by the process (also in decimal).
2136 The environment for the executed command is set from $::env (unless
2137 this variable is unset, in which case the original environment is used).
2141 +*exists ?-var|-proc|-command?* 'name'+
2143 Checks the existence of the given variable, procedure or command
2144 respectively and returns 1 if it exists or 0 if not. This command
2145 provides a more simplified/convenient version of `info exists`,
2146 `info procs` and `info commands`.
2148 If the type is omitted, a type of '-var' is used. The type may be abbreviated.
2152 +*exit* '?returnCode?'+
2154 Terminate the process, returning +'returnCode'+ to the
2155 parent as the exit status.
2157 If +'returnCode'+ isn't specified then it defaults
2160 Note that exit can be caught with `catch`.
2166 Calls the expression processor to evaluate +'arg'+, and returns
2167 the result as a string. See the section EXPRESSIONS above.
2169 Note that Jim supports a shorthand syntax for `expr` as +$(\...)+
2170 The following two are identical.
2172 set x [expr {3 * 2 + 1}]
2177 +*file* 'option name ?arg\...?'+
2179 Operate on a file or a file name. +'name'+ is the name of a file.
2181 +'option'+ indicates what to do with the file name. Any unique
2182 abbreviation for +'option'+ is acceptable. The valid options are:
2184 +*file atime* 'name'+::
2185 Return a decimal string giving the time at which file +'name'+
2186 was last accessed. The time is measured in the standard UNIX
2187 fashion as seconds from a fixed starting time (often January 1, 1970).
2188 If the file doesn't exist or its access time cannot be queried then an
2191 +*file copy ?-force?* 'source target'+::
2192 Copies file +'source'+ to file +'target'+. The source file must exist.
2193 The target file must not exist, unless +-force+ is specified.
2195 +*file delete ?-force?* 'name\...'+::
2196 Deletes file or directory +'name'+. If the file or directory doesn't exist, nothing happens.
2197 If it can't be deleted, an error is generated. Non-empty directories will not be deleted
2198 unless the +-force+ options is given. In this case no errors will be generated, even
2199 if the file/directory can't be deleted.
2201 +*file dirname* 'name'+::
2202 Return all of the characters in +'name'+ up to but not including
2203 the last slash character. If there are no slashes in +'name'+
2204 then return +.+ (a single dot). If the last slash in +'name'+ is its first
2205 character, then return +/+.
2207 +*file executable* 'name'+::
2208 Return '1' if file +'name'+ is executable by
2209 the current user, '0' otherwise.
2211 +*file exists* 'name'+::
2212 Return '1' if file +'name'+ exists and the current user has
2213 search privileges for the directories leading to it, '0' otherwise.
2215 +*file extension* 'name'+::
2216 Return all of the characters in +'name'+ after and including the
2217 last dot in +'name'+. If there is no dot in +'name'+ then return
2220 +*file isdirectory* 'name'+::
2221 Return '1' if file +'name'+ is a directory,
2224 +*file isfile* 'name'+::
2225 Return '1' if file +'name'+ is a regular file,
2228 +*file join* 'arg\...'+::
2229 Joins multiple path components. Note that if any components is
2230 an absolute path, the preceding components are ignored.
2231 Thus +"`file` join /tmp /root"+ returns +"/root"+.
2233 +*file lstat* 'name varName'+::
2234 Same as 'stat' option (see below) except uses the +'lstat'+
2235 kernel call instead of +'stat'+. This means that if +'name'+
2236 refers to a symbolic link the information returned in +'varName'+
2237 is for the link rather than the file it refers to. On systems that
2238 don't support symbolic links this option behaves exactly the same
2239 as the 'stat' option.
2241 +*file mkdir* 'dir1 ?dir2\...?'+::
2242 Creates each directory specified. For each pathname +'dir'+ specified,
2243 this command will create all non-existing parent directories
2244 as well as +'dir'+ itself. If an existing directory is specified,
2245 then no action is taken and no error is returned. Trying to
2246 overwrite an existing file with a directory will result in an
2247 error. Arguments are processed in the order specified, halting
2248 at the first error, if any.
2250 +*file mtime* 'name ?time?'+::
2251 Return a decimal string giving the time at which file +'name'+
2252 was last modified. The time is measured in the standard UNIX
2253 fashion as seconds from a fixed starting time (often January 1, 1970).
2254 If the file doesn't exist or its modified time cannot be queried then an
2255 error is generated. If +'time'+ is given, sets the modification time
2256 of the file to the given value.
2258 +*file normalize* 'name'+::
2259 Return the normalized path of +'name'+. See 'realpath(3)'.
2261 +*file owned* 'name'+::
2262 Return '1' if file +'name'+ is owned by the current user,
2265 +*file readable* 'name'+::
2266 Return '1' if file +'name'+ is readable by
2267 the current user, '0' otherwise.
2269 +*file readlink* 'name'+::
2270 Returns the value of the symbolic link given by +'name'+ (i.e. the
2271 name of the file it points to). If
2272 +'name'+ isn't a symbolic link or its value cannot be read, then
2273 an error is returned. On systems that don't support symbolic links
2274 this option is undefined.
2276 +*file rename* 'oldname' 'newname'+::
2277 Renames the file from the old name to the new name.
2279 +*file rootname* 'name'+::
2280 Return all of the characters in +'name'+ up to but not including
2281 the last '.' character in the name. If +'name'+ doesn't contain
2282 a dot, then return +'name'+.
2284 +*file size* 'name'+::
2285 Return a decimal string giving the size of file +'name'+ in bytes.
2286 If the file doesn't exist or its size cannot be queried then an
2289 +*file stat* 'name varName'+::
2290 Invoke the 'stat' kernel call on +'name'+, and use the
2291 variable given by +'varName'+ to hold information returned from
2293 +'varName'+ is treated as an array variable,
2294 and the following elements of that variable are set: 'atime',
2295 'ctime', 'dev', 'gid', 'ino', 'mode', 'mtime',
2296 'nlink', 'size', 'type', 'uid'.
2297 Each element except 'type' is a decimal string with the value of
2298 the corresponding field from the 'stat' return structure; see the
2299 manual entry for 'stat' for details on the meanings of the values.
2300 The 'type' element gives the type of the file in the same form
2301 returned by the command `file type`.
2302 This command returns an empty string.
2304 +*file tail* 'name'+::
2305 Return all of the characters in +'name'+ after the last slash.
2306 If +'name'+ contains no slashes then return +'name'+.
2308 +*file tempfile* '?template?'+::
2309 Creates and returns the name of a unique temporary file. If +'template'+ is omitted, a
2310 default template will be used to place the file in /tmp. See 'mkstemp(3)' for
2311 the format of the template and security concerns.
2313 +*file type* 'name'+::
2314 Returns a string giving the type of file +'name'+, which will be
2315 one of +file+, +directory+, +characterSpecial+,
2316 +blockSpecial+, +fifo+, +link+, or +socket+.
2318 +*file writable* 'name'+::
2319 Return '1' if file +'name'+ is writable by
2320 the current user, '0' otherwise.
2322 The `file` commands that return 0/1 results are often used in
2323 conditional or looping commands, for example:
2325 if {![file exists foo]} {
2326 error {bad file name}
2333 +*finalize* 'reference ?command?'+
2335 If +'command'+ is omitted, returns the finalizer command for the given reference.
2337 Otherwise, sets a new finalizer command for the given reference. +'command'+ may be
2338 the empty string to remove the current finalizer.
2340 The reference must be a valid reference create with the `ref`
2343 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
2351 Flushes any output that has been buffered for +'fileId'+. +'fileId'+ must
2352 have been the return value from a previous call to `open`, or it may be
2353 +stdout+ or +stderr+ to access one of the standard I/O streams; it must
2354 refer to a file that was opened for writing. This command returns an
2359 +*for* 'start test next body'+
2361 `for` is a looping command, similar in structure to the C `for` statement.
2362 The +'start'+, +'next'+, and +'body'+ arguments must be Tcl command strings,
2363 and +'test'+ is an expression string.
2365 The `for` command first invokes the Tcl interpreter to execute +'start'+.
2366 Then it repeatedly evaluates +'test'+ as an expression; if the result is
2367 non-zero it invokes the Tcl interpreter on +'body'+, then invokes the Tcl
2368 interpreter on +'next'+, then repeats the loop. The command terminates
2369 when +'test'+ evaluates to 0.
2371 If a `continue` command is invoked within +'body'+ then any remaining
2372 commands in the current execution of +'body'+ are skipped; processing
2373 continues by invoking the Tcl interpreter on +'next'+, then evaluating
2374 +'test'+, and so on.
2376 If a `break` command is invoked within +'body'+ or +'next'+, then the `for`
2377 command will return immediately.
2379 The operation of `break` and `continue` are similar to the corresponding
2382 `for` returns an empty string.
2386 +*foreach* 'varName list body'+
2388 +*foreach* 'varList list ?varList2 list2 \...? body'+
2390 In this command, +'varName'+ is the name of a variable, +'list'+
2391 is a list of values to assign to +'varName'+, and +'body'+ is a
2392 collection of Tcl commands.
2394 For each field in +'list'+ (in order from left to right), `foreach` assigns
2395 the contents of the field to +'varName'+ (as if the `lindex` command
2396 had been used to extract the field), then calls the Tcl interpreter to
2399 If instead of being a simple name, +'varList'+ is used, multiple assignments
2400 are made each time through the loop, one for each element of +'varList'+.
2402 For example, if there are two elements in +'varList'+ and six elements in
2403 the list, the loop will be executed three times.
2405 If the length of the list doesn't evenly divide by the number of elements
2406 in +'varList'+, the value of the remaining variables in the last iteration
2407 of the loop are undefined.
2409 The `break` and `continue` statements may be invoked inside +'body'+,
2410 with the same effect as in the `for` command.
2412 `foreach` returns an empty string.
2416 +*format* 'formatString ?arg \...?'+
2418 This command generates a formatted string in the same way as the
2419 C 'sprintf' procedure (it uses 'sprintf' in its
2420 implementation). +'formatString'+ indicates how to format
2421 the result, using +%+ fields as in 'sprintf', and the additional
2422 arguments, if any, provide values to be substituted into the result.
2424 All of the 'sprintf' options are valid; see the 'sprintf'
2425 man page for details. Each +'arg'+ must match the expected type
2426 from the +%+ field in +'formatString'+; the `format` command
2427 converts each argument to the correct type (floating, integer, etc.)
2428 before passing it to 'sprintf' for formatting.
2430 The only unusual conversion is for +%c+; in this case the argument
2431 must be a decimal string, which will then be converted to the corresponding
2432 ASCII character value.
2434 `format` does backslash substitution on its +'formatString'+
2435 argument, so backslash sequences in +'formatString'+ will be handled
2436 correctly even if the argument is in braces.
2438 The return value from `format` is the formatted string.
2442 +*getref* 'reference'+
2444 Returns the string associated with +'reference'+. The reference must
2445 be a valid reference create with the `ref` command.
2447 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
2451 +*gets* 'fileId ?varName?'+
2453 +'fileId' *gets* '?varName?'+
2455 Reads the next line from the file given by +'fileId'+ and discards
2456 the terminating newline character.
2458 If +'varName'+ is specified, then the line is placed in the variable
2459 by that name and the return value is a count of the number of characters
2460 read (not including the newline).
2462 If the end of the file is reached before reading
2463 any characters then -1 is returned and +'varName'+ is set to an
2466 If +'varName'+ is not specified then the return value will be
2467 the line (minus the newline character) or an empty string if
2468 the end of the file is reached before reading any characters.
2470 An empty string will also be returned if a line contains no characters
2471 except the newline, so `eof` may have to be used to determine
2472 what really happened.
2474 If the last character in the file is not a newline character, then
2475 `gets` behaves as if there were an additional newline character
2476 at the end of the file.
2478 +'fileId'+ must be +stdin+ or the return value from a previous
2479 call to `open`; it must refer to a file that was opened
2484 +*glob* ?*-nocomplain*? 'pattern ?pattern \...?'+
2486 This command performs filename globbing, using csh rules. The returned
2487 value from `glob` is the list of expanded filenames.
2489 If +-nocomplain+ is specified as the first argument then an empty
2490 list may be returned; otherwise an error is returned if the expanded
2491 list is empty. The +-nocomplain+ argument must be provided
2492 exactly: an abbreviation will not be accepted.
2497 +*global* 'varName ?varName \...?'+
2499 This command is ignored unless a Tcl procedure is being interpreted.
2500 If so, then it declares each given +'varName'+ to be a global variable
2501 rather than a local one. For the duration of the current procedure
2502 (and only while executing in the current procedure), any reference to
2503 +'varName'+ will be bound to a global variable instead
2506 An alternative to using `global` is to use the +::+ prefix
2507 to explicitly name a variable in the global scope.
2511 +*if* 'expr1' ?*then*? 'body1' *elseif* 'expr2' ?*then*? 'body2' *elseif* \... ?*else*? ?'bodyN'?+
2513 The `if` command evaluates +'expr1'+ as an expression (in the same way
2514 that `expr` evaluates its argument). The value of the expression must
2515 be numeric; if it is non-zero then +'body1'+ is executed by passing it to
2516 the Tcl interpreter.
2518 Otherwise +'expr2'+ is evaluated as an expression and if it is non-zero
2519 then +'body2'+ is executed, and so on.
2521 If none of the expressions evaluates to non-zero then +'bodyN'+ is executed.
2523 The +then+ and +else+ arguments are optional "noise words" to make the
2524 command easier to read.
2526 There may be any number of +elseif+ clauses, including zero. +'bodyN'+
2527 may also be omitted as long as +else+ is omitted too.
2529 The return value from the command is the result of the body script that
2530 was executed, or an empty string if none of the expressions was non-zero
2531 and there was no +'bodyN'+.
2535 +*incr* 'varName ?increment?'+
2537 Increment the value stored in the variable whose name is +'varName'+.
2538 The value of the variable must be integral.
2540 If +'increment'+ is supplied then its value (which must be an
2541 integer) is added to the value of variable +'varName'+; otherwise
2542 1 is added to +'varName'+.
2544 The new value is stored as a decimal string in variable +'varName'+
2545 and also returned as result.
2547 If the variable does not exist, the variable is implicitly created
2548 and set to +0+ first.
2553 +*info* 'option ?arg\...?'+::
2555 Provide information about various internals to the Tcl interpreter.
2556 The legal +'option'+'s (which may be abbreviated) are:
2558 +*info args* 'procname'+::
2559 Returns a list containing the names of the arguments to procedure
2560 +'procname'+, in order. +'procname'+ must be the name of a
2561 Tcl command procedure.
2563 +*info body* 'procname'+::
2564 Returns the body of procedure +'procname'+. +'procname'+ must be
2565 the name of a Tcl command procedure.
2568 Returns a list of all open file handles from `open` or `socket`
2570 +*info commands* ?'pattern'?+::
2571 If +'pattern'+ isn't specified, returns a list of names of all the
2572 Tcl commands, including both the built-in commands written in C and
2573 the command procedures defined using the `proc` command.
2574 If +'pattern'+ is specified, only those names matching +'pattern'+
2575 are returned. Matching is determined using the same rules as for
2578 +*info complete* 'command' ?'missing'?+::
2579 Returns 1 if +'command'+ is a complete Tcl command in the sense of
2580 having no unclosed quotes, braces, brackets or array element names,
2581 If the command doesn't appear to be complete then 0 is returned.
2582 This command is typically used in line-oriented input environments
2583 to allow users to type in commands that span multiple lines; if the
2584 command isn't complete, the script can delay evaluating it until additional
2585 lines have been typed to complete the command. If +'varName'+ is specified, the
2586 missing character is stored in the variable with that name.
2588 +*info exists* 'varName'+::
2589 Returns '1' if the variable named +'varName'+ exists in the
2590 current context (either as a global or local variable), returns '0'
2593 +*info frame* ?'number'?+::
2594 If +'number'+ is not specified, this command returns a number
2595 which is the same result as `info level` - the current stack frame level.
2596 If +'number'+ is specified, then the result is a list consisting of the procedure,
2597 filename and line number for the procedure call at level +'number'+ on the stack.
2598 If +'number'+ is positive then it selects a particular stack level (1 refers
2599 to the top-most active procedure, 2 to the procedure it called, and
2600 so on); otherwise it gives a level relative to the current level
2601 (0 refers to the current procedure, -1 to its caller, and so on).
2602 The level has an identical meaning to `info level`.
2604 +*info globals* ?'pattern'?+::
2605 If +'pattern'+ isn't specified, returns a list of all the names
2606 of currently-defined global variables.
2607 If +'pattern'+ is specified, only those names matching +'pattern'+
2608 are returned. Matching is determined using the same rules as for
2612 An alias for `os.gethostname` for compatibility with Tcl 6.x
2614 +*info level* ?'number'?+::
2615 If +'number'+ is not specified, this command returns a number
2616 giving the stack level of the invoking procedure, or 0 if the
2617 command is invoked at top-level. If +'number'+ is specified,
2618 then the result is a list consisting of the name and arguments for the
2619 procedure call at level +'number'+ on the stack. If +'number'+
2620 is positive then it selects a particular stack level (1 refers
2621 to the top-most active procedure, 2 to the procedure it called, and
2622 so on); otherwise it gives a level relative to the current level
2623 (0 refers to the current procedure, -1 to its caller, and so on).
2624 See the `uplevel` command for more information on what stack
2627 +*info locals* ?'pattern'?+::
2628 If +'pattern'+ isn't specified, returns a list of all the names
2629 of currently-defined local variables, including arguments to the
2630 current procedure, if any. Variables defined with the `global`
2631 and `upvar` commands will not be returned. If +'pattern'+ is
2632 specified, only those names matching +'pattern'+ are returned.
2633 Matching is determined using the same rules as for `string match`.
2635 +*info nameofexecutable*+::
2636 Returns the name of the binary file from which the application
2637 was invoked. A full path will be returned, unless the path
2638 can't be determined, in which case the empty string will be returned.
2640 +*info procs* ?'pattern'?+::
2641 If +'pattern'+ isn't specified, returns a list of all the
2642 names of Tcl command procedures.
2643 If +'pattern'+ is specified, only those names matching +'pattern'+
2644 are returned. Matching is determined using the same rules as for
2647 +*info references*+::
2648 Returns a list of all references which have not yet been garbage
2651 +*info returncodes* ?'code'?+::
2652 Returns a list representing the mapping of standard return codes
2653 to names. e.g. +{0 ok 1 error 2 return \...}+. If a code is given,
2654 instead returns the name for the given code.
2657 If a Tcl script file is currently being evaluated (i.e. there is a
2658 call to 'Jim_EvalFile' active or there is an active invocation
2659 of the `source` command), then this command returns the name
2660 of the innermost file being processed. Otherwise the command returns an
2663 +*info source* 'script'+::
2664 Returns the original source location of the given script as a list of
2665 +{filename linenumber}+. If the source location can't be determined, the
2666 list +{{} 0}+ is returned.
2668 +*info stacktrace*+::
2669 After an error is caught with `catch`, returns the stack trace as a list
2670 of +{procedure filename line \...}+.
2673 Returns the version number for this version of Jim in the form +*x.yy*+.
2675 +*info vars* ?'pattern'?+::
2676 If +'pattern'+ isn't specified,
2677 returns a list of all the names of currently-visible variables, including
2678 both locals and currently-visible globals.
2679 If +'pattern'+ is specified, only those names matching +'pattern'+
2680 are returned. Matching is determined using the same rules as for
2685 +*join* 'list ?joinString?'+
2687 The +'list'+ argument must be a valid Tcl list. This command returns the
2688 string formed by joining all of the elements of +'list'+ together with
2689 +'joinString'+ separating each adjacent pair of elements.
2691 The +'joinString'+ argument defaults to a space character.
2695 +*kill* ?'SIG'|*-0*? 'pid'+
2697 Sends the given signal to the process identified by +'pid'+.
2699 The signal may be specified by name or number in one of the following forms:
2707 The signal name may be in either upper or lower case.
2709 The special signal name +-0+ simply checks that a signal +'could'+ be sent.
2711 If no signal is specified, SIGTERM is used.
2713 An error is raised if the signal could not be delivered.
2717 +*lambda* 'args ?statics? body'+
2719 The `lambda` command is identical to `proc`, except rather than
2720 creating a named procedure, it creates an anonymous procedure and returns
2721 the name of the procedure.
2723 See `proc` and GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
2727 +*lappend* 'varName value ?value value \...?'+
2729 Treat the variable given by +'varName'+ as a list and append each of
2730 the +'value'+ arguments to that list as a separate element, with spaces
2733 If +'varName'+ doesn't exist, it is created as a list with elements given
2734 by the +'value'+ arguments. `lappend` is similar to `append` except that
2735 each +'value'+ is appended as a list element rather than raw text.
2737 This command provides a relatively efficient way to build up large lists.
2742 is much more efficient than
2744 set a [concat $a [list $b]]
2750 +*lassign* 'list varName ?varName \...?'+
2752 This command treats the value +'list'+ as a list and assigns successive elements from that list to
2753 the variables given by the +'varName'+ arguments in order. If there are more variable names than
2754 list elements, the remaining variables are set to the empty string. If there are more list ele-
2755 ments than variables, a list of unassigned elements is returned.
2757 jim> lassign {1 2 3} a b; puts a=$a,b=$b
2765 Executes it's arguments as a command (per `eval`) and considers the return
2766 value to be a procedure name, which is marked as having local scope.
2767 This means that when the current procedure exits, the specified
2768 procedure is deleted. This can be useful with `lambda` or simply
2771 In addition, if a command already exists with the same name,
2772 the existing command will be kept rather than deleted, and may be called
2773 via `upcall`. The previous command will be restored when the current
2774 command is deleted. See `upcall` for more details.
2776 In this example, a local procedure is created. Note that the procedure
2777 continues to have global scope while it is active.
2780 # proc ... returns "inner" which is marked local
2781 local proc inner {} {
2782 # will be deleted when 'outer' exits
2789 In this example, the lambda is deleted at the end of the procedure rather
2790 than waiting until garbage collection.
2793 set x [lambda inner {args} {
2794 # will be deleted when 'outer' exits
2796 # Use 'function' here which simply returns $x
2805 +*loop* 'var first limit ?incr? body'+
2807 Similar to `for` except simpler and possibly more efficient.
2808 With a positive increment, equivalent to:
2810 for {set var $first} {$var < $limit} {incr var $incr} $body
2812 If +'incr'+ is not specified, 1 is used.
2813 Note that setting the loop variable inside the loop does not
2814 affect the loop count.
2818 +*lindex* 'list index'+
2820 Treats +'list'+ as a Tcl list and returns element +'index'+ from it
2821 (0 refers to the first element of the list).
2822 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2824 In extracting the element, +'lindex'+ observes the same rules concerning
2825 braces and quotes and backslashes as the Tcl command interpreter; however,
2826 variable substitution and command substitution do not occur.
2828 If +'index'+ is negative or greater than or equal to the number of elements
2829 in +'value'+, then an empty string is returned.
2833 +*linsert* 'list index element ?element element \...?'+
2835 This command produces a new list from +'list'+ by inserting all
2836 of the +'element'+ arguments just before the element +'index'+
2837 of +'list'+. Each +'element'+ argument will become
2838 a separate element of the new list. If +'index'+ is less than
2839 or equal to zero, then the new elements are inserted at the
2840 beginning of the list. If +'index'+ is greater than or equal
2841 to the number of elements in the list, then the new elements are
2842 appended to the list.
2844 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2849 +*list* 'arg ?arg \...?'+
2851 This command returns a list comprised of all the arguments, +'arg'+. Braces
2852 and backslashes get added as necessary, so that the `lindex` command
2853 may be used on the result to re-extract the original arguments, and also
2854 so that `eval` may be used to execute the resulting list, with
2855 +'arg1'+ comprising the command's name and the other args comprising
2856 its arguments. `list` produces slightly different results than
2857 `concat`: `concat` removes one level of grouping before forming
2858 the list, while `list` works directly from the original arguments.
2859 For example, the command
2861 list a b {c d e} {f {g h}}
2865 a b {c d e} {f {g h}}
2867 while `concat` with the same arguments will return
2875 Treats +'list'+ as a list and returns a decimal string giving
2876 the number of elements in it.
2880 +*lset* 'varName ?index ..? newValue'+
2882 Sets an element in a list.
2884 The `lset` command accepts a parameter, +'varName'+, which it interprets
2885 as the name of a variable containing a Tcl list. It also accepts
2886 zero or more indices into the list. Finally, it accepts a new value
2887 for an element of varName. If no indices are presented, the command
2890 lset varName newValue
2892 In this case, newValue replaces the old value of the variable
2895 When presented with a single index, the `lset` command
2896 treats the content of the varName variable as a Tcl list. It addresses
2897 the index'th element in it (0 refers to the first element of the
2898 list). When interpreting the list, `lset` observes the same rules
2899 concerning braces and quotes and backslashes as the Tcl command
2900 interpreter; however, variable substitution and command substitution
2901 do not occur. The command constructs a new list in which the
2902 designated element is replaced with newValue. This new list is
2903 stored in the variable varName, and is also the return value from
2906 If index is negative or greater than or equal to the number of
2907 elements in $varName, then an error occurs.
2909 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'index'+.
2911 If additional index arguments are supplied, then each argument is
2912 used in turn to address an element within a sublist designated by
2913 the previous indexing operation, allowing the script to alter
2914 elements in sublists. The command,
2918 replaces element 2 of sublist 1 with +'newValue'+.
2920 The integer appearing in each index argument must be greater than
2921 or equal to zero. The integer appearing in each index argument must
2922 be strictly less than the length of the corresponding list. In other
2923 words, the `lset` command cannot change the size of a list. If an
2924 index is outside the permitted range, an error is reported.
2929 +*lmap* 'varName list body'+
2931 +*lmap* 'varList list ?varList2 list2 \...? body'+
2933 `lmap` is a "collecting" `foreach` which returns a list of its results.
2937 jim> lmap i {1 2 3 4 5} {expr $i*$i}
2939 jim> lmap a {1 2 3} b {A B C} {list $a $b}
2942 If the body invokes `continue`, no value is added for this iteration.
2943 If the body invokes `break`, the loop ends and no more values are added.
2949 Loads the dynamic extension, +'filename'+. Generally the filename should have
2950 the extension +.so+. The initialisation function for the module must be based
2951 on the name of the file. For example loading +hwaccess.so+ will invoke
2952 the initialisation function, +Jim_hwaccessInit+. Normally the `load` command
2953 should not be used directly. Instead it is invoked automatically by `package require`.
2957 +*lrange* 'list first last'+
2959 +'list'+ must be a valid Tcl list. This command will return a new
2960 list consisting of elements +'first'+ through +'last'+, inclusive.
2962 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
2964 If +'last'+ is greater than or equal to the number of elements
2965 in the list, then it is treated as if it were +end+.
2967 If +'first'+ is greater than +'last'+ then an empty string
2970 Note: +"`lrange` 'list first first'"+ does not always produce the
2971 same result as +"`lindex` 'list first'"+ (although it often does
2972 for simple fields that aren't enclosed in braces); it does, however,
2973 produce exactly the same results as +"`list` [`lindex` 'list first']"+
2978 +*lreplace* 'list first last ?element element \...?'+
2980 Returns a new list formed by replacing one or more elements of
2981 +'list'+ with the +'element'+ arguments.
2983 +'first'+ gives the index in +'list'+ of the first element
2986 If +'first'+ is less than zero then it refers to the first
2987 element of +'list'+; the element indicated by +'first'+
2988 must exist in the list.
2990 +'last'+ gives the index in +'list'+ of the last element
2991 to be replaced; it must be greater than or equal to +'first'+.
2993 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
2995 The +'element'+ arguments specify zero or more new arguments to
2996 be added to the list in place of those that were deleted.
2998 Each +'element'+ argument will become a separate element of
3001 If no +'element'+ arguments are specified, then the elements
3002 between +'first'+ and +'last'+ are simply deleted.
3006 +*lrepeat* 'number element1 ?element2 \...?'+
3008 Build a list by repeating elements +'number'+ times (which must be
3009 a positive integer).
3018 Returns the list in reverse order.
3020 jim> lreverse {1 2 3}
3025 +*lsearch* '?options? list pattern'+
3027 This command searches the elements +'list'+ to see if one of them matches +'pattern'+. If so, the
3028 command returns the index of the first matching element (unless the options -all, -inline or -bool are
3029 specified.) If not, the command returns -1. The option arguments indicates how the elements of
3030 the list are to be matched against pattern and must have one of the values below:
3032 *Note* that this command is different from Tcl in that default match type is +-exact+ rather than +-glob+.
3035 +'pattern'+ is a literal string that is compared for exact equality against each list element.
3036 This is the default.
3039 +'pattern'+ is a glob-style pattern which is matched against each list element using the same
3040 rules as the string match command.
3043 +'pattern'+ is treated as a regular expression and matched against each list element using
3044 the rules described by `regexp`.
3047 Changes the result to be the list of all matching indices (or all matching values if
3048 +-inline+ is specified as well). If indices are returned, the indices will be in numeric
3049 order. If values are returned, the order of the values will be the order of those values
3050 within the input list.
3053 The matching value is returned instead of its index (or an empty string if no value
3054 matches). If +-all+ is also specified, then the result of the command is the list of all
3055 values that matched. The +-inline+ and +-bool' options are mutually exclusive.
3058 Changes the result to '1' if a match was found, or '0' otherwise. If +-all+ is also specified,
3059 the result will be a list of '0' and '1' for each element of the list depending upon whether
3060 the corresponding element matches. The +-inline+ and +-bool+ options are mutually exclusive.
3063 This negates the sense of the match, returning the index (or value
3064 if +-inline+ is specified) of the first non-matching value in the
3065 list. If +-bool+ is also specified, the '0' will be returned if a
3066 match is found, or '1' otherwise. If +-all+ is also specified,
3067 non-matches will be returned rather than matches.
3070 Causes comparisons to be handled in a case-insensitive manner.
3074 +*lsort* ?*-index* 'listindex'? ?*-integer*|*-command* 'cmdname'? ?*-decreasing*|*-increasing*? 'list'+
3076 Sort the elements of +'list'+, returning a new list in sorted order.
3077 By default, ASCII sorting is used, with the result in increasing order.
3079 If +-integer+ is specified, numeric sorting is used.
3081 If +-command 'cmdname'+ is specified, +'cmdname'+ is treated as a command
3082 name. For each comparison, +'cmdname $value1 $value2+' is called which
3083 should compare the values and return an integer less than, equal
3084 to, or greater than zero if the +'$value1'+ is to be considered less
3085 than, equal to, or greater than +'$value2'+, respectively.
3087 If +-decreasing+ is specified, the resulting list is in the opposite
3088 order to what it would be otherwise. +-increasing+ is the default.
3090 If +-index 'listindex'+ is specified, each element of the list is treated as a list and
3091 the given index is extracted from the list for comparison. The list index may
3092 be any valid list index, such as +1+, +end+ or +end-2+.
3094 If +-index 'listindex'+ is specified, each element of the list is treated as a list and
3095 the given index is extracted from the list for comparison. The list index may
3096 be any valid list index, such as +1+, +end+ or +end-2+.
3100 +*open* 'fileName ?access?'+
3102 +*open* '|command-pipeline ?access?'+
3104 Opens a file and returns an identifier
3105 that may be used in future invocations
3106 of commands like `read`, `puts`, and `close`.
3107 +'fileName'+ gives the name of the file to open.
3109 The +'access'+ argument indicates the way in which the file is to be accessed.
3110 It may have any of the following values:
3113 Open the file for reading only; the file must already exist.
3116 Open the file for both reading and writing; the file must
3120 Open the file for writing only. Truncate it if it exists. If it doesn't
3121 exist, create a new file.
3124 Open the file for reading and writing. Truncate it if it exists.
3125 If it doesn't exist, create a new file.
3128 Open the file for writing only. The file must already exist, and the file
3129 is positioned so that new data is appended to the file.
3132 Open the file for reading and writing. If the file doesn't
3133 exist, create a new empty file. Set the initial access position
3134 to the end of the file.
3136 +'access'+ defaults to 'r'.
3138 If a file is opened for both reading and writing, then `seek`
3139 must be invoked between a read and a write, or vice versa.
3141 If the first character of +'fileName'+ is "|" then the remaining
3142 characters of +'fileName'+ are treated as a list of arguments that
3143 describe a command pipeline to invoke, in the same style as the
3144 arguments for exec. In this case, the channel identifier returned
3145 by open may be used to write to the command's input pipe or read
3146 from its output pipe, depending on the value of +'access'+. If write-only
3147 access is used (e.g. +'access'+ is 'w'), then standard output for the
3148 pipeline is directed to the current standard output unless overridden
3149 by the command. If read-only access is used (e.g. +'access'+ is r),
3150 standard input for the pipeline is taken from the current standard
3151 input unless overridden by the command.
3153 The `pid` command may be used to return the process ids of the commands
3154 forming the command pipeline.
3156 See also `socket`, `pid`, `exec`
3160 +*package provide* 'name ?version?'+
3162 Indicates that the current script provides the package named +'name'+.
3163 If no version is specified, '1.0' is used.
3165 Any script which provides a package may include this statement
3166 as the first statement, although it is not required.
3168 +*package require* 'name ?version?'*+
3170 Searches for the package with the given +'name'+ by examining each path
3171 in '$::auto_path' and trying to load '$path/$name.so' as a dynamic extension,
3172 or '$path/$name.tcl' as a script package.
3174 The first such file which is found is considered to provide the the package.
3175 (The version number is ignored).
3177 If '$name.so' exists, it is loaded with the `load` command,
3178 otherwise if '$name.tcl' exists it is loaded with the `source` command.
3180 If `load` or `source` fails, `package require` will fail immediately.
3181 No further attempt will be made to locate the file.
3189 The first form returns the process identifier of the current process.
3191 The second form accepts a handle returned by `open` and returns a list
3192 of the process ids forming the pipeline in the same form as `exec ... &`.
3193 If 'fileId' represents a regular file handle rather than a command pipeline,
3194 the empty string is returned instead.
3196 See also `open`, `exec`
3200 +*proc* 'name args ?statics? body'+
3202 The `proc` command creates a new Tcl command procedure, +'name'+.
3203 When the new command is invoked, the contents of +'body'+ will be executed.
3204 Tcl interpreter. +'args'+ specifies the formal arguments to the procedure.
3205 If specified, +'static'+, declares static variables which are bound to the
3208 See PROCEDURES for detailed information about Tcl procedures.
3210 The `proc` command returns +'name'+ (which is useful with `local`).
3212 When a procedure is invoked, the procedure's return value is the
3213 value specified in a `return` command. If the procedure doesn't
3214 execute an explicit `return`, then its return value is the value
3215 of the last command executed in the procedure's body.
3217 If an error occurs while executing the procedure body, then the
3218 procedure-as-a-whole will return that same error.
3222 +*puts* ?*-nonewline*? '?fileId? string'+
3224 +'fileId' *puts* ?*-nonewline*? 'string'+
3226 Writes the characters given by +'string'+ to the file given
3227 by +'fileId'+. +'fileId'+ must have been the return
3228 value from a previous call to `open`, or it may be
3229 +stdout+ or +stderr+ to refer to one of the standard I/O
3230 channels; it must refer to a file that was opened for
3233 In the first form, if no +'fileId'+ is specified then it defaults to +stdout+.
3234 `puts` normally outputs a newline character after +'string'+,
3235 but this feature may be suppressed by specifying the +-nonewline+
3238 Output to files is buffered internally by Tcl; the `flush`
3239 command may be used to force buffered characters to be output.
3245 Returns the path name of the current working directory.
3249 +*rand* '?min? ?max?'+
3251 Returns a random integer between +'min'+ (defaults to 0) and +'max'+
3252 (defaults to the maximum integer).
3254 If only one argument is given, it is interpreted as +'max'+.
3258 +*range* '?start? end ?step?'+
3260 Returns a list of integers starting at +'start'+ (defaults to 0)
3261 and ranging up to but not including +'end'+ in steps of +'step'+ defaults to 1).
3274 +*read* ?*-nonewline*? 'fileId'+
3276 +'fileId' *read* ?*-nonewline*?+
3278 +*read* 'fileId numBytes'+
3280 +'fileId' *read* 'numBytes'+
3283 In the first form, all of the remaining bytes are read from the file
3284 given by +'fileId'+; they are returned as the result of the command.
3285 If the +-nonewline+ switch is specified then the last
3286 character of the file is discarded if it is a newline.
3288 In the second form, the extra argument specifies how many bytes to read;
3289 exactly this many bytes will be read and returned, unless there are fewer than
3290 +'numBytes'+ bytes left in the file; in this case, all the remaining
3293 +'fileId'+ must be +stdin+ or the return value from a previous call
3294 to `open`; it must refer to a file that was opened for reading.
3298 +*regexp ?-nocase? ?-line? ?-indices? ?-start* 'offset'? *?-all? ?-inline? ?--?* 'exp string ?matchVar? ?subMatchVar subMatchVar \...?'+
3300 Determines whether the regular expression +'exp'+ matches part or
3301 all of +'string'+ and returns 1 if it does, 0 if it doesn't.
3303 See REGULAR EXPRESSIONS above for complete information on the
3304 syntax of +'exp'+ and how it is matched against +'string'+.
3306 If additional arguments are specified after +'string'+ then they
3307 are treated as the names of variables to use to return
3308 information about which part(s) of +'string'+ matched +'exp'+.
3309 +'matchVar'+ will be set to the range of +'string'+ that
3310 matched all of +'exp'+. The first +'subMatchVar'+ will contain
3311 the characters in +'string'+ that matched the leftmost parenthesized
3312 subexpression within +'exp'+, the next +'subMatchVar'+ will
3313 contain the characters that matched the next parenthesized
3314 subexpression to the right in +'exp'+, and so on.
3316 Normally, +'matchVar'+ and the each +'subMatchVar'+ are set to hold the
3317 matching characters from `string`, however see +-indices+ and
3320 If there are more values for +'subMatchVar'+ than parenthesized subexpressions
3321 within +'exp'+, or if a particular subexpression in +'exp'+ doesn't
3322 match the string (e.g. because it was in a portion of the expression
3323 that wasn't matched), then the corresponding +'subMatchVar'+ will be
3324 set to +"-1 -1"+ if +-indices+ has been specified or to an empty
3327 The following switches modify the behaviour of +'regexp'+
3330 Causes upper-case and lower-case characters to be treated as
3331 identical during the matching process.
3334 Use newline-sensitive matching. By default, newline
3335 is a completely ordinary character with no special meaning in
3336 either REs or strings. With this flag, +[^+ bracket expressions
3337 and +.+ never match newline, a +^+ anchor matches the null
3338 string after any newline in the string in addition to its normal
3339 function, and the +$+ anchor matches the null string before any
3340 newline in the string in addition to its normal function.
3343 Changes what is stored in the subMatchVars. Instead of
3344 storing the matching characters from string, each variable
3345 will contain a list of two decimal strings giving the indices
3346 in string of the first and last characters in the matching
3347 range of characters.
3349 +*-start* 'offset'+::
3350 Specifies a character index offset into the string at which to start
3351 matching the regular expression. If +-indices+ is
3352 specified, the indices will be indexed starting from the
3353 absolute beginning of the input string. +'offset'+ will be
3354 constrained to the bounds of the input string.
3357 Causes the regular expression to be matched as many times as possible
3358 in the string, returning the total number of matches found. If this
3359 is specified with match variables, they will contain information
3360 for the last match only.
3363 Causes the command to return, as a list, the data that would otherwise
3364 be placed in match variables. When using +-inline+, match variables
3365 may not be specified. If used with +-all+, the list will be concatenated
3366 at each iteration, such that a flat list is always returned. For
3367 each match iteration, the command will append the overall match
3368 data, plus one element for each subexpression in the regular
3372 Marks the end of switches. The argument following this one will be
3373 treated as +'exp'+ even if it starts with a +-+.
3377 +*regsub ?-nocase? ?-all? ?-line? ?-start* 'offset'? ?*--*? 'exp string subSpec ?varName?'+
3379 This command matches the regular expression +'exp'+ against
3380 +'string'+ using the rules described in REGULAR EXPRESSIONS
3383 If +'varName'+ is specified, the commands stores +'string'+ to +'varName'+
3384 with the substitutions detailed below, and returns the number of
3385 substitutions made (normally 1 unless +-all+ is specified).
3386 This is 0 if there were no matches.
3388 If +'varName'+ is not specified, the substituted string will be returned
3391 When copying +'string'+, the portion of +'string'+ that
3392 matched +'exp'+ is replaced with +'subSpec'+.
3393 If +'subSpec'+ contains a +&+ or +{backslash}0+, then it is replaced
3394 in the substitution with the portion of +'string'+ that
3397 If +'subSpec'+ contains a +{backslash}n+, where +'n'+ is a digit
3398 between 1 and 9, then it is replaced in the substitution with
3399 the portion of +'string'+ that matched the +''+n+''+-th
3400 parenthesized subexpression of +'exp'+.
3401 Additional backslashes may be used in +'subSpec'+ to prevent special
3402 interpretation of +&+ or +{backslash}0+ or +{backslash}n+ or
3405 The use of backslashes in +'subSpec'+ tends to interact badly
3406 with the Tcl parser's use of backslashes, so it's generally
3407 safest to enclose +'subSpec'+ in braces if it includes
3410 The following switches modify the behaviour of +'regsub'+
3413 Upper-case characters in +'string'+ are converted to lower-case
3414 before matching against +'exp'+; however, substitutions
3415 specified by +'subSpec'+ use the original unconverted form
3419 All ranges in +'string'+ that match +'exp'+ are found and substitution
3420 is performed for each of these ranges, rather than only the
3421 first. The +&+ and +{backslash}n+ sequences are handled for
3422 each substitution using the information from the corresponding
3426 Use newline-sensitive matching. By default, newline
3427 is a completely ordinary character with no special meaning in
3428 either REs or strings. With this flag, +[^+ bracket expressions
3429 and +.+ never match newline, a +^+ anchor matches the null
3430 string after any newline in the string in addition to its normal
3431 function, and the +$+ anchor matches the null string before any
3432 newline in the string in addition to its normal function.
3434 +*-start* 'offset'+::
3435 Specifies a character index offset into the string at which to
3436 start matching the regular expression. +'offset'+ will be
3437 constrained to the bounds of the input string.
3440 Marks the end of switches. The argument following this one will be
3441 treated as +'exp'+ even if it starts with a +-+.
3445 +*ref* 'string tag ?finalizer?'+
3447 Create a new reference containing +'string'+ of type +'tag'+.
3448 If +'finalizer'+ is specified, it is a command which will be invoked
3449 when the a garbage collection cycle runs and this reference is
3450 no longer accessible.
3452 The finalizer is invoked as:
3454 +finalizer 'reference string'+
3456 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
3460 +*rename* 'oldName newName'+
3462 Rename the command that used to be called +'oldName'+ so that it
3463 is now called +'newName'+. If +'newName'+ is an empty string
3464 (e.g. {}) then +'oldName'+ is deleted. The `rename` command
3465 returns an empty string as result.
3469 +*return* ?*-code* 'code'? ?*-errorinfo* 'stacktrace'? ?*-errorcode* 'errorcode'? ?*-level* 'n'? ?'value'?+
3471 Return immediately from the current procedure (or top-level command
3472 or `source` command), with +'value'+ as the return value. If +'value'+
3473 is not specified, an empty string will be returned as result.
3475 If +-code+ is specified (as either a number or ok, error, break,
3476 continue, signal, return or exit), this code will be used instead
3477 of +JIM_OK+. This is generally useful when implementing flow of control
3480 If +-level+ is specified and greater than 1, it has the effect of delaying
3481 the new return code from +-code+. This is useful when rethrowing an error
3482 from `catch`. See the implementation of try/catch in tclcompat.tcl for
3483 an example of how this is done.
3485 Note: The following options are only used when +-code+ is JIM_ERR.
3487 If +-errorinfo+ is specified (as returned from `info stacktrace`)
3488 it is used to initialize the stacktrace.
3490 If +-errorcode+ is specified, it is used to set the global variable $::errorCode.
3494 +*scan* 'string format varName1 ?varName2 \...?'+
3496 This command parses fields from an input string in the same fashion
3497 as the C 'sscanf' procedure. +'string'+ gives the input to be parsed
3498 and +'format'+ indicates how to parse it, using '%' fields as in
3499 'sscanf'. All of the 'sscanf' options are valid; see the 'sscanf'
3500 man page for details. Each +'varName'+ gives the name of a variable;
3501 when a field is scanned from +'string'+, the result is converted back
3502 into a string and assigned to the corresponding +'varName'+. The
3503 only unusual conversion is for '%c'. For '%c' conversions a single
3504 character value is converted to a decimal string, which is then
3505 assigned to the corresponding +'varName'+; no field width may be
3506 specified for this conversion.
3510 +*seek* 'fileId offset ?origin?'+
3512 +'fileId' *seek* 'offset ?origin?'+
3514 Change the current access position for +'fileId'+.
3515 The +'offset'+ and +'origin'+ arguments specify the position at
3516 which the next read or write will occur for +'fileId'+.
3517 +'offset'+ must be a number (which may be negative) and +'origin'+
3518 must be one of the following:
3521 The new access position will be +'offset'+ bytes from the start
3525 The new access position will be +'offset'+ bytes from the current
3526 access position; a negative +'offset'+ moves the access position
3527 backwards in the file.
3530 The new access position will be +'offset'+ bytes from the end of
3531 the file. A negative +'offset'+ places the access position before
3532 the end-of-file, and a positive +'offset'+ places the access position
3533 after the end-of-file.
3535 The +'origin'+ argument defaults to +start+.
3537 +'fileId'+ must have been the return value from a previous call to
3538 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
3539 of the standard I/O channels.
3541 This command returns an empty string.
3545 +*set* 'varName ?value?'+
3547 Returns the value of variable +'varName'+.
3549 If +'value'+ is specified, then set the value of +'varName'+ to +'value'+,
3550 creating a new variable if one doesn't already exist, and return
3553 If +'varName'+ contains an open parenthesis and ends with a
3554 close parenthesis, then it refers to an array element: the characters
3555 before the open parenthesis are the name of the array, and the characters
3556 between the parentheses are the index within the array.
3557 Otherwise +'varName'+ refers to a scalar variable.
3559 If no procedure is active, then +'varName'+ refers to a global
3562 If a procedure is active, then +'varName'+ refers to a parameter
3563 or local variable of the procedure, unless the +'global'+ command
3564 has been invoked to declare +'varName'+ to be global.
3566 The +::+ prefix may also be used to explicitly reference a variable
3567 in the global scope.
3571 +*setref* 'reference string'+
3573 Store a new string in +'reference'+, replacing the existing string.
3574 The reference must be a valid reference create with the `ref`
3577 See GARBAGE COLLECTION, REFERENCES, LAMBDA for more detail.
3581 Command for signal handling.
3583 See `kill` for the different forms which may be used to specify signals.
3585 Commands which return a list of signal names do so using the canonical form:
3588 +*signal handle* ?'signals \...'?+::
3589 If no signals are given, returns a list of all signals which are currently
3591 If signals are specified, these are added to the list of signals currently
3594 +*signal ignore* ?'signals \...'?+::
3595 If no signals are given, returns a lists all signals which are currently
3597 If signals are specified, these are added to the list of signals
3598 currently being ignored. These signals are still delivered, but
3599 are not considered by `catch -signal` or `try -signal`. Use
3600 `signal check` to determine which signals have occurred but
3603 +*signal default* ?'signals \...'?+::
3604 If no signals are given, returns a lists all signals which are currently have
3605 the default behaviour.
3606 If signals are specified, these are added to the list of signals which have
3607 the default behaviour.
3609 +*signal check ?-clear?* ?'signals \...'?+::
3610 Returns a list of signals which have been delivered to the process
3611 but are 'ignored'. If signals are specified, only that set of signals will
3612 be checked, otherwise all signals will be checked.
3613 If +-clear+ is specified, any signals returned are removed and will not be
3614 returned by subsequent calls to `signal check` unless delivered again.
3616 +*signal throw* ?'signal'?+::
3617 Raises the given signal, which defaults to +SIGINT+ if not specified.
3618 The behaviour is identical to:
3622 Note that `signal handle` and `signal ignore` represent two forms of signal
3623 handling. `signal handle` is used in conjunction with `catch -signal` or `try -signal`
3624 to immediately abort execution when the signal is delivered. Alternatively, `signal ignore`
3625 is used in conjunction with `signal check` to handle signal synchronously. Consider the
3628 Prevent a processing from taking too long
3630 signal handle SIGALRM
3633 .. possibly long running process ..
3636 puts stderr "Process took too long"
3639 Handle SIGHUP to reconfigure:
3641 signal ignore SIGHUP
3643 ... handle configuration/reconfiguration ...
3644 while {[signal check -clear SIGHUP] eq ""} {
3645 ... do processing ..
3647 # Received SIGHUP, so reconfigure
3654 Pauses for the given number of seconds, which may be a floating
3655 point value less than one to sleep for less than a second, or an
3656 integer to sleep for one or more seconds.
3660 +*source* 'fileName'+
3662 Read file +'fileName'+ and pass the contents to the Tcl interpreter
3663 as a sequence of commands to execute in the normal fashion. The return
3664 value of `source` is the return value of the last command executed
3665 from the file. If an error occurs in executing the contents of the
3666 file, then the `source` command will return that error.
3668 If a `return` command is invoked from within the file, the remainder of
3669 the file will be skipped and the `source` command will return
3670 normally with the result from the `return` command.
3674 +*split* 'string ?splitChars?'+
3676 Returns a list created by splitting +'string'+ at each character
3677 that is in the +'splitChars'+ argument.
3679 Each element of the result list will consist of the
3680 characters from +'string'+ between instances of the
3681 characters in +'splitChars'+.
3683 Empty list elements will be generated if +'string'+ contains
3684 adjacent characters in +'splitChars'+, or if the first or last
3685 character of +'string'+ is in +'splitChars'+.
3687 If +'splitChars'+ is an empty string then each character of
3688 +'string'+ becomes a separate element of the result list.
3690 +'splitChars'+ defaults to the standard white-space characters.
3693 split "comp.unix.misc" .
3695 returns +'"comp unix misc"'+ and
3697 split "Hello world" {}
3699 returns +'"H e l l o { } w o r l d"'+.
3704 +*stackdump* 'stacktrace'+
3706 Creates a human readable representation of a stack trace.
3713 Returns a live stack trace as a list of +proc file line proc file line \...+.
3714 Iteratively uses `info frame` to create the stack trace. This stack trace is in the
3715 same form as produced by `catch` and `info stacktrace`
3717 See also `stackdump`.
3722 +*string* 'option arg ?arg \...?'+
3724 Perform one of several string operations, depending on +'option'+.
3725 The legal options (which may be abbreviated) are:
3727 +*string bytelength* 'string'+::
3728 Returns the length of the string in bytes. This will return
3729 the same value as `string length` if UTF-8 support is not enabled,
3730 or if the string is composed entirely of ASCII characters.
3731 See UTF-8 AND UNICODE.
3733 +*string byterange* 'string first last'+::
3734 Like `string range` except works on bytes rather than characters.
3735 These commands are identical if UTF-8 support is not enabled.
3737 +*string compare ?-nocase?* 'string1 string2'+::
3738 Perform a character-by-character comparison of strings +'string1'+ and
3739 +'string2'+ in the same way as the C 'strcmp' procedure. Return
3740 -1, 0, or 1, depending on whether +'string1'+ is lexicographically
3741 less than, equal to, or greater than +'string2'+.
3742 Performs a case-insensitive comparison if +-nocase+ is specified.
3744 +*string equal ?-nocase?* 'string1 string2'+::
3745 Returns 1 if the strings are equal, or 0 otherwise.
3746 Performs a case-insensitive comparison if +-nocase+ is specified.
3748 +*string first* 'string1 string2 ?firstIndex?'+::
3749 Search +'string2'+ for a sequence of characters that exactly match
3750 the characters in +'string1'+. If found, return the index of the
3751 first character in the first such match within +'string2'+. If not
3752 found, return -1. If +'firstIndex'+ is specified, matching will start
3753 from +'firstIndex'+ of +'string1'+.
3755 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'firstIndex'+.
3757 +*string index* 'string charIndex'+::
3758 Returns the +'charIndex'+'th character of the +'string'+
3759 argument. A +'charIndex'+ of 0 corresponds to the first
3760 character of the string.
3761 If +'charIndex'+ is less than 0 or greater than
3762 or equal to the length of the string then an empty string is
3765 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'charIndex'+.
3767 +*string is* 'class' ?*-strict*? 'string'+::
3768 Returns 1 if +'string'+ is a valid member of the specified character
3769 class, otherwise returns 0. If +-strict+ is specified, then an
3770 empty string returns 0, otherwise an empty string will return 1
3771 on any class. The following character classes are recognized
3772 (the class name can be abbreviated):
3774 +alnum+;; Any alphabet or digit character.
3775 +alpha+;; Any alphabet character.
3776 +ascii+;; Any character with a value less than 128 (those that are in the 7-bit ascii range).
3777 +control+;; Any control character.
3778 +digit+;; Any digit character.
3779 +double+;; Any of the valid forms for a double in Tcl, with optional surrounding whitespace.
3780 In case of under/overflow in the value, 0 is returned.
3781 +graph+;; Any printing character, except space.
3782 +integer+;; Any of the valid string formats for an integer value in Tcl, with optional surrounding whitespace.
3783 +lower+;; Any lower case alphabet character.
3784 +print+;; Any printing character, including space.
3785 +punct+;; Any punctuation character.
3786 +space+;; Any space character.
3787 +upper+;; Any upper case alphabet character.
3788 +xdigit+;; Any hexadecimal digit character ([0-9A-Fa-f]).
3790 Note that string classification does +'not'+ respect UTF-8. See UTF-8 AND UNICODE
3792 +*string last* 'string1 string2 ?lastIndex?'+::
3793 Search +'string2'+ for a sequence of characters that exactly match
3794 the characters in +'string1'+. If found, return the index of the
3795 first character in the last such match within +'string2'+. If there
3796 is no match, then return -1. If +'lastIndex'+ is specified, only characters
3797 up to +'lastIndex'+ of +'string2'+ will be considered in the match.
3799 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'lastIndex'+.
3801 +*string length* 'string'+::
3802 Returns a decimal string giving the number of characters in +'string'+.
3803 If UTF-8 support is enabled, this may be different than the number of bytes.
3804 See UTF-8 AND UNICODE
3806 +*string map ?-nocase?* 'mapping string'+::
3807 Replaces substrings in +'string'+ based on the key-value pairs in
3808 +'mapping'+, which is a list of +key value key value \...+ as in the form
3809 returned by `array get`. Each instance of a key in the string will be
3810 replaced with its corresponding value. If +-nocase+ is specified, then
3811 matching is done without regard to case differences. Both key and value may
3812 be multiple characters. Replacement is done in an ordered manner, so the
3813 key appearing first in the list will be checked first, and so on. +'string'+ is
3814 only iterated over once, so earlier key replacements will have no affect for
3815 later key matches. For example,
3817 string map {abc 1 ab 2 a 3 1 0} 1abcaababcabababc
3820 will return the string +01321221+.
3822 Note that if an earlier key is a prefix of a later one, it will completely mask the later
3823 one. So if the previous example is reordered like this,
3825 string map {1 0 ab 2 a 3 abc 1} 1abcaababcabababc
3828 it will return the string +02c322c222c+.
3830 +*string match ?-nocase?* 'pattern string'+::
3831 See if +'pattern'+ matches +'string'+; return 1 if it does, 0
3832 if it doesn't. Matching is done in a fashion similar to that
3833 used by the C-shell. For the two strings to match, their contents
3834 must be identical except that the following special sequences
3835 may appear in +'pattern'+:
3838 Matches any sequence of characters in +'string'+,
3839 including a null string.
3842 Matches any single character in +'string'+.
3845 Matches any character in the set given by +'chars'+.
3846 If a sequence of the form +'x-y'+ appears in +'chars'+,
3847 then any character between +'x'+ and +'y'+, inclusive,
3851 Matches the single character +'x'+. This provides a way of
3852 avoiding the special interpretation of the characters +{backslash}*?[]+
3855 Performs a case-insensitive comparison if +-nocase+ is specified.
3857 +*string range* 'string first last'+::
3858 Returns a range of consecutive characters from +'string'+, starting
3859 with the character whose index is +'first'+ and ending with the
3860 character whose index is +'last'+. An index of 0 refers to the
3861 first character of the string.
3863 See STRING AND LIST INDEX SPECIFICATIONS for all allowed forms for +'first'+ and +'last'+.
3865 If +'first'+ is less than zero then it is treated as if it were zero, and
3866 if +'last'+ is greater than or equal to the length of the string then
3867 it is treated as if it were +end+. If +'first'+ is greater than
3868 +'last'+ then an empty string is returned.
3870 +*string repeat* 'string count'+::
3871 Returns a new string consisting of +'string'+ repeated +'count'+ times.
3873 +*string reverse* 'string'+::
3874 Returns a string that is the same length as +'string'+ but
3875 with its characters in the reverse order.
3877 +*string tolower* 'string'+::
3878 Returns a value equal to +'string'+ except that all upper case
3879 letters have been converted to lower case.
3881 +*string toupper* 'string'+::
3882 Returns a value equal to +'string'+ except that all lower case
3883 letters have been converted to upper case.
3885 +*string trim* 'string ?chars?'+::
3886 Returns a value equal to +'string'+ except that any leading
3887 or trailing characters from the set given by +'chars'+ are
3889 If +'chars'+ is not specified then white space is removed
3890 (spaces, tabs, newlines, and carriage returns).
3892 +*string trimleft* 'string ?chars?'+::
3893 Returns a value equal to +'string'+ except that any
3894 leading characters from the set given by +'chars'+ are
3896 If +'chars'+ is not specified then white space is removed
3897 (spaces, tabs, newlines, and carriage returns).
3899 +*string trimright* 'string ?chars?'+::
3900 Returns a value equal to +'string'+ except that any
3901 trailing characters from the set given by +'chars'+ are
3903 If +'chars'+ is not specified then white space is removed
3904 (spaces, tabs, newlines, and carriage returns).
3905 Null characters are always removed.
3909 +*subst ?-nobackslashes? ?-nocommands? ?-novariables?* 'string'+
3911 This command performs variable substitutions, command substitutions,
3912 and backslash substitutions on its string argument and returns the
3913 fully-substituted result. The substitutions are performed in exactly
3914 the same way as for Tcl commands. As a result, the string argument
3915 is actually substituted twice, once by the Tcl parser in the usual
3916 fashion for Tcl commands, and again by the subst command.
3918 If any of the +-nobackslashes+, +-nocommands+, or +-novariables+ are
3919 specified, then the corresponding substitutions are not performed.
3920 For example, if +-nocommands+ is specified, no command substitution
3921 is performed: open and close brackets are treated as ordinary
3922 characters with no special interpretation.
3924 *Note*: when it performs its substitutions, subst does not give any
3925 special treatment to double quotes or curly braces. For example,
3926 the following script returns +xyz \{44\}+, not +xyz \{$a\}+.
3934 +*switch* '?options? string pattern body ?pattern body \...?'+
3936 +*switch* '?options? string {pattern body ?pattern body \...?}'+
3938 The `switch` command matches its string argument against each of
3939 the pattern arguments in order. As soon as it finds a pattern that
3940 matches string it evaluates the following body and returns the
3941 result of that evaluation. If the last pattern argument is default
3942 then it matches anything. If no pattern argument matches string and
3943 no default is given, then the `switch` command returns an empty string.
3944 If the initial arguments to switch start with - then they are treated
3945 as options. The following options are currently supported:
3948 Use exact matching when comparing string to a
3949 pattern. This is the default.
3952 When matching string to the patterns, use glob-style
3953 matching (i.e. the same as implemented by the string
3957 When matching string to the patterns, use regular
3958 expression matching (i.e. the same as implemented
3959 by the regexp command).
3961 +-command 'commandname'+::
3962 When matching string to the patterns, use the given command, which
3963 must be a single word. The command is invoked as
3964 'commandname pattern string', or 'commandname -nocase pattern string'
3965 and must return 1 if matched, or 0 if not.
3968 Marks the end of options. The argument following
3969 this one will be treated as string even if it starts
3972 Two syntaxes are provided for the pattern and body arguments. The
3973 first uses a separate argument for each of the patterns and commands;
3974 this form is convenient if substitutions are desired on some of the
3975 patterns or commands. The second form places all of the patterns
3976 and commands together into a single argument; the argument must
3977 have proper list structure, with the elements of the list being the
3978 patterns and commands. The second form makes it easy to construct
3979 multi-line `switch` commands, since the braces around the whole list
3980 make it unnecessary to include a backslash at the end of each line.
3981 Since the pattern arguments are in braces in the second form, no
3982 command or variable substitutions are performed on them; this makes
3983 the behaviour of the second form different than the first form in
3986 If a body is specified as +-+ it means that the body for the next
3987 pattern should also be used as the body for this pattern (if the
3988 next pattern also has a body of +-+ then the body after that is
3989 used, and so on). This feature makes it possible to share a single
3990 body among several patterns.
3992 Below are some examples of `switch` commands:
3994 switch abc a - b {format 1} abc {format 2} default {format 3}
3998 switch -regexp aaab {
4018 +*tailcall* 'cmd ?arg\...?'+
4020 The `tailcall` command provides an optimised way of invoking a command whilst replacing
4021 the current call frame. This is similar to 'exec' in Bourne Shell.
4023 The following are identical except the first immediately replaces the current call frame.
4027 return [uplevel 1 a b c]
4029 `tailcall` is useful for a dispatch mechanism:
4032 tailcall sub_$cmd {*}$args
4043 Returns a decimal string giving the current access position in
4046 +'fileId'+ must have been the return value from a previous call to
4047 `open`, or it may be +stdin+, +stdout+, or +stderr+ to refer to one
4048 of the standard I/O channels.
4052 +*throw* 'code ?msg?'+
4054 This command throws an exception (return) code along with an optional message.
4055 This command is mostly for convenient usage with `try`.
4057 The command +throw break+ is equivalent to +break+.
4058 The command +throw 20 message+ can be caught with an +on 20 \...+ clause to `try`.
4062 +*time* 'command ?count?'+
4064 This command will call the Tcl interpreter +'count'+
4065 times to execute +'command'+ (or once if +'count'+ isn't
4066 specified). It will then return a string of the form
4068 503 microseconds per iteration
4070 which indicates the average amount of time required per iteration,
4073 Time is measured in elapsed time, not CPU time.
4077 +*try* '?catchopts? tryscript' ?*on* 'returncodes {?resultvar? ?optsvar?} handlerscript \...'? ?*finally* 'finalscript'?+
4079 The `try` command is provided as a convenience for exception handling.
4081 This interpeter first evaluates +'tryscript'+ under the effect of the catch
4082 options +'catchopts'+ (e.g. +-signal -noexit --+, see `catch`).
4084 It then evaluates the script for the first matching 'on' handler
4085 (there many be zero or more) based on the return code from the `try`
4086 section. For example a normal +JIM_ERR+ error will be matched by
4087 an 'on error' handler.
4089 Finally, any +'finalscript'+ is evaluated.
4091 The result of this command is the result of +'tryscript'+, except in the
4092 case where an exception occurs in a matching 'on' handler script or the 'finally' script,
4093 in which case the result is this new exception.
4095 The specified +'returncodes'+ is a list of return codes either as names ('ok', 'error', 'break', etc.)
4098 If +'resultvar'+ and +'optsvar'+ are specified, they are set as for `catch` before evaluating
4099 the matching handler.
4106 } on {continue break} {} {
4107 error "Unexpected break/continue"
4108 } on error {msg opts} {
4109 puts "Dealing with error"
4110 return {*}$opts $msg
4112 puts "Got signal: $sig"
4117 If break, continue or error are raised, they are dealt with by the matching
4120 In any case, the file will be closed via the 'finally' clause.
4122 See also `throw`, `catch`, `return`, `error`.
4126 +*unknown* 'cmdName ?arg arg ...?'+
4128 This command doesn't actually exist as part of Tcl, but Tcl will
4129 invoke it if it does exist.
4131 If the Tcl interpreter encounters a command name for which there
4132 is not a defined command, then Tcl checks for the existence of
4133 a command named `unknown`.
4135 If there is no such command, then the interpreter returns an
4138 If the `unknown` command exists, then it is invoked with
4139 arguments consisting of the fully-substituted name and arguments
4140 for the original non-existent command.
4142 The `unknown` command typically does things like searching
4143 through library directories for a command procedure with the name
4144 +'cmdName'+, or expanding abbreviated command names to full-length,
4145 or automatically executing unknown commands as UNIX sub-processes.
4147 In some cases (such as expanding abbreviations) `unknown` will
4148 change the original command slightly and then (re-)execute it.
4149 The result of the `unknown` command is used as the result for
4150 the original non-existent command.
4154 +*unset ?-nocomplain? ?--?* '?name name ...?'+
4157 Each +'name'+ is a variable name, specified in any of the
4158 ways acceptable to the `set` command.
4160 If a +'name'+ refers to an element of an array, then that
4161 element is removed without affecting the rest of the array.
4163 If a +'name'+ consists of an array name with no parenthesized
4164 index, then the entire array is deleted.
4166 The `unset` command returns an empty string as result.
4168 An error occurs if any of the variables doesn't exist, unless '-nocomplain'
4169 is specified. The '--' argument may be specified to stop option processing
4170 in case the variable name may be '-nocomplain'.
4174 +*upcall* 'command ?args ...?'+
4176 May be used from within a proc defined as `local` `proc` in order to call
4177 the previous, hidden version of the same command.
4179 If there is no previous definition of the command, an error is returned.
4183 +*uplevel* '?level? command ?command ...?'+
4185 All of the +'command'+ arguments are concatenated as if they had
4186 been passed to `concat`; the result is then evaluated in the
4187 variable context indicated by +'level'+. `uplevel` returns
4188 the result of that evaluation. If +'level'+ is an integer, then
4189 it gives a distance (up the procedure calling stack) to move before
4190 executing the command. If +'level'+ consists of +\#+ followed by
4191 a number then the number gives an absolute level number. If +'level'+
4192 is omitted then it defaults to +1+. +'level'+ cannot be
4193 defaulted if the first +'command'+ argument starts with a digit or +#+.
4195 For example, suppose that procedure 'a' was invoked
4196 from top-level, and that it called 'b', and that 'b' called 'c'.
4197 Suppose that 'c' invokes the `uplevel` command. If +'level'+
4198 is +1+ or +#2+ or omitted, then the command will be executed
4199 in the variable context of 'b'. If +'level'+ is +2+ or +#1+
4200 then the command will be executed in the variable context of 'a'.
4202 If +'level'+ is '3' or +#0+ then the command will be executed
4203 at top-level (only global variables will be visible).
4204 The `uplevel` command causes the invoking procedure to disappear
4205 from the procedure calling stack while the command is being executed.
4206 In the above example, suppose 'c' invokes the command
4208 uplevel 1 {set x 43; d}
4210 where 'd' is another Tcl procedure. The `set` command will
4211 modify the variable 'x' in 'b's context, and 'd' will execute
4212 at level 3, as if called from 'b'. If it in turn executes
4217 then the `set` command will modify the same variable 'x' in 'b's
4218 context: the procedure 'c' does not appear to be on the call stack
4219 when 'd' is executing. The command `info level` may
4220 be used to obtain the level of the current procedure.
4222 `uplevel` makes it possible to implement new control
4223 constructs as Tcl procedures (for example, `uplevel` could
4224 be used to implement the `while` construct as a Tcl procedure).
4228 +*upvar* '?level? otherVar myVar ?otherVar myVar ...?'+
4230 This command arranges for one or more local variables in the current
4231 procedure to refer to variables in an enclosing procedure call or
4232 to global variables.
4234 +'level'+ may have any of the forms permitted for the `uplevel`
4235 command, and may be omitted if the first letter of the first +'otherVar'+
4236 isn't +#+ or a digit (it defaults to '1').
4238 For each +'otherVar'+ argument, `upvar` makes the variable
4239 by that name in the procedure frame given by +'level'+ (or at
4240 global level, if +'level'+ is +#0+) accessible
4241 in the current procedure by the name given in the corresponding
4244 The variable named by +'otherVar'+ need not exist at the time of the
4245 call; it will be created the first time +'myVar'+ is referenced, just like
4246 an ordinary variable.
4248 `upvar` may only be invoked from within procedures.
4250 `upvar` returns an empty string.
4252 The `upvar` command simplifies the implementation of call-by-name
4253 procedure calling and also makes it easier to build new control constructs
4255 For example, consider the following procedure:
4262 'add2' is invoked with an argument giving the name of a variable,
4263 and it adds two to the value of that variable.
4264 Although 'add2' could have been implemented using `uplevel`
4265 instead of `upvar`, `upvar` makes it simpler for 'add2'
4266 to access the variable in the caller's procedure frame.
4270 +*while* 'test body'+
4272 The +'while'+ command evaluates +'test'+ as an expression
4273 (in the same way that `expr` evaluates its argument).
4274 The value of the expression must be numeric; if it is non-zero
4275 then +'body'+ is executed by passing it to the Tcl interpreter.
4277 Once +'body'+ has been executed then +'test'+ is evaluated
4278 again, and the process repeats until eventually +'test'+
4279 evaluates to a zero numeric value. `continue`
4280 commands may be executed inside +'body'+ to terminate the current
4281 iteration of the loop, and `break`
4282 commands may be executed inside +'body'+ to cause immediate
4283 termination of the `while` command.
4285 The `while` command always returns an empty string.
4290 The following extensions may or may not be available depending upon
4291 what options were selected when Jim Tcl was built.
4294 posix: os.fork, os.wait, os.gethostname, os.getids, os.uptime
4295 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4297 Invokes 'fork(2)' and returns the result.
4299 +*os.wait -nohang* 'pid'+::
4300 Invokes waitpid(2), with WNOHANG if +-nohang+ is specified.
4301 Returns a list of 3 elements.
4303 {0 none 0} if -nohang is specified, and the process is still alive.
4305 {-1 error <error-description>} if the process does not exist or has already been waited for.
4307 {<pid> exit <exit-status>} if the process exited normally.
4309 {<pid> signal <signal-number>} if the process terminated on a signal.
4311 {<pid> other 0} otherwise (core dump, stopped, continued, etc.)
4313 +*os.gethostname*+::
4314 Invokes 'gethostname(3)' and returns the result.
4317 Returns the various user/group ids for the current process.
4320 uid 1000 euid 1000 gid 100 egid 100
4323 Returns the number of seconds since system boot. See description of 'uptime' in 'sysinfo(2)'.
4325 ANSI I/O (aio) and EVENTLOOP API
4326 --------------------------------
4327 Jim provides an alternative object-based API for I/O.
4329 See `open` and `socket` for commands which return an I/O handle.
4333 +$handle *read ?-nonewline?* '?len?'+::
4334 Read and return bytes from the stream. To eof if no len.
4336 +$handle *gets* '?var?'+::
4337 Read one line and return it or store it in the var
4339 +$handle *puts ?-nonewline?* 'str'+::
4340 Write the string, with newline unless -nonewline
4342 +$handle *copyto* 'tofd ?size?'+::
4343 Copy bytes to the file descriptor +'tofd'+. If +'size'+ is specified, at most
4344 that many bytes will be copied. Otherwise copying continues until the end
4345 of the input file. Returns the number of bytes actually copied.
4350 +$handle *filename*+::
4351 Returns the original filename associated with the handle.
4352 Handles returned by `socket` give the socket type instead of a filename.
4355 Returns 1 if stream is at eof
4360 +$handle *seek* 'offset' *?start|current|end?*+::
4361 Seeks in the stream (default 'current')
4364 Returns the current seek position
4366 +$handle *filename*+::
4367 Returns the original filename used when opening the file.
4368 If the handle was returned from `socket`, the type of the
4369 handle is returned instead.
4371 +$handle *ndelay ?0|1?*+::
4372 Set O_NDELAY (if arg). Returns current/new setting.
4373 Note that in general ANSI I/O interacts badly with non-blocking I/O.
4376 +$handle *buffering none|line|full*+::
4377 Sets the buffering mode of the stream.
4379 +$handle *accept*+::
4380 Server socket only: Accept a connection and return stream
4382 +$handle *sendto* 'str ?hostname:?port'+::
4383 Sends the string, +'str'+, to the given address via the socket using sendto(2).
4384 This is intended for udp sockets and may give an error or behave in unintended
4385 ways for other handle types.
4386 Returns the number of bytes written.
4388 +$handle *recvfrom* 'maxlen ?addrvar?'+::
4389 Receives a message from the handle via recvfrom(2) and returns it.
4390 At most +'maxlen'+ bytes are read.
4391 If +'addrvar'+ is specified, the sending address of the message is stored in
4392 the named variable in the form 'addr:port'. See `socket` for details.
4396 +*fconfigure* 'handle' *?-blocking 0|1? ?-buffering noneline|full? ?-translation* 'mode'?+::
4397 For compatibility with Tcl, a limited form of the `fconfigure`
4398 command is supported.
4399 * `fconfigure ... -blocking` maps to `aio ndelay`
4400 * `fconfigure ... -buffering` maps to `aio buffering`
4401 * `fconfigure ... -translation` is accepted but ignored
4404 eventloop: after, vwait, update
4405 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4407 The following commands allow a script to be invoked when the given condition occurs.
4408 If no script is given, returns the current script. If the given script is the empty, the
4411 +$handle *readable* '?readable-script?'+::
4412 Sets or returns the script for when the socket is readable.
4414 +$handle *writable* '?writable-script?'+::
4415 Sets or returns the script for when the socket is writable.
4417 +$handle *onexception* '?exception-script?'+::
4418 Sets or returns the script for when when oob data received.
4420 For compatibility with 'Tcl', these may be prefixed with `fileevent`. e.g.
4423 +fileevent $handle *readable* '\...'+
4425 Time-based execution is also available via the eventloop API.
4428 Sleeps for the given number of milliseconds. No events are
4429 processed during this time.
4431 +*after* 'ms'|*idle* script ?script \...?'+::
4432 The scripts are concatenated and executed after the given
4433 number of milliseconds have elapsed. If 'idle' is specified,
4434 the script will run the next time the event loop is processed
4435 with `vwait` or `update`. The script is only run once and
4436 then removed. Returns an event id.
4438 +*after cancel* 'id|command'+::
4439 Cancels an `after` event with the given event id or matching
4440 command (script). Returns the number of milliseconds
4441 remaining until the event would have fired. Returns the
4442 empty string if no matching event is found.
4444 +*after info* '?id?'+::
4445 If +'id'+ is not given, returns a list of current `after`
4446 events. If +'id'+ is given, returns a list containing the
4447 associated script and either 'timer' or 'idle' to indicated
4448 the type of the event. An error occurs if +'id'+ does not
4451 +*vwait* 'variable'+::
4452 A call to `vwait` is enters the eventloop. `vwait` processes
4453 events until the named (global) variable changes or all
4454 event handlers are removed. The variable need not exist
4455 beforehand. If there are no event handlers defined, `vwait`
4456 returns immediately.
4458 +*update ?idletasks?*+::
4459 A call to `update` enters the eventloop to process expired events, but
4460 no new events. If 'idletasks' is specified, only expired time events are handled,
4462 Returns once handlers have been run for all expired events.
4464 Scripts are executed at the global scope. If an error occurs during a handler script,
4465 an attempt is made to call (the user-defined command) `bgerror` with the details of the error.
4466 If the `bgerror` commands does not exist, it is printed to stderr instead.
4468 If a file event handler script generates an error, the handler is automatically removed
4469 to prevent infinite errors. (A time event handler is always removed after execution).
4471 +*bgerror* 'error'+::
4472 Called when an event handler script generates an error.
4476 Various socket types may be created.
4478 +*socket unix* 'path'+::
4479 A unix domain socket client.
4481 +*socket unix.server* 'path'+::
4482 A unix domain socket server.
4484 +*socket ?-ipv6? stream* 'addr:port'+::
4485 A TCP socket client.
4487 +*socket ?-ipv6? stream.server* '?addr:?port'+::
4488 A TCP socket server (+'addr'+ defaults to +0.0.0.0+ for IPv4 or +[::]+ for IPv6).
4490 +*socket ?-ipv6? dgram* ?'addr:port'?+::
4491 A UDP socket client. If the address is not specified,
4492 the client socket will be unbound and 'sendto' must be used
4493 to indicated the destination.
4495 +*socket ?-ipv6? dgram.server* 'addr:port'+::
4496 A UDP socket server.
4499 A pipe. Note that unlike all other socket types, this command returns
4500 a list of two channels: {read write}
4502 This command creates a socket connected (client) or bound (server) to the given
4505 The returned value is channel and may generally be used with the various file I/O
4506 commands (gets, puts, read, etc.), either as object-based syntax or Tcl-compatible syntax.
4508 set f [socket stream www.google.com:80]
4510 $f puts -nonewline "GET / HTTP/1.0\r\n\r\n"
4515 Server sockets, however support only 'accept', which is most useful in conjunction with
4518 set f [socket stream.server 80]
4520 set client [$f accept]
4523 $client puts -nonewline "HTTP/1.1 404 Not found\r\n"
4528 The address, +'addr'+, can be given in one of the following forms:
4530 1. For IPv4 socket types, an IPv4 address such as 192.168.1.1
4531 2. For IPv6 socket types, an IPv6 address such as [fe80::1234] or [::]
4534 Note that on many systems, listening on an IPv6 address such as [::] will
4535 also accept requests via IPv4.
4537 Where a hostname is specified, the +'first'+ returned address is used
4538 which matches the socket type is used.
4540 The special type 'pipe' isn't really a socket.
4542 lassign [socket pipe] r w
4544 # Must close $w after exec
4552 +*syslog* '?options? ?priority? message'+
4554 This command sends message to system syslog facility with given
4555 priority. Valid priorities are:
4557 emerg, alert, crit, err, error, warning, notice, info, debug
4559 If a message is specified, but no priority is specified, then a
4560 priority of info is used.
4562 By default, facility user is used and the value of global tcl variable
4563 argv0 is used as ident string. However, any of the following options
4564 may be specified before priority to control these parameters:
4566 +*-facility* 'value'+::
4567 Use specified facility instead of user. The following
4568 values for facility are recognized:
4570 authpriv, cron, daemon, kernel, lpr, mail, news, syslog, user,
4573 +*-ident* 'string'+::
4574 Use given string instead of argv0 variable for ident string.
4576 +*-options* 'integer'+::
4577 Set syslog options such as +LOG_CONS+, +LOG_NDELAY+. You should
4578 use numeric values of those from your system syslog.h file,
4579 because I haven't got time to implement yet another hash
4584 The optional 'pack' extension provides commands to encode and decode binary strings.
4586 +*pack* 'varName value' *-intle|-intbe|-str* 'bitwidth ?bitoffset?'+::
4587 Packs the binary representation of +'value'+ into the variable
4588 +'varName'+. The value is packed according to the given type
4589 (integer/string, big-endian/little-endian), width and bit offset.
4590 The variable is created if necessary (like `append`).
4591 Ihe variable is expanded if necessary.
4593 +*unpack* 'binvalue' *-intbe|-intle|-uintbe|-uintle|-str* 'bitpos bitwidth'+::
4594 Unpacks bits from +'binvalue'+ at bit position +'bitpos'+ and with +'bitwidth'+.
4595 Interprets the value according to the type (integer/string, big-endian/little-endian
4596 and signed/unsigned) and returns it. For integer types, +'bitwidth'+
4597 may be up to the size of a Jim Tcl integer (typically 64 bits). For the string type,
4598 both the width and the offset must be on a byte boundary (multiple of 8). Attempting to
4599 access outside the length of the value will return 0 for integer types or the empty string
4600 for the string type.
4604 The optional, pure-Tcl 'binary' extension provides the Tcl-compatible `binary scan` and `binary format`
4605 commands based on the low-level `pack` and `unpack` commands.
4607 See the Tcl documentation at: http://www.tcl.tk/man/tcl8.5/TclCmd/binary.htm
4609 Note that packing and unpacking of floating point values is not supported.
4613 The optional, pure-Tcl 'oo' extension provides object-oriented (OO) support for Jim Tcl.
4615 See the online documentation (http://jim.berlios.de/documentation/oo/) for more details.
4617 +*class* 'classname ?baseclasses? classvars'+::
4618 Create a new class, +'classname'+, with the given dictionary
4619 (+'classvars'+) as class variables. These are the initial variables
4620 which all newly created objects of this class are initialised with.
4621 If a list of baseclasses is given, methods and instance variables
4624 +*super* 'method ?args \...?'+::
4625 From within a method, invokes the given method on the base class.
4626 Note that this will only call the last baseclass given.
4630 The optional, pure-Tcl 'tree' extension implements an OO, general purpose tree structure
4631 similar to that provided by tcllib ::struct::tree (http://tcllib.sourceforge.net/doc/struct_tree.html)
4633 A tree is a collection of nodes, where each node (except the root node) has a single parent
4634 and zero or more child nodes (ordered), as well as zero or more attribute/value pairs.
4637 Creates and returns a new tree object with a single node named "root".
4638 All operations on the tree are invoked through this object.
4641 Destroy the tree and all it's nodes. (Note that the the tree will also
4642 be automatically garbage collected once it goes out of scope).
4644 +$tree *set* 'nodename key value'+::
4645 Set the value for the given attribute key.
4647 +$tree *lappend* 'nodename key value \...'+::
4648 Append to the (list) value(s) for the given attribute key, or set if not yet set.
4650 +$tree *keyexists* 'nodename key'+::
4651 Returns 1 if the given attribute key exists.
4653 +$tree *get* 'nodename key'+::
4654 Returns the value associated with the given attribute key.
4656 +$tree *getall* 'nodename'+::
4657 Returns the entire attribute dictionary associated with the given key.
4659 +$tree *depth* 'nodename'+::
4660 Returns the depth of the given node. The depth of "root" is 0.
4662 +$tree *parent* 'nodename'+::
4663 Returns the node name of the parent node, or "" for the root node.
4665 +$tree *numchildren* 'nodename'+::
4666 Returns the number of child nodes.
4668 +$tree *children* 'nodename'+::
4669 Returns a list of the child nodes.
4671 +$tree *next* 'nodename'+::
4672 Returns the next sibling node, or "" if none.
4674 +$tree *insert* 'nodename ?index?'+::
4675 Add a new child node to the given node. The index is a list index
4676 such as +3+ or +end-2+. The default index is +end+.
4677 Returns the name of the newly added node.
4679 +$tree *walk* 'nodename' *dfs|bfs* {'actionvar nodevar'} 'script'+::
4680 Walks the tree starting from the given node, either breadth first (+bfs+)
4681 depth first (+dfs+).
4682 The value +"enter"+ or +"exit"+ is stored in variable +'actionvar'+.
4683 The name of each node is stored in +'nodevar'+.
4684 The script is evaluated twice for each node, on entry and exit.
4687 Dumps the tree contents to stdout
4689 [[BuiltinVariables]]
4693 The following global variables are created automatically
4697 This variable is set by Jim as an array
4698 whose elements are the environment variables for the process.
4699 Reading an element will return the value of the corresponding
4700 environment variable.
4701 This array is initialised at startup from the `env` command.
4702 It may be modified and will affect the environment passed to
4703 commands invoked with `exec`.
4706 This variable is set by Jim as an array containing information
4707 about the platform on which Jim was built. Currently this includes
4708 'os' and 'platform'.
4711 This variable contains a list of paths to search for packages.
4712 It defaults to a location based on where jim is installed
4713 (e.g. +/usr/local/lib/jim+), but may be changed by +jimsh+
4714 or the embedding application. Note that +jimsh+ will consider
4715 the environment variable +$JIMLIB+ to be a list of colon-separated
4716 list of paths to add to +*auto_path*+.
4719 This variable holds the value of the -errorcode return
4720 option set by the most recent error that occurred in this
4721 interpreter. This list value represents additional information
4722 about the error in a form that is easy to process with
4723 programs. The first element of the list identifies a general
4724 class of errors, and determines the format of the rest of
4725 the list. The following formats for -errorcode return options
4726 are used by the Tcl core; individual applications may define
4727 additional formats. Currently only `exec` sets this variable.
4728 Otherwise it will be +NONE+.
4730 The following global variables are set by jimsh.
4732 +*tcl_interactive*+::
4733 This variable is set to 1 if jimsh is started in interactive mode
4737 This variable is set by Jim as an array containing information
4738 about the platform upon which Jim was built. The following is an
4739 example of the contents of this array.
4741 tcl_platform(byteOrder) = littleEndian
4742 tcl_platform(os) = Darwin
4743 tcl_platform(platform) = unix
4744 tcl_platform(pointerSize) = 8
4745 tcl_platform(threaded) = 0
4746 tcl_platform(wordSize) = 8
4747 tcl_platform(pathSeparator) = :
4750 If jimsh is invoked to run a script, this variable contains the name
4754 If jimsh is invoked to run a script, this variable contains a list
4755 of any arguments supplied to the script.
4758 If jimsh is invoked to run a script, this variable contains the number
4759 of arguments supplied to the script.
4762 The value of argv[0] when jimsh was invoked.
4764 CHANGES IN PREVIOUS RELEASES
4765 ----------------------------
4769 1. `source` now checks that a script is complete (.i.e. not missing a brace)
4770 2. 'info complete' now uses the real parser and so is 100% accurate
4771 3. Better access to live stack frames with 'info frame', `stacktrace` and `stackdump`
4772 4. `tailcall` no longer loses stack trace information
4773 5. Add `alias` and `curry`
4774 6. `lambda`, `alias` and `curry` are implemented via `tailcall` for efficiency
4775 7. `local` allows procedures to be deleted automatically at the end of the current procedure
4776 8. udp sockets are now supported for both clients and servers.
4777 9. vfork-based exec is now working correctly
4778 10. Add 'file tempfile'
4779 11. Add 'socket pipe'
4780 12. Enhance 'try ... on ... finally' to be more Tcl 8.6 compatible
4781 13. It is now possible to `return` from within `try`
4782 14. IPv6 support is now included
4784 16. Event handlers works better if an error occurs. eof handler has been removed.
4785 17. `exec` now sets $::errorCode, and catch sets opts(-errorcode) for exit status
4786 18. Command pipelines via open "|..." are now supported
4787 19. `pid` can now return pids of a command pipeline
4788 20. Add 'info references'
4789 21. Add support for 'after +'ms'+', 'after idle', 'after info', `update`
4790 22. `exec` now sets environment based on $::env
4792 24. Add support for 'lsort -index'
4796 1. Add support to `exec` for '>&', '>>&', '|&', '2>@1'
4797 2. Fix `exec` error messages when special token (e.g. '>') is the last token
4798 3. Fix `subst` handling of backslash escapes.
4799 4. Allow abbreviated options for `subst`
4800 5. Add support for `return`, `break`, `continue` in subst
4801 6. Many `expr` bug fixes
4802 7. Add support for functions in `expr` (e.g. int(), abs()), and also 'in', 'ni' list operations
4803 8. The variable name argument to `regsub` is now optional
4804 9. Add support for 'unset -nocomplain'
4805 10. Add support for list commands: `lassign`, `lrepeat`
4806 11. Fully-functional `lsearch` is now implemented
4807 12. Add 'info nameofexecutable' and 'info returncodes'
4808 13. Allow `catch` to determine what return codes are caught
4809 14. Allow `incr` to increment an unset variable by first setting to 0
4810 15. Allow 'args' and optional arguments to the left or required arguments in `proc`
4812 17. Add 'try ... finally' command
4818 Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
4819 Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
4820 Copyright 2005 patthoyts - Pat Thoyts <patthoyts@users.sf.net>
4821 Copyright 2008 oharboe - Oyvind Harboe - oyvind.harboe@zylin.com
4822 Copyright 2008 Andrew Lunn <andrew@lunn.ch>
4823 Copyright 2008 Duane Ellis <openocd@duaneellis.com>
4824 Copyright 2008 Uwe Klein <uklein@klein-messgeraete.de>
4825 Copyright 2009 Steve Bennett <steveb@workware.net.au>
4828 Redistribution and use in source and binary forms, with or without
4829 modification, are permitted provided that the following conditions
4831 1. Redistributions of source code must retain the above copyright
4832 notice, this list of conditions and the following disclaimer.
4833 2. Redistributions in binary form must reproduce the above
4834 copyright notice, this list of conditions and the following
4835 disclaimer in the documentation and/or other materials
4836 provided with the distribution.
4838 THIS SOFTWARE IS PROVIDED BY THE JIM TCL PROJECT ``AS IS'' AND ANY
4839 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
4840 THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
4841 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
4842 JIM TCL PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
4843 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
4844 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
4845 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
4846 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
4847 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
4848 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
4849 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
4851 The views and conclusions contained in the software and documentation
4852 are those of the authors and should not be interpreted as representing
4853 official policies, either expressed or implied, of the Jim Tcl Project.