diff options
Diffstat (limited to 'doc/Eval.3')
| -rw-r--r-- | doc/Eval.3 | 56 |
1 files changed, 33 insertions, 23 deletions
@@ -6,10 +6,8 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: Eval.3,v 1.21 2005/05/10 18:33:55 kennykb Exp $ -'\" -.so man.macros .TH Tcl_Eval 3 8.1 Tcl "Tcl Library Procedures" +.so man.macros .BS .SH NAME Tcl_EvalObjEx, Tcl_EvalFile, Tcl_EvalObjv, Tcl_Eval, Tcl_EvalEx, Tcl_GlobalEval, Tcl_GlobalEvalObj, Tcl_VarEval, Tcl_VarEvalVA \- execute Tcl scripts @@ -49,17 +47,17 @@ int Interpreter in which to execute the script. The interpreter's result is modified to hold the result or error message from the script. .AP Tcl_Obj *objPtr in -A Tcl object containing the script to execute. +A Tcl value containing the script to execute. .AP int flags in ORed combination of flag bits that specify additional options. \fBTCL_EVAL_GLOBAL\fR and \fBTCL_EVAL_DIRECT\fR are currently supported. .AP "const char" *fileName in Name of a file containing a Tcl script. .AP int objc in -The number of objects in the array pointed to by \fIobjPtr\fR; +The number of values in the array pointed to by \fIobjPtr\fR; this is also the number of words in the command. .AP Tcl_Obj **objv in -Points to an array of pointers to objects; each object holds the +Points to an array of pointers to values; each value holds the value of a single word in the command to execute. .AP int numBytes in The number of bytes in \fIscript\fR, not including any @@ -71,7 +69,7 @@ Points to first byte of script to execute (null-terminated and UTF-8). String forming part of a Tcl script. .AP va_list argList in An argument list which must have been initialized using -\fBTCL_VARARGS_START\fR, and cleared using \fBva_end\fR. +\fBva_start\fR, and cleared using \fBva_end\fR. .BE .SH DESCRIPTION @@ -85,7 +83,7 @@ If this is the first time \fIobjPtr\fR has been executed, its commands are compiled into bytecode instructions which are then executed. The bytecodes are saved in \fIobjPtr\fR so that the compilation step -can be skipped if the object is evaluated again in the future. +can be skipped if the value is evaluated again in the future. .PP The return value from \fBTcl_EvalObjEx\fR (and all the other procedures described here) is a Tcl completion code with @@ -98,21 +96,30 @@ result; it can be retrieved using \fBTcl_GetObjResult\fR. \fBTcl_EvalFile\fR reads the file given by \fIfileName\fR and evaluates its contents as a Tcl script. It returns the same information as \fBTcl_EvalObjEx\fR. -If the file couldn't be read then a Tcl error is returned to describe -why the file couldn't be read. -The eofchar for files is '\\32' (^Z) for all platforms. -If you require a ``^Z'' in code for string comparison, you can use -``\\032'' or ``\\u001a'', which will be safely substituted by the Tcl -interpreter into ``^Z''. +If the file could not be read then a Tcl error is returned to describe +why the file could not be read. +The eofchar for files is +.QW \e32 +(^Z) for all platforms. If you require a +.QW ^Z +in code for string comparison, you can use +.QW \e032 +or +.QW \eu001a , +which will be safely substituted by the Tcl interpreter into +.QW ^Z . .PP \fBTcl_EvalObjv\fR executes a single pre-parsed command instead of a script. The \fIobjc\fR and \fIobjv\fR arguments contain the values -of the words for the Tcl command, one word in each object in +of the words for the Tcl command, one word in each value in \fIobjv\fR. \fBTcl_EvalObjv\fR evaluates the command and returns a completion code and result just like \fBTcl_EvalObjEx\fR. +The caller of \fBTcl_EvalObjv\fR has to manage the reference count of the +elements of \fIobjv\fR, insuring that the values are valid until +\fBTcl_EvalObjv\fR returns. .PP \fBTcl_Eval\fR is similar to \fBTcl_EvalObjEx\fR except that the script to -be executed is supplied as a string instead of an object and no compilation +be executed is supplied as a string instead of a value and no compilation occurs. The string should be a proper UTF-8 string as converted by \fBTcl_ExternalToUtfDString\fR or \fBTcl_ExternalToUtf\fR when it is known to possibly contain upper ASCII characters whose possible combinations @@ -122,10 +129,10 @@ bytecodes. In situations where it is known that the script will never be executed again, \fBTcl_Eval\fR may be faster than \fBTcl_EvalObjEx\fR. \fBTcl_Eval\fR returns a completion code and result just like \fBTcl_EvalObjEx\fR. Note: for backward compatibility with versions before -Tcl 8.0, \fBTcl_Eval\fR copies the object result in \fIinterp\fR to +Tcl 8.0, \fBTcl_Eval\fR copies the value result in \fIinterp\fR to \fIinterp->result\fR (use is deprecated) where it can be accessed directly. This makes \fBTcl_Eval\fR somewhat slower than \fBTcl_EvalEx\fR, which -doesn't do the copy. +does not do the copy. .PP \fBTcl_EvalEx\fR is an extended version of \fBTcl_Eval\fR that takes additional arguments \fInumBytes\fR and \fIflags\fR. For the @@ -152,24 +159,27 @@ instead of taking a variable number of arguments it takes an argument list. Like \fBTcl_VarEval\fR, \fBTcl_VarEvalVA\fR is deprecated. .SH "FLAG BITS" +.PP Any ORed combination of the following values may be used for the \fIflags\fR argument to procedures such as \fBTcl_EvalObjEx\fR: .TP 23 \fBTCL_EVAL_DIRECT\fR +. This flag is only used by \fBTcl_EvalObjEx\fR; it is ignored by other procedures. If this flag bit is set, the script is not compiled to bytecodes; instead it is executed directly as is done by \fBTcl_EvalEx\fR. The \fBTCL_EVAL_DIRECT\fR flag is useful in situations where the -contents of an object are going to change immediately, so the -bytecodes won't be reused in a future execution. In this case, -it's faster to execute the script directly. +contents of a value are going to change immediately, so the +bytecodes will not be reused in a future execution. In this case, +it is faster to execute the script directly. .TP 23 \fBTCL_EVAL_GLOBAL\fR +. If this flag is set, the script is processed at global level. This means that it is evaluated in the global namespace and its variable context consists of global variables only (it ignores any Tcl -procedures at are active). +procedures that are active). .SH "MISCELLANEOUS DETAILS" .PP @@ -198,4 +208,4 @@ This means that top-level applications should never see a return code from \fBTcl_EvalObjEx\fR other then \fBTCL_OK\fR or \fBTCL_ERROR\fR. .SH KEYWORDS -execute, file, global, object, result, script +execute, file, global, result, script, value |