--- /dev/null
+'\"
+'\" Copyright (c) 1989-1993 The Regents of the University of California.
+'\" Copyright (c) 1994-1997 Sun Microsystems, Inc.
+'\" Copyright (c) 2000 Scriptics Corporation.
+'\"
+'\" See the file "license.terms" for information on usage and redistribution
+'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+'\"
+'\" RCS: @(#) $Id$
+'\"
+.so man.macros
+.TH Tcl_Eval 3 8.1 Tcl "Tcl Library Procedures"
+.BS
+.SH NAME
+Tcl_EvalObjEx, Tcl_EvalFile, Tcl_EvalObjv, Tcl_Eval, Tcl_EvalEx, Tcl_GlobalEval, Tcl_GlobalEvalObj, Tcl_VarEval, Tcl_VarEvalVA \- execute Tcl scripts
+.SH SYNOPSIS
+.nf
+\fB#include <tcl.h>\fR
+.sp
+.VS
+int
+\fBTcl_EvalObjEx\fR(\fIinterp, objPtr, flags\fR)
+.sp
+int
+\fBTcl_EvalFile\fR(\fIinterp, fileName\fR)
+.sp
+int
+\fBTcl_EvalObjv\fR(\fIinterp, objc, objv, flags\fR)
+.sp
+int
+\fBTcl_Eval\fR(\fIinterp, script\fR)
+.sp
+int
+\fBTcl_EvalEx\fR(\fIinterp, script, numBytes, flags\fR)
+.sp
+int
+\fBTcl_GlobalEval\fR(\fIinterp, script\fR)
+.sp
+int
+\fBTcl_GlobalEvalObj\fR(\fIinterp, objPtr, flags\fR)
+.sp
+int
+\fBTcl_VarEval\fR(\fIinterp, string, string, ... \fB(char *) NULL\fR)
+.sp
+int
+\fBTcl_VarEvalVA\fR(\fIinterp, argList\fR)
+.SH ARGUMENTS
+.AS Tcl_Interp **termPtr;
+.AP Tcl_Interp *interp in
+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.
+.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;
+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
+value of a single word in the command to execute.
+.AP int numBytes in
+The number of bytes in \fIscript\fR, not including any
+null terminating character. If \-1, then all characters up to the
+first null byte are used.
+.AP "CONST char" *script in
+Points to first byte of script to execute (NULL terminated and UTF-8).
+.AP char *string in
+String forming part of a Tcl script.
+.AP va_list argList in
+An argument list which must have been initialised using
+\fBTCL_VARARGS_START\fR, and cleared using \fBva_end\fR.
+.BE
+
+.SH DESCRIPTION
+.PP
+The procedures described here are invoked to execute Tcl scripts in
+various forms.
+\fBTcl_EvalObjEx\fR is the core procedure and is used by many of the others.
+It executes the commands in the script stored in \fIobjPtr\fR
+until either an error occurs or the end of the script is reached.
+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.
+.PP
+The return value from \fBTcl_EvalObjEx\fR (and all the other procedures
+described here) is a Tcl completion code with
+one of the values \fBTCL_OK\fR, \fBTCL_ERROR\fR, \fBTCL_RETURN\fR,
+\fBTCL_BREAK\fR, or \fBTCL_CONTINUE\fR.
+In addition, a result value or error message is left in \fIinterp\fR's
+result; it can be retrieved using \fBTcl_GetObjResult\fR.
+.PP
+\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.
+.VS 8.4
+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''.
+.VE 8.4
+.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
+\fIobjv\fR. \fBTcl_EvalObjv\fR evaluates the command and returns
+a completion code and result just like \fBTcl_EvalObjEx\fR.
+.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
+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 who's possible combinations
+might be a UTF-8 special code. The string is parsed and executed directly
+(using \fBTcl_EvalObjv\fR) instead of compiling it and executing the
+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
+\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.
+.PP
+\fBTcl_EvalEx\fR is an extended version of \fBTcl_Eval\fR that takes
+additional arguments \fInumBytes\fR and \fIflags\fR. For the
+efficiency reason given above, \fBTcl_EvalEx\fR is generally preferred
+over \fBTcl_Eval\fR.
+.PP
+\fBTcl_GlobalEval\fR and \fBTcl_GlobalEvalObj\fR are older procedures
+that are now deprecated. They are similar to \fBTcl_EvalEx\fR and
+\fBTcl_EvalObjEx\fR except that the script is evaluated in the global
+namespace and its variable context consists of global variables only
+(it ignores any Tcl procedures that are active). These functions are
+equivalent to using the \fBTCL_EVAL_GLOBAL\fR flag (see below).
+.PP
+\fBTcl_VarEval\fR takes any number of string arguments
+of any length, concatenates them into a single string,
+then calls \fBTcl_Eval\fR to execute that string as a Tcl command.
+It returns the result of the command and also modifies
+\fIinterp->result\fR in the same way as \fBTcl_Eval\fR.
+The last argument to \fBTcl_VarEval\fR must be NULL to indicate the end
+of arguments. \fBTcl_VarEval\fR is now deprecated.
+.PP
+\fBTcl_VarEvalVA\fR is the same as \fBTcl_VarEval\fR except that
+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"
+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.
+.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).
+
+.SH "MISCELLANEOUS DETAILS"
+.PP
+During the processing of a Tcl command it is legal to make nested
+calls to evaluate other commands (this is how procedures and
+some control structures are implemented).
+If a code other than \fBTCL_OK\fR is returned
+from a nested \fBTcl_EvalObjEx\fR invocation,
+then the caller should normally return immediately,
+passing that same return code back to its caller,
+and so on until the top-level application is reached.
+A few commands, like \fBfor\fR, will check for certain
+return codes, like \fBTCL_BREAK\fR and \fBTCL_CONTINUE\fR, and process them
+specially without returning.
+.PP
+\fBTcl_EvalObjEx\fR keeps track of how many nested \fBTcl_EvalObjEx\fR
+invocations are in progress for \fIinterp\fR.
+If a code of \fBTCL_RETURN\fR, \fBTCL_BREAK\fR, or \fBTCL_CONTINUE\fR is
+about to be returned from the topmost \fBTcl_EvalObjEx\fR
+invocation for \fIinterp\fR,
+it converts the return code to \fBTCL_ERROR\fR
+and sets \fIinterp\fR's result to an error message indicating that
+the \fBreturn\fR, \fBbreak\fR, or \fBcontinue\fR command was
+invoked in an inappropriate place.
+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.
+.VE
+
+.SH KEYWORDS
+execute, file, global, object, result, script
OSDN Git Service
