| 1 | '\" |
| 2 | '\" Copyright (c) 1993 The Regents of the University of California. |
| 3 | '\" Copyright (c) 1994-1997 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: tclvars.n,v 1.13.2.2 2004/11/16 10:07:00 dkf 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 tclvars n 8.0 Tcl "Tcl Built-In Commands" |
| 247 | .BS |
| 248 | '\" Note: do not modify the .SH NAME line immediately below! |
| 249 | .SH NAME |
| 250 | tclvars \- Variables used by Tcl |
| 251 | .BE |
| 252 | |
| 253 | .SH DESCRIPTION |
| 254 | .PP |
| 255 | The following global variables are created and managed automatically |
| 256 | by the Tcl library. Except where noted below, these variables should |
| 257 | normally be treated as read-only by application-specific code and by users. |
| 258 | .TP |
| 259 | \fBenv\fR |
| 260 | This variable is maintained by Tcl as an array |
| 261 | whose elements are the environment variables for the process. |
| 262 | Reading an element will return the value of the corresponding |
| 263 | environment variable. |
| 264 | Setting an element of the array will modify the corresponding |
| 265 | environment variable or create a new one if it doesn't already |
| 266 | exist. |
| 267 | Unsetting an element of \fBenv\fR will remove the corresponding |
| 268 | environment variable. |
| 269 | Changes to the \fBenv\fR array will affect the environment |
| 270 | passed to children by commands like \fBexec\fR. |
| 271 | If the entire \fBenv\fR array is unset then Tcl will stop |
| 272 | monitoring \fBenv\fR accesses and will not update environment |
| 273 | variables. |
| 274 | .RS |
| 275 | .VS 8.0 |
| 276 | Under Windows, the environment variables PATH and COMSPEC in any |
| 277 | capitalization are converted automatically to upper case. For instance, the |
| 278 | PATH variable could be exported by the operating system as ``path'', |
| 279 | ``Path'', ``PaTh'', etc., causing otherwise simple Tcl code to have to |
| 280 | support many special cases. All other environment variables inherited by |
| 281 | Tcl are left unmodified. Setting an env array variable to blank is the |
| 282 | same as unsetting it as this is the behavior of the underlying Windows OS. |
| 283 | It should be noted that relying on an existing and empty environment variable |
| 284 | won't work on windows and is discouraged for cross-platform usage. |
| 285 | .VE |
| 286 | .RE |
| 287 | .RS |
| 288 | On the Macintosh, the environment variable is constructed by Tcl as no |
| 289 | global environment variable exists. The environment variables that |
| 290 | are created for Tcl include: |
| 291 | .TP |
| 292 | \fBLOGIN\fR |
| 293 | This holds the Chooser name of the Macintosh. |
| 294 | .TP |
| 295 | \fBUSER\fR |
| 296 | This also holds the Chooser name of the Macintosh. |
| 297 | .TP |
| 298 | \fBSYS_FOLDER\fR |
| 299 | The path to the system directory. |
| 300 | .TP |
| 301 | \fBAPPLE_M_FOLDER\fR |
| 302 | The path to the Apple Menu directory. |
| 303 | .TP |
| 304 | \fBCP_FOLDER\fR |
| 305 | The path to the control panels directory. |
| 306 | .TP |
| 307 | \fBDESK_FOLDER\fR |
| 308 | The path to the desk top directory. |
| 309 | .TP |
| 310 | \fBEXT_FOLDER\fR |
| 311 | The path to the system extensions directory. |
| 312 | .TP |
| 313 | \fBPREF_FOLDER\fR |
| 314 | The path to the preferences directory. |
| 315 | .TP |
| 316 | \fBPRINT_MON_FOLDER\fR |
| 317 | The path to the print monitor directory. |
| 318 | .TP |
| 319 | \fBSHARED_TRASH_FOLDER\fR |
| 320 | The path to the network trash directory. |
| 321 | .TP |
| 322 | \fBTRASH_FOLDER\fR |
| 323 | The path to the trash directory. |
| 324 | .TP |
| 325 | \fBSTART_UP_FOLDER\fR |
| 326 | The path to the start up directory. |
| 327 | .TP |
| 328 | \fBHOME\fR |
| 329 | The path to the application's default directory. |
| 330 | .PP |
| 331 | You can also create your own environment variables for the Macintosh. |
| 332 | A file named \fITcl Environment Variables\fR may be placed in the |
| 333 | preferences folder in the Mac system folder. Each line of this file |
| 334 | should be of the form \fIVAR_NAME=var_data\fR. |
| 335 | .PP |
| 336 | The last alternative is to place environment variables in a 'STR#' |
| 337 | resource named \fITcl Environment Variables\fR of the application. This |
| 338 | is considered a little more ``Mac like'' than a Unix style Environment |
| 339 | Variable file. Each entry in the 'STR#' resource has the same format |
| 340 | as above. The source code file \fItclMacEnv.c\fR contains the |
| 341 | implementation of the env mechanisms. This file contains many |
| 342 | #define's that allow customization of the env mechanisms to fit your |
| 343 | applications needs. |
| 344 | .RE |
| 345 | .TP |
| 346 | \fBerrorCode\fR |
| 347 | After an error has occurred, this variable will be set to hold |
| 348 | additional information about the error in a form that is easy |
| 349 | to process with programs. |
| 350 | \fBerrorCode\fR consists of a Tcl list with one or more elements. |
| 351 | The first element of the list identifies a general class of |
| 352 | errors, and determines the format of the rest of the list. |
| 353 | The following formats for \fBerrorCode\fR are used by the |
| 354 | Tcl core; individual applications may define additional formats. |
| 355 | .RS |
| 356 | .TP |
| 357 | \fBARITH\fI code msg\fR |
| 358 | This format is used when an arithmetic error occurs (e.g. an attempt |
| 359 | to divide by zero in the \fBexpr\fR command). |
| 360 | \fICode\fR identifies the precise error and \fImsg\fR provides a |
| 361 | human-readable description of the error. \fICode\fR will be either |
| 362 | DIVZERO (for an attempt to divide by zero), |
| 363 | DOMAIN (if an argument is outside the domain of a function, such as acos(\-3)), |
| 364 | IOVERFLOW (for integer overflow), |
| 365 | OVERFLOW (for a floating-point overflow), |
| 366 | or UNKNOWN (if the cause of the error cannot be determined). |
| 367 | .TP |
| 368 | \fBCHILDKILLED\fI pid sigName msg\fR |
| 369 | This format is used when a child process has been killed because of |
| 370 | a signal. The second element of \fBerrorCode\fR will be the |
| 371 | process's identifier (in decimal). |
| 372 | The third element will be the symbolic name of the signal that caused |
| 373 | the process to terminate; it will be one of the names from the |
| 374 | include file signal.h, such as \fBSIGPIPE\fR. |
| 375 | The fourth element will be a short human-readable message |
| 376 | describing the signal, such as ``write on pipe with no readers'' |
| 377 | for \fBSIGPIPE\fR. |
| 378 | .TP |
| 379 | \fBCHILDSTATUS\fI pid code\fR |
| 380 | This format is used when a child process has exited with a non-zero |
| 381 | exit status. The second element of \fBerrorCode\fR will be the |
| 382 | process's identifier (in decimal) and the third element will be the exit |
| 383 | code returned by the process (also in decimal). |
| 384 | .TP |
| 385 | \fBCHILDSUSP\fI pid sigName msg\fR |
| 386 | This format is used when a child process has been suspended because |
| 387 | of a signal. |
| 388 | The second element of \fBerrorCode\fR will be the process's identifier, |
| 389 | in decimal. |
| 390 | The third element will be the symbolic name of the signal that caused |
| 391 | the process to suspend; this will be one of the names from the |
| 392 | include file signal.h, such as \fBSIGTTIN\fR. |
| 393 | The fourth element will be a short human-readable message |
| 394 | describing the signal, such as ``background tty read'' |
| 395 | for \fBSIGTTIN\fR. |
| 396 | .TP |
| 397 | \fBNONE\fR |
| 398 | This format is used for errors where no additional information is |
| 399 | available for an error besides the message returned with the |
| 400 | error. In these cases \fBerrorCode\fR will consist of a list |
| 401 | containing a single element whose contents are \fBNONE\fR. |
| 402 | .TP |
| 403 | \fBPOSIX \fIerrName msg\fR |
| 404 | If the first element of \fBerrorCode\fR is \fBPOSIX\fR, then |
| 405 | the error occurred during a POSIX kernel call. |
| 406 | The second element of the list will contain the symbolic name |
| 407 | of the error that occurred, such as \fBENOENT\fR; this will |
| 408 | be one of the values defined in the include file errno.h. |
| 409 | The third element of the list will be a human-readable |
| 410 | message corresponding to \fIerrName\fR, such as |
| 411 | ``no such file or directory'' for the \fBENOENT\fR case. |
| 412 | .PP |
| 413 | To set \fBerrorCode\fR, applications should use library |
| 414 | procedures such as \fBTcl_SetErrorCode\fR and \fBTcl_PosixError\fR, |
| 415 | or they may invoke the \fBerror\fR command. |
| 416 | If one of these methods hasn't been used, then the Tcl |
| 417 | interpreter will reset the variable to \fBNONE\fR after |
| 418 | the next error. |
| 419 | .RE |
| 420 | .TP |
| 421 | \fBerrorInfo\fR |
| 422 | After an error has occurred, this string will contain one or more lines |
| 423 | identifying the Tcl commands and procedures that were being executed |
| 424 | when the most recent error occurred. |
| 425 | Its contents take the form of a stack trace showing the various |
| 426 | nested Tcl commands that had been invoked at the time of the error. |
| 427 | .TP |
| 428 | \fBtcl_library\fR |
| 429 | This variable holds the name of a directory containing the |
| 430 | system library of Tcl scripts, such as those used for auto-loading. |
| 431 | The value of this variable is returned by the \fBinfo library\fR command. |
| 432 | See the \fBlibrary\fR manual entry for details of the facilities |
| 433 | provided by the Tcl script library. |
| 434 | Normally each application or package will have its own application-specific |
| 435 | script library in addition to the Tcl script library; |
| 436 | each application should set a global variable with a name like |
| 437 | \fB$\fIapp\fB_library\fR (where \fIapp\fR is the application's name) |
| 438 | to hold the network file name for that application's library directory. |
| 439 | The initial value of \fBtcl_library\fR is set when an interpreter |
| 440 | is created by searching several different directories until one is |
| 441 | found that contains an appropriate Tcl startup script. |
| 442 | If the \fBTCL_LIBRARY\fR environment variable exists, then |
| 443 | the directory it names is checked first. |
| 444 | If \fBTCL_LIBRARY\fR isn't set or doesn't refer to an appropriate |
| 445 | directory, then Tcl checks several other directories based on a |
| 446 | compiled-in default location, the location of the binary containing |
| 447 | the application, and the current working directory. |
| 448 | .TP |
| 449 | \fBtcl_patchLevel\fR |
| 450 | When an interpreter is created Tcl initializes this variable to |
| 451 | hold a string giving the current patch level for Tcl, such as |
| 452 | \fB7.3p2\fR for Tcl 7.3 with the first two official patches, or |
| 453 | \fB7.4b4\fR for the fourth beta release of Tcl 7.4. |
| 454 | The value of this variable is returned by the \fBinfo patchlevel\fR |
| 455 | command. |
| 456 | .VS 8.0 br |
| 457 | .TP |
| 458 | \fBtcl_pkgPath\fR |
| 459 | This variable holds a list of directories indicating where packages are |
| 460 | normally installed. It is not used on Windows. It typically contains |
| 461 | either one or two entries; if it contains two entries, the first is |
| 462 | normally a directory for platform-dependent packages (e.g., shared library |
| 463 | binaries) and the second is normally a directory for platform-independent |
| 464 | packages (e.g., script files). Typically a package is installed as a |
| 465 | subdirectory of one of the entries in \fB$tcl_pkgPath\fR. The directories |
| 466 | in \fB$tcl_pkgPath\fR are included by default in the \fBauto_path\fR |
| 467 | variable, so they and their immediate subdirectories are automatically |
| 468 | searched for packages during \fBpackage require\fR commands. Note: |
| 469 | \fBtcl_pkgPath\fR it not intended to be modified by the application. Its |
| 470 | value is added to \fBauto_path\fR at startup; changes to \fBtcl_pkgPath\fR |
| 471 | are not reflected in \fBauto_path\fR. If you want Tcl to search additional |
| 472 | directories for packages you should add the names of those directories to |
| 473 | \fBauto_path\fR, not \fBtcl_pkgPath\fR. |
| 474 | .VE |
| 475 | .TP |
| 476 | \fBtcl_platform\fR |
| 477 | This is an associative array whose elements contain information about |
| 478 | the platform on which the application is running, such as the name of |
| 479 | the operating system, its current release number, and the machine's |
| 480 | instruction set. The elements listed below will always |
| 481 | be defined, but they may have empty strings as values if Tcl couldn't |
| 482 | retrieve any relevant information. In addition, extensions |
| 483 | and applications may add additional values to the array. The |
| 484 | predefined elements are: |
| 485 | .RS |
| 486 | .VS |
| 487 | .TP |
| 488 | \fBbyteOrder\fR |
| 489 | The native byte order of this machine: either \fBlittleEndian\fR or |
| 490 | \fBbigEndian\fR. |
| 491 | .VE |
| 492 | .TP |
| 493 | \fBdebug\fR |
| 494 | If this variable exists, then the interpreter was compiled with and linked |
| 495 | to a debug-enabled C run-time. This variable will only exist on Windows, |
| 496 | so extension writers can specify which package to load depending on the |
| 497 | C run-time library that is in use. This is not an indication that this core |
| 498 | contains symbols. |
| 499 | .TP |
| 500 | \fBmachine\fR |
| 501 | The instruction set executed by this machine, such as |
| 502 | \fBintel\fR, \fBPPC\fR, \fB68k\fR, or \fBsun4m\fR. On UNIX machines, this |
| 503 | is the value returned by \fBuname -m\fR. |
| 504 | .TP |
| 505 | \fBos\fR |
| 506 | The name of the operating system running on this machine, |
| 507 | such as \fBWindows 95\fR, \fBWindows NT\fR, \fBMacOS\fR, or \fBSunOS\fR. |
| 508 | On UNIX machines, this is the value returned by \fBuname -s\fR. |
| 509 | On Windows 95 and Windows 98, the value returned will be \fBWindows |
| 510 | 95\fR to provide better backwards compatibility to Windows 95; to |
| 511 | distinguish between the two, check the \fBosVersion\fR. |
| 512 | .TP |
| 513 | \fBosVersion\fR |
| 514 | The version number for the operating system running on this machine. |
| 515 | On UNIX machines, this is the value returned by \fBuname -r\fR. On |
| 516 | Windows 95, the version will be 4.0; on Windows 98, the version will |
| 517 | be 4.10. |
| 518 | .TP |
| 519 | \fBplatform\fR |
| 520 | Either \fBwindows\fR, \fBmacintosh\fR, or \fBunix\fR. This identifies the |
| 521 | general operating environment of the machine. |
| 522 | .TP |
| 523 | \fBthreaded\fR |
| 524 | If this variable exists, then the interpreter |
| 525 | was compiled with threads enabled. |
| 526 | .TP |
| 527 | \fBuser\fR |
| 528 | This identifies the |
| 529 | current user based on the login information available on the platform. |
| 530 | This comes from the USER or LOGNAME environment variable on Unix, |
| 531 | and the value from GetUserName on Windows and Macintosh. |
| 532 | .TP |
| 533 | \fBwordSize\fR |
| 534 | .VS 8.4 |
| 535 | This gives the size of the native-machine word in bytes (strictly, it |
| 536 | is same as the result of evaluating \fIsizeof(long)\fR in C.) |
| 537 | .VE 8.4 |
| 538 | .RE |
| 539 | .TP |
| 540 | \fBtcl_precision\fR |
| 541 | .VS |
| 542 | This variable controls the number of digits to generate |
| 543 | when converting floating-point values to strings. It defaults |
| 544 | to 12. |
| 545 | 17 digits is ``perfect'' for IEEE floating-point in that it allows |
| 546 | double-precision values to be converted to strings and back to |
| 547 | binary with no loss of information. However, using 17 digits prevents |
| 548 | any rounding, which produces longer, less intuitive results. For example, |
| 549 | \fBexpr 1.4\fR returns 1.3999999999999999 with \fBtcl_precision\fR |
| 550 | set to 17, vs. 1.4 if \fBtcl_precision\fR is 12. |
| 551 | .RS |
| 552 | All interpreters in a process share a single \fBtcl_precision\fR value: |
| 553 | changing it in one interpreter will affect all other interpreters as |
| 554 | well. However, safe interpreters are not allowed to modify the |
| 555 | variable. |
| 556 | .RE |
| 557 | .VE |
| 558 | .TP |
| 559 | \fBtcl_rcFileName\fR |
| 560 | This variable is used during initialization to indicate the name of a |
| 561 | user-specific startup file. If it is set by application-specific |
| 562 | initialization, then the Tcl startup code will check for the existence |
| 563 | of this file and \fBsource\fR it if it exists. For example, for \fBwish\fR |
| 564 | the variable is set to \fB~/.wishrc\fR for Unix and \fB~/wishrc.tcl\fR |
| 565 | for Windows. |
| 566 | .TP |
| 567 | \fBtcl_rcRsrcName\fR |
| 568 | This variable is only used on Macintosh systems. The variable is used |
| 569 | during initialization to indicate the name of a user-specific |
| 570 | \fBTEXT\fR resource located in the application or extension resource |
| 571 | forks. If it is set by application-specific initialization, then the |
| 572 | Tcl startup code will check for the existence of this resource and |
| 573 | \fBsource\fR it if it exists. For example, the Macintosh \fBwish\fR |
| 574 | application has the variable is set to \fBtclshrc\fR. |
| 575 | .TP |
| 576 | \fBtcl_traceCompile\fR |
| 577 | The value of this variable can be set to control |
| 578 | how much tracing information |
| 579 | is displayed during bytecode compilation. |
| 580 | By default, tcl_traceCompile is zero and no information is displayed. |
| 581 | Setting tcl_traceCompile to 1 generates a one-line summary in stdout |
| 582 | whenever a procedure or top-level command is compiled. |
| 583 | Setting it to 2 generates a detailed listing in stdout of the |
| 584 | bytecode instructions emitted during every compilation. |
| 585 | This variable is useful in |
| 586 | tracking down suspected problems with the Tcl compiler. |
| 587 | It is also occasionally useful when converting |
| 588 | existing code to use Tcl8.0. |
| 589 | .PP |
| 590 | This variable and functionality only exist if |
| 591 | \fBTCL_COMPILE_DEBUG\fR was defined during Tcl's compilation. |
| 592 | .TP |
| 593 | \fBtcl_traceExec\fR |
| 594 | The value of this variable can be set to control |
| 595 | how much tracing information |
| 596 | is displayed during bytecode execution. |
| 597 | By default, tcl_traceExec is zero and no information is displayed. |
| 598 | Setting tcl_traceExec to 1 generates a one-line trace in stdout |
| 599 | on each call to a Tcl procedure. |
| 600 | Setting it to 2 generates a line of output |
| 601 | whenever any Tcl command is invoked |
| 602 | that contains the name of the command and its arguments. |
| 603 | Setting it to 3 produces a detailed trace showing the result of |
| 604 | executing each bytecode instruction. |
| 605 | Note that when tcl_traceExec is 2 or 3, |
| 606 | commands such as \fBset\fR and \fBincr\fR |
| 607 | that have been entirely replaced by a sequence |
| 608 | of bytecode instructions are not shown. |
| 609 | Setting this variable is useful in |
| 610 | tracking down suspected problems with the bytecode compiler |
| 611 | and interpreter. |
| 612 | It is also occasionally useful when converting |
| 613 | code to use Tcl8.0. |
| 614 | .PP |
| 615 | This variable and functionality only exist if |
| 616 | \fBTCL_COMPILE_DEBUG\fR was defined during Tcl's compilation. |
| 617 | .TP |
| 618 | \fBtcl_wordchars\fR |
| 619 | The value of this variable is a regular expression that can be set to |
| 620 | control what are considered ``word'' characters, for instances like |
| 621 | selecting a word by double-clicking in text in Tk. It is platform |
| 622 | dependent. On Windows, it defaults to \fB\\S\fR, meaning anything |
| 623 | but a Unicode space character. Otherwise it defaults to \fB\\w\fR, |
| 624 | which is any Unicode word character (number, letter, or underscore). |
| 625 | .TP |
| 626 | \fBtcl_nonwordchars\fR |
| 627 | The value of this variable is a regular expression that can be set to |
| 628 | control what are considered ``non-word'' characters, for instances like |
| 629 | selecting a word by double-clicking in text in Tk. It is platform |
| 630 | dependent. On Windows, it defaults to \fB\\s\fR, meaning any Unicode space |
| 631 | character. Otherwise it defaults to \fB\\W\fR, which is anything but a |
| 632 | Unicode word character (number, letter, or underscore). |
| 633 | .TP |
| 634 | \fBtcl_version\fR |
| 635 | When an interpreter is created Tcl initializes this variable to |
| 636 | hold the version number for this version of Tcl in the form \fIx.y\fR. |
| 637 | Changes to \fIx\fR represent major changes with probable |
| 638 | incompatibilities and changes to \fIy\fR represent small enhancements and |
| 639 | bug fixes that retain backward compatibility. |
| 640 | The value of this variable is returned by the \fBinfo tclversion\fR |
| 641 | command. |
| 642 | .SH "OTHER GLOBAL VARIABLES" |
| 643 | The following variables are only guaranteed to exist in \fBtclsh\fR |
| 644 | and \fBwish\fR executables; the Tcl library does not define them |
| 645 | itself but many Tcl environments do. |
| 646 | .TP 6 |
| 647 | \fBargc\fR |
| 648 | The number of arguments to \fBtclsh\fR or \fBwish\fR. |
| 649 | .TP 6 |
| 650 | \fBargv\fR |
| 651 | Tcl list of arguments to \fBtclsh\fR or \fBwish\fR. |
| 652 | .TP 6 |
| 653 | \fBargv0\fR |
| 654 | The script that \fBtclsh\fR or \fBwish\fR started executing (if it was |
| 655 | specified) or otherwise the name by which \fBtclsh\fR or \fBwish\fR |
| 656 | was invoked. |
| 657 | .TP 6 |
| 658 | \fBtcl_interactive\fR |
| 659 | Contains 1 if \fBtclsh\fR or \fBwish\fR is running interactively (no |
| 660 | script was specified and standard input is a terminal-like device), 0 |
| 661 | otherwise. |
| 662 | .PP |
| 663 | The \fBwish\fR executably additionally specifies the following global |
| 664 | variable: |
| 665 | .TP 6 |
| 666 | \fBgeometry\fR |
| 667 | If set, contains the user-supplied geometry specification to use for |
| 668 | the main Tk window. |
| 669 | |
| 670 | .SH "SEE ALSO" |
| 671 | eval(n), tclsh(1), wish(1) |
| 672 | |
| 673 | .SH KEYWORDS |
| 674 | arithmetic, bytecode, compiler, error, environment, POSIX, precision, subprocess, variables |