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1 | '\" |
2 | '\" Copyright (c) 1993 The Regents of the University of California. | |
3 | '\" Copyright (c) 1994-1996 Sun Microsystems, Inc. | |
4 | '\" | |
5 | '\" See the file "license.terms" for information on usage and redistribution | |
6 | '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. | |
7 | '\" | |
8 | '\" RCS: @(#) $Id: Tcl.n,v 1.9 2003/02/01 19:48:23 kennykb Exp $ | |
9 | '\" | |
10 | '\" The definitions below are for supplemental macros used in Tcl/Tk | |
11 | '\" manual entries. | |
12 | '\" | |
13 | '\" .AP type name in/out ?indent? | |
14 | '\" Start paragraph describing an argument to a library procedure. | |
15 | '\" type is type of argument (int, etc.), in/out is either "in", "out", | |
16 | '\" or "in/out" to describe whether procedure reads or modifies arg, | |
17 | '\" and indent is equivalent to second arg of .IP (shouldn't ever be | |
18 | '\" needed; use .AS below instead) | |
19 | '\" | |
20 | '\" .AS ?type? ?name? | |
21 | '\" Give maximum sizes of arguments for setting tab stops. Type and | |
22 | '\" name are examples of largest possible arguments that will be passed | |
23 | '\" to .AP later. If args are omitted, default tab stops are used. | |
24 | '\" | |
25 | '\" .BS | |
26 | '\" Start box enclosure. From here until next .BE, everything will be | |
27 | '\" enclosed in one large box. | |
28 | '\" | |
29 | '\" .BE | |
30 | '\" End of box enclosure. | |
31 | '\" | |
32 | '\" .CS | |
33 | '\" Begin code excerpt. | |
34 | '\" | |
35 | '\" .CE | |
36 | '\" End code excerpt. | |
37 | '\" | |
38 | '\" .VS ?version? ?br? | |
39 | '\" Begin vertical sidebar, for use in marking newly-changed parts | |
40 | '\" of man pages. The first argument is ignored and used for recording | |
41 | '\" the version when the .VS was added, so that the sidebars can be | |
42 | '\" found and removed when they reach a certain age. If another argument | |
43 | '\" is present, then a line break is forced before starting the sidebar. | |
44 | '\" | |
45 | '\" .VE | |
46 | '\" End of vertical sidebar. | |
47 | '\" | |
48 | '\" .DS | |
49 | '\" Begin an indented unfilled display. | |
50 | '\" | |
51 | '\" .DE | |
52 | '\" End of indented unfilled display. | |
53 | '\" | |
54 | '\" .SO | |
55 | '\" Start of list of standard options for a Tk widget. The | |
56 | '\" options follow on successive lines, in four columns separated | |
57 | '\" by tabs. | |
58 | '\" | |
59 | '\" .SE | |
60 | '\" End of list of standard options for a Tk widget. | |
61 | '\" | |
62 | '\" .OP cmdName dbName dbClass | |
63 | '\" Start of description of a specific option. cmdName gives the | |
64 | '\" option's name as specified in the class command, dbName gives | |
65 | '\" the option's name in the option database, and dbClass gives | |
66 | '\" the option's class in the option database. | |
67 | '\" | |
68 | '\" .UL arg1 arg2 | |
69 | '\" Print arg1 underlined, then print arg2 normally. | |
70 | '\" | |
71 | '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $ | |
72 | '\" | |
73 | '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. | |
74 | .if t .wh -1.3i ^B | |
75 | .nr ^l \n(.l | |
76 | .ad b | |
77 | '\" # Start an argument description | |
78 | .de AP | |
79 | .ie !"\\$4"" .TP \\$4 | |
80 | .el \{\ | |
81 | . ie !"\\$2"" .TP \\n()Cu | |
82 | . el .TP 15 | |
83 | .\} | |
84 | .ta \\n()Au \\n()Bu | |
85 | .ie !"\\$3"" \{\ | |
86 | \&\\$1 \\fI\\$2\\fP (\\$3) | |
87 | .\".b | |
88 | .\} | |
89 | .el \{\ | |
90 | .br | |
91 | .ie !"\\$2"" \{\ | |
92 | \&\\$1 \\fI\\$2\\fP | |
93 | .\} | |
94 | .el \{\ | |
95 | \&\\fI\\$1\\fP | |
96 | .\} | |
97 | .\} | |
98 | .. | |
99 | '\" # define tabbing values for .AP | |
100 | .de AS | |
101 | .nr )A 10n | |
102 | .if !"\\$1"" .nr )A \\w'\\$1'u+3n | |
103 | .nr )B \\n()Au+15n | |
104 | .\" | |
105 | .if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n | |
106 | .nr )C \\n()Bu+\\w'(in/out)'u+2n | |
107 | .. | |
108 | .AS Tcl_Interp Tcl_CreateInterp in/out | |
109 | '\" # BS - start boxed text | |
110 | '\" # ^y = starting y location | |
111 | '\" # ^b = 1 | |
112 | .de BS | |
113 | .br | |
114 | .mk ^y | |
115 | .nr ^b 1u | |
116 | .if n .nf | |
117 | .if n .ti 0 | |
118 | .if n \l'\\n(.lu\(ul' | |
119 | .if n .fi | |
120 | .. | |
121 | '\" # BE - end boxed text (draw box now) | |
122 | .de BE | |
123 | .nf | |
124 | .ti 0 | |
125 | .mk ^t | |
126 | .ie n \l'\\n(^lu\(ul' | |
127 | .el \{\ | |
128 | .\" Draw four-sided box normally, but don't draw top of | |
129 | .\" box if the box started on an earlier page. | |
130 | .ie !\\n(^b-1 \{\ | |
131 | \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' | |
132 | .\} | |
133 | .el \}\ | |
134 | \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' | |
135 | .\} | |
136 | .\} | |
137 | .fi | |
138 | .br | |
139 | .nr ^b 0 | |
140 | .. | |
141 | '\" # VS - start vertical sidebar | |
142 | '\" # ^Y = starting y location | |
143 | '\" # ^v = 1 (for troff; for nroff this doesn't matter) | |
144 | .de VS | |
145 | .if !"\\$2"" .br | |
146 | .mk ^Y | |
147 | .ie n 'mc \s12\(br\s0 | |
148 | .el .nr ^v 1u | |
149 | .. | |
150 | '\" # VE - end of vertical sidebar | |
151 | .de VE | |
152 | .ie n 'mc | |
153 | .el \{\ | |
154 | .ev 2 | |
155 | .nf | |
156 | .ti 0 | |
157 | .mk ^t | |
158 | \h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n' | |
159 | .sp -1 | |
160 | .fi | |
161 | .ev | |
162 | .\} | |
163 | .nr ^v 0 | |
164 | .. | |
165 | '\" # Special macro to handle page bottom: finish off current | |
166 | '\" # box/sidebar if in box/sidebar mode, then invoked standard | |
167 | '\" # page bottom macro. | |
168 | .de ^B | |
169 | .ev 2 | |
170 | 'ti 0 | |
171 | 'nf | |
172 | .mk ^t | |
173 | .if \\n(^b \{\ | |
174 | .\" Draw three-sided box if this is the box's first page, | |
175 | .\" draw two sides but no top otherwise. | |
176 | .ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c | |
177 | .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c | |
178 | .\} | |
179 | .if \\n(^v \{\ | |
180 | .nr ^x \\n(^tu+1v-\\n(^Yu | |
181 | \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c | |
182 | .\} | |
183 | .bp | |
184 | 'fi | |
185 | .ev | |
186 | .if \\n(^b \{\ | |
187 | .mk ^y | |
188 | .nr ^b 2 | |
189 | .\} | |
190 | .if \\n(^v \{\ | |
191 | .mk ^Y | |
192 | .\} | |
193 | .. | |
194 | '\" # DS - begin display | |
195 | .de DS | |
196 | .RS | |
197 | .nf | |
198 | .sp | |
199 | .. | |
200 | '\" # DE - end display | |
201 | .de DE | |
202 | .fi | |
203 | .RE | |
204 | .sp | |
205 | .. | |
206 | '\" # SO - start of list of standard options | |
207 | .de SO | |
208 | .SH "STANDARD OPTIONS" | |
209 | .LP | |
210 | .nf | |
211 | .ta 5.5c 11c | |
212 | .ft B | |
213 | .. | |
214 | '\" # SE - end of list of standard options | |
215 | .de SE | |
216 | .fi | |
217 | .ft R | |
218 | .LP | |
219 | See the \\fBoptions\\fR manual entry for details on the standard options. | |
220 | .. | |
221 | '\" # OP - start of full description for a single option | |
222 | .de OP | |
223 | .LP | |
224 | .nf | |
225 | .ta 4c | |
226 | Command-Line Name: \\fB\\$1\\fR | |
227 | Database Name: \\fB\\$2\\fR | |
228 | Database Class: \\fB\\$3\\fR | |
229 | .fi | |
230 | .IP | |
231 | .. | |
232 | '\" # CS - begin code excerpt | |
233 | .de CS | |
234 | .RS | |
235 | .nf | |
236 | .ta .25i .5i .75i 1i | |
237 | .. | |
238 | '\" # CE - end code excerpt | |
239 | .de CE | |
240 | .fi | |
241 | .RE | |
242 | .. | |
243 | .de UL | |
244 | \\$1\l'|0\(ul'\\$2 | |
245 | .. | |
246 | .TH Tcl n "8.1" Tcl "Tcl Built-In Commands" | |
247 | .BS | |
248 | .SH NAME | |
249 | Tcl \- Tool Command Language | |
250 | .SH SYNOPSIS | |
251 | Summary of Tcl language syntax. | |
252 | .BE | |
253 | .SH DESCRIPTION | |
254 | .PP | |
255 | The following rules define the syntax and semantics of the Tcl language: | |
256 | .IP "[1] \fBCommands.\fR" | |
257 | A Tcl script is a string containing one or more commands. | |
258 | Semi-colons and newlines are command separators unless quoted as | |
259 | described below. | |
260 | Close brackets are command terminators during command substitution | |
261 | (see below) unless quoted. | |
262 | .IP "[2] \fBEvaluation.\fR" | |
263 | A command is evaluated in two steps. | |
264 | First, the Tcl interpreter breaks the command into \fIwords\fR | |
265 | and performs substitutions as described below. | |
266 | These substitutions are performed in the same way for all | |
267 | commands. | |
268 | The first word is used to locate a command procedure to | |
269 | carry out the command, then all of the words of the command are | |
270 | passed to the command procedure. | |
271 | The command procedure is free to interpret each of its words | |
272 | in any way it likes, such as an integer, variable name, list, | |
273 | or Tcl script. | |
274 | Different commands interpret their words differently. | |
275 | .IP "[3] \fBWords.\fR" | |
276 | Words of a command are separated by white space (except for | |
277 | newlines, which are command separators). | |
278 | .IP "[4] \fBDouble quotes.\fR" | |
279 | If the first character of a word is double-quote (``"'') then | |
280 | the word is terminated by the next double-quote character. | |
281 | If semi-colons, close brackets, or white space characters | |
282 | (including newlines) appear between the quotes then they are treated | |
283 | as ordinary characters and included in the word. | |
284 | Command substitution, variable substitution, and backslash substitution | |
285 | are performed on the characters between the quotes as described below. | |
286 | The double-quotes are not retained as part of the word. | |
287 | .IP "[5] \fBBraces.\fR" | |
288 | If the first character of a word is an open brace (``{'') then | |
289 | the word is terminated by the matching close brace (``}''). | |
290 | Braces nest within the word: for each additional open | |
291 | brace there must be an additional close brace (however, | |
292 | if an open brace or close brace within the word is | |
293 | quoted with a backslash then it is not counted in locating the | |
294 | matching close brace). | |
295 | No substitutions are performed on the characters between the | |
296 | braces except for backslash-newline substitutions described | |
297 | below, nor do semi-colons, newlines, close brackets, | |
298 | or white space receive any special interpretation. | |
299 | The word will consist of exactly the characters between the | |
300 | outer braces, not including the braces themselves. | |
301 | .IP "[6] \fBCommand substitution.\fR" | |
302 | If a word contains an open bracket (``['') then Tcl performs | |
303 | \fIcommand substitution\fR. | |
304 | To do this it invokes the Tcl interpreter recursively to process | |
305 | the characters following the open bracket as a Tcl script. | |
306 | The script may contain any number of commands and must be terminated | |
307 | by a close bracket (``]''). | |
308 | The result of the script (i.e. the result of its last command) is | |
309 | substituted into the word in place of the brackets and all of the | |
310 | characters between them. | |
311 | There may be any number of command substitutions in a single word. | |
312 | Command substitution is not performed on words enclosed in braces. | |
313 | .IP "[7] \fBVariable substitution.\fR" | |
314 | If a word contains a dollar-sign (``$'') then Tcl performs \fIvariable | |
315 | substitution\fR: the dollar-sign and the following characters are | |
316 | replaced in the word by the value of a variable. | |
317 | Variable substitution may take any of the following forms: | |
318 | .RS | |
319 | .TP 15 | |
320 | \fB$\fIname\fR | |
321 | \fIName\fR is the name of a scalar variable; the name is a sequence | |
322 | of one or more characters that are a letter, digit, underscore, | |
323 | or namespace separators (two or more colons). | |
324 | .TP 15 | |
325 | \fB$\fIname\fB(\fIindex\fB)\fR | |
326 | \fIName\fR gives the name of an array variable and \fIindex\fR gives | |
327 | the name of an element within that array. | |
328 | \fIName\fR must contain only letters, digits, underscores, and | |
329 | namespace separators, and may be an empty string. | |
330 | Command substitutions, variable substitutions, and backslash | |
331 | substitutions are performed on the characters of \fIindex\fR. | |
332 | .TP 15 | |
333 | \fB${\fIname\fB}\fR | |
334 | \fIName\fR is the name of a scalar variable. It may contain any | |
335 | characters whatsoever except for close braces. | |
336 | .LP | |
337 | There may be any number of variable substitutions in a single word. | |
338 | Variable substitution is not performed on words enclosed in braces. | |
339 | .RE | |
340 | .IP "[8] \fBBackslash substitution.\fR" | |
341 | If a backslash (``\e'') appears within a word then | |
342 | \fIbackslash substitution\fR occurs. | |
343 | In all cases but those described below the backslash is dropped and | |
344 | the following character is treated as an ordinary | |
345 | character and included in the word. | |
346 | This allows characters such as double quotes, close brackets, | |
347 | and dollar signs to be included in words without triggering | |
348 | special processing. | |
349 | The following table lists the backslash sequences that are | |
350 | handled specially, along with the value that replaces each sequence. | |
351 | .RS | |
352 | .TP 7 | |
353 | \e\fBa\fR | |
354 | Audible alert (bell) (0x7). | |
355 | .TP 7 | |
356 | \e\fBb\fR | |
357 | Backspace (0x8). | |
358 | .TP 7 | |
359 | \e\fBf\fR | |
360 | Form feed (0xc). | |
361 | .TP 7 | |
362 | \e\fBn\fR | |
363 | Newline (0xa). | |
364 | .TP 7 | |
365 | \e\fBr\fR | |
366 | Carriage-return (0xd). | |
367 | .TP 7 | |
368 | \e\fBt\fR | |
369 | Tab (0x9). | |
370 | .TP 7 | |
371 | \e\fBv\fR | |
372 | Vertical tab (0xb). | |
373 | .TP 7 | |
374 | \e\fB<newline>\fIwhiteSpace\fR | |
375 | . | |
376 | A single space character replaces the backslash, newline, and all spaces | |
377 | and tabs after the newline. This backslash sequence is unique in that it | |
378 | is replaced in a separate pre-pass before the command is actually parsed. | |
379 | This means that it will be replaced even when it occurs between braces, | |
380 | and the resulting space will be treated as a word separator if it isn't | |
381 | in braces or quotes. | |
382 | .TP 7 | |
383 | \e\e | |
384 | Backslash (``\e''). | |
385 | .VS 8.1 br | |
386 | .TP 7 | |
387 | \e\fIooo\fR | |
388 | . | |
389 | The digits \fIooo\fR (one, two, or three of them) give an eight-bit octal | |
390 | value for the Unicode character that will be inserted. The upper bits of the | |
391 | Unicode character will be 0. | |
392 | .TP 7 | |
393 | \e\fBx\fIhh\fR | |
394 | . | |
395 | The hexadecimal digits \fIhh\fR give an eight-bit hexadecimal value for the | |
396 | Unicode character that will be inserted. Any number of hexadecimal digits | |
397 | may be present; however, all but the last two are ignored (the result is | |
398 | always a one-byte quantity). The upper bits of the Unicode character will | |
399 | be 0. | |
400 | .TP 7 | |
401 | \e\fBu\fIhhhh\fR | |
402 | . | |
403 | The hexadecimal digits \fIhhhh\fR (one, two, three, or four of them) give a | |
404 | sixteen-bit hexadecimal value for the Unicode character that will be | |
405 | inserted. | |
406 | .VE | |
407 | .LP | |
408 | Backslash substitution is not performed on words enclosed in braces, | |
409 | except for backslash-newline as described above. | |
410 | .RE | |
411 | .IP "[9] \fBComments.\fR" | |
412 | If a hash character (``#'') appears at a point where Tcl is | |
413 | expecting the first character of the first word of a command, | |
414 | then the hash character and the characters that follow it, up | |
415 | through the next newline, are treated as a comment and ignored. | |
416 | The comment character only has significance when it appears | |
417 | at the beginning of a command. | |
418 | .IP "[10] \fBOrder of substitution.\fR" | |
419 | Each character is processed exactly once by the Tcl interpreter | |
420 | as part of creating the words of a command. | |
421 | For example, if variable substitution occurs then no further | |
422 | substitutions are performed on the value of the variable; the | |
423 | value is inserted into the word verbatim. | |
424 | If command substitution occurs then the nested command is | |
425 | processed entirely by the recursive call to the Tcl interpreter; | |
426 | no substitutions are performed before making the recursive | |
427 | call and no additional substitutions are performed on the result | |
428 | of the nested script. | |
429 | .RS | |
430 | .LP | |
431 | Substitutions take place from left to right, and each substitution is | |
432 | evaluated completely before attempting to evaluate the next. Thus, a | |
433 | sequence like | |
434 | .CS | |
435 | set y [set x 0][incr x][incr x] | |
436 | .CE | |
437 | will always set the variable \fIy\fR to the value, \fI012\fR. | |
438 | .RE | |
439 | .IP "[11] \fBSubstitution and word boundaries.\fR" | |
440 | Substitutions do not affect the word boundaries of a command. | |
441 | For example, during variable substitution the entire value of | |
442 | the variable becomes part of a single word, even if the variable's | |
443 | value contains spaces. |