| 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. |