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| 14 | '\" .AP type name in/out ?indent? |
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| 62 | '\" |
| 63 | '\" .OP cmdName dbName dbClass |
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| 72 | '\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $ |
| 73 | '\" |
| 74 | '\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages. |
| 75 | .if t .wh -1.3i ^B |
| 76 | .nr ^l \n(.l |
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| 78 | '\" # Start an argument description |
| 79 | .de AP |
| 80 | .ie !"\\$4"" .TP \\$4 |
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| 109 | .AS Tcl_Interp Tcl_CreateInterp in/out |
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| 135 | \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul' |
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| 178 | .el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c |
| 179 | .\} |
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| 182 | \kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c |
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| 207 | '\" # SO - start of list of standard options |
| 208 | .de SO |
| 209 | .SH "STANDARD OPTIONS" |
| 210 | .LP |
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| 214 | .. |
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| 219 | .LP |
| 220 | See the \\fBoptions\\fR manual entry for details on the standard options. |
| 221 | .. |
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| 227 | Command-Line Name: \\fB\\$1\\fR |
| 228 | Database Name: \\fB\\$2\\fR |
| 229 | Database Class: \\fB\\$3\\fR |
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| 245 | \\$1\l'|0\(ul'\\$2 |
| 246 | .. |
| 247 | .TH Tcl_Eval 3 8.1 Tcl "Tcl Library Procedures" |
| 248 | .BS |
| 249 | .SH NAME |
| 250 | Tcl_EvalObjEx, Tcl_EvalFile, Tcl_EvalObjv, Tcl_Eval, Tcl_EvalEx, Tcl_GlobalEval, Tcl_GlobalEvalObj, Tcl_VarEval, Tcl_VarEvalVA \- execute Tcl scripts |
| 251 | .SH SYNOPSIS |
| 252 | .nf |
| 253 | \fB#include <tcl.h>\fR |
| 254 | .sp |
| 255 | .VS |
| 256 | int |
| 257 | \fBTcl_EvalObjEx\fR(\fIinterp, objPtr, flags\fR) |
| 258 | .sp |
| 259 | int |
| 260 | \fBTcl_EvalFile\fR(\fIinterp, fileName\fR) |
| 261 | .sp |
| 262 | int |
| 263 | \fBTcl_EvalObjv\fR(\fIinterp, objc, objv, flags\fR) |
| 264 | .sp |
| 265 | int |
| 266 | \fBTcl_Eval\fR(\fIinterp, script\fR) |
| 267 | .sp |
| 268 | int |
| 269 | \fBTcl_EvalEx\fR(\fIinterp, script, numBytes, flags\fR) |
| 270 | .sp |
| 271 | int |
| 272 | \fBTcl_GlobalEval\fR(\fIinterp, script\fR) |
| 273 | .sp |
| 274 | int |
| 275 | \fBTcl_GlobalEvalObj\fR(\fIinterp, objPtr\fR) |
| 276 | .sp |
| 277 | int |
| 278 | \fBTcl_VarEval\fR(\fIinterp, string, string, ... \fB(char *) NULL\fR) |
| 279 | .sp |
| 280 | int |
| 281 | \fBTcl_VarEvalVA\fR(\fIinterp, argList\fR) |
| 282 | .SH ARGUMENTS |
| 283 | .AS Tcl_Interp **termPtr; |
| 284 | .AP Tcl_Interp *interp in |
| 285 | Interpreter in which to execute the script. The interpreter's result is |
| 286 | modified to hold the result or error message from the script. |
| 287 | .AP Tcl_Obj *objPtr in |
| 288 | A Tcl object containing the script to execute. |
| 289 | .AP int flags in |
| 290 | ORed combination of flag bits that specify additional options. |
| 291 | \fBTCL_EVAL_GLOBAL\fR and \fBTCL_EVAL_DIRECT\fR are currently supported. |
| 292 | .AP "CONST char" *fileName in |
| 293 | Name of a file containing a Tcl script. |
| 294 | .AP int objc in |
| 295 | The number of objects in the array pointed to by \fIobjPtr\fR; |
| 296 | this is also the number of words in the command. |
| 297 | .AP Tcl_Obj **objv in |
| 298 | Points to an array of pointers to objects; each object holds the |
| 299 | value of a single word in the command to execute. |
| 300 | .AP int numBytes in |
| 301 | The number of bytes in \fIscript\fR, not including any |
| 302 | null terminating character. If \-1, then all characters up to the |
| 303 | first null byte are used. |
| 304 | .AP "CONST char" *script in |
| 305 | Points to first byte of script to execute (null-terminated and UTF-8). |
| 306 | .AP char *string in |
| 307 | String forming part of a Tcl script. |
| 308 | .AP va_list argList in |
| 309 | An argument list which must have been initialised using |
| 310 | \fBTCL_VARARGS_START\fR, and cleared using \fBva_end\fR. |
| 311 | .BE |
| 312 | |
| 313 | .SH DESCRIPTION |
| 314 | .PP |
| 315 | The procedures described here are invoked to execute Tcl scripts in |
| 316 | various forms. |
| 317 | \fBTcl_EvalObjEx\fR is the core procedure and is used by many of the others. |
| 318 | It executes the commands in the script stored in \fIobjPtr\fR |
| 319 | until either an error occurs or the end of the script is reached. |
| 320 | If this is the first time \fIobjPtr\fR has been executed, |
| 321 | its commands are compiled into bytecode instructions |
| 322 | which are then executed. The |
| 323 | bytecodes are saved in \fIobjPtr\fR so that the compilation step |
| 324 | can be skipped if the object is evaluated again in the future. |
| 325 | .PP |
| 326 | The return value from \fBTcl_EvalObjEx\fR (and all the other procedures |
| 327 | described here) is a Tcl completion code with |
| 328 | one of the values \fBTCL_OK\fR, \fBTCL_ERROR\fR, \fBTCL_RETURN\fR, |
| 329 | \fBTCL_BREAK\fR, or \fBTCL_CONTINUE\fR, or possibly some other |
| 330 | integer value originating in an extension. |
| 331 | In addition, a result value or error message is left in \fIinterp\fR's |
| 332 | result; it can be retrieved using \fBTcl_GetObjResult\fR. |
| 333 | .PP |
| 334 | \fBTcl_EvalFile\fR reads the file given by \fIfileName\fR and evaluates |
| 335 | its contents as a Tcl script. It returns the same information as |
| 336 | \fBTcl_EvalObjEx\fR. |
| 337 | If the file couldn't be read then a Tcl error is returned to describe |
| 338 | why the file couldn't be read. |
| 339 | .VS 8.4 |
| 340 | The eofchar for files is '\\32' (^Z) for all platforms. |
| 341 | If you require a ``^Z'' in code for string comparison, you can use |
| 342 | ``\\032'' or ``\\u001a'', which will be safely substituted by the Tcl |
| 343 | interpreter into ``^Z''. |
| 344 | .VE 8.4 |
| 345 | .PP |
| 346 | \fBTcl_EvalObjv\fR executes a single pre-parsed command instead of a |
| 347 | script. The \fIobjc\fR and \fIobjv\fR arguments contain the values |
| 348 | of the words for the Tcl command, one word in each object in |
| 349 | \fIobjv\fR. \fBTcl_EvalObjv\fR evaluates the command and returns |
| 350 | a completion code and result just like \fBTcl_EvalObjEx\fR. |
| 351 | .PP |
| 352 | \fBTcl_Eval\fR is similar to \fBTcl_EvalObjEx\fR except that the script to |
| 353 | be executed is supplied as a string instead of an object and no compilation |
| 354 | occurs. The string should be a proper UTF-8 string as converted by |
| 355 | \fBTcl_ExternalToUtfDString\fR or \fBTcl_ExternalToUtf\fR when it is known |
| 356 | to possibly contain upper ASCII characters who's possible combinations |
| 357 | might be a UTF-8 special code. The string is parsed and executed directly |
| 358 | (using \fBTcl_EvalObjv\fR) instead of compiling it and executing the |
| 359 | bytecodes. In situations where it is known that the script will never be |
| 360 | executed again, \fBTcl_Eval\fR may be faster than \fBTcl_EvalObjEx\fR. |
| 361 | \fBTcl_Eval\fR returns a completion code and result just like |
| 362 | \fBTcl_EvalObjEx\fR. Note: for backward compatibility with versions before |
| 363 | Tcl 8.0, \fBTcl_Eval\fR copies the object result in \fIinterp\fR to |
| 364 | \fIinterp->result\fR (use is deprecated) where it can be accessed directly. |
| 365 | This makes \fBTcl_Eval\fR somewhat slower than \fBTcl_EvalEx\fR, which |
| 366 | doesn't do the copy. |
| 367 | .PP |
| 368 | \fBTcl_EvalEx\fR is an extended version of \fBTcl_Eval\fR that takes |
| 369 | additional arguments \fInumBytes\fR and \fIflags\fR. For the |
| 370 | efficiency reason given above, \fBTcl_EvalEx\fR is generally preferred |
| 371 | over \fBTcl_Eval\fR. |
| 372 | .PP |
| 373 | \fBTcl_GlobalEval\fR and \fBTcl_GlobalEvalObj\fR are older procedures |
| 374 | that are now deprecated. They are similar to \fBTcl_EvalEx\fR and |
| 375 | \fBTcl_EvalObjEx\fR except that the script is evaluated in the global |
| 376 | namespace and its variable context consists of global variables only |
| 377 | (it ignores any Tcl procedures that are active). These functions are |
| 378 | equivalent to using the \fBTCL_EVAL_GLOBAL\fR flag (see below). |
| 379 | .PP |
| 380 | \fBTcl_VarEval\fR takes any number of string arguments |
| 381 | of any length, concatenates them into a single string, |
| 382 | then calls \fBTcl_Eval\fR to execute that string as a Tcl command. |
| 383 | It returns the result of the command and also modifies |
| 384 | \fIinterp->result\fR in the same way as \fBTcl_Eval\fR. |
| 385 | The last argument to \fBTcl_VarEval\fR must be NULL to indicate the end |
| 386 | of arguments. \fBTcl_VarEval\fR is now deprecated. |
| 387 | .PP |
| 388 | \fBTcl_VarEvalVA\fR is the same as \fBTcl_VarEval\fR except that |
| 389 | instead of taking a variable number of arguments it takes an argument |
| 390 | list. Like \fBTcl_VarEval\fR, \fBTcl_VarEvalVA\fR is deprecated. |
| 391 | |
| 392 | .SH "FLAG BITS" |
| 393 | Any ORed combination of the following values may be used for the |
| 394 | \fIflags\fR argument to procedures such as \fBTcl_EvalObjEx\fR: |
| 395 | .TP 23 |
| 396 | \fBTCL_EVAL_DIRECT\fR |
| 397 | This flag is only used by \fBTcl_EvalObjEx\fR; it is ignored by |
| 398 | other procedures. If this flag bit is set, the script is not |
| 399 | compiled to bytecodes; instead it is executed directly |
| 400 | as is done by \fBTcl_EvalEx\fR. The |
| 401 | \fBTCL_EVAL_DIRECT\fR flag is useful in situations where the |
| 402 | contents of an object are going to change immediately, so the |
| 403 | bytecodes won't be reused in a future execution. In this case, |
| 404 | it's faster to execute the script directly. |
| 405 | .TP 23 |
| 406 | \fBTCL_EVAL_GLOBAL\fR |
| 407 | If this flag is set, the script is processed at global level. This |
| 408 | means that it is evaluated in the global namespace and its variable |
| 409 | context consists of global variables only (it ignores any Tcl |
| 410 | procedures at are active). |
| 411 | |
| 412 | .SH "MISCELLANEOUS DETAILS" |
| 413 | .PP |
| 414 | During the processing of a Tcl command it is legal to make nested |
| 415 | calls to evaluate other commands (this is how procedures and |
| 416 | some control structures are implemented). |
| 417 | If a code other than \fBTCL_OK\fR is returned |
| 418 | from a nested \fBTcl_EvalObjEx\fR invocation, |
| 419 | then the caller should normally return immediately, |
| 420 | passing that same return code back to its caller, |
| 421 | and so on until the top-level application is reached. |
| 422 | A few commands, like \fBfor\fR, will check for certain |
| 423 | return codes, like \fBTCL_BREAK\fR and \fBTCL_CONTINUE\fR, and process them |
| 424 | specially without returning. |
| 425 | .PP |
| 426 | \fBTcl_EvalObjEx\fR keeps track of how many nested \fBTcl_EvalObjEx\fR |
| 427 | invocations are in progress for \fIinterp\fR. |
| 428 | If a code of \fBTCL_RETURN\fR, \fBTCL_BREAK\fR, or \fBTCL_CONTINUE\fR is |
| 429 | about to be returned from the topmost \fBTcl_EvalObjEx\fR |
| 430 | invocation for \fIinterp\fR, |
| 431 | it converts the return code to \fBTCL_ERROR\fR |
| 432 | and sets \fIinterp\fR's result to an error message indicating that |
| 433 | the \fBreturn\fR, \fBbreak\fR, or \fBcontinue\fR command was |
| 434 | invoked in an inappropriate place. |
| 435 | This means that top-level applications should never see a return code |
| 436 | from \fBTcl_EvalObjEx\fR other then \fBTCL_OK\fR or \fBTCL_ERROR\fR. |
| 437 | .VE |
| 438 | |
| 439 | .SH KEYWORDS |
| 440 | execute, file, global, object, result, script |