77 lines
2.8 KiB
Groff
77 lines
2.8 KiB
Groff
'\"
|
|
'\" Copyright (c) 1994 The Regents of the University of California.
|
|
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
|
|
'\"
|
|
'\" See the file "license.terms" for information on usage and redistribution
|
|
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
|
|
'\"
|
|
'\" SCCS: @(#) UpVar.3 1.6 96/03/25 20:09:19
|
|
'\"
|
|
.so man.macros
|
|
.TH Tcl_UpVar 3 7.4 Tcl "Tcl Library Procedures"
|
|
.BS
|
|
.SH NAME
|
|
Tcl_UpVar, Tcl_UpVar2 \- link one variable to another
|
|
.SH SYNOPSIS
|
|
.nf
|
|
\fB#include <tcl.h>\fR
|
|
.sp
|
|
int
|
|
\fBTcl_UpVar(\fIinterp, frameName, sourceName, destName, flags\fB)\fR
|
|
.sp
|
|
int
|
|
\fBTcl_UpVar2(\fIinterp, frameName, name1, name2, destName, flags\fB)\fR
|
|
.SH ARGUMENTS
|
|
.AS Tcl_VarTraceProc prevClientData
|
|
.AP Tcl_Interp *interp in
|
|
Interpreter containing variables; also used for error reporting.
|
|
.AP char *frameName in
|
|
Identifies the stack frame containing source variable.
|
|
May have any of the forms accepted by
|
|
the \fBupvar\fR command, such as \fB#0\fR or \fB1\fR.
|
|
.AP char *sourceName in
|
|
Name of source variable, in the frame given by \fIframeName\fR.
|
|
May refer to a scalar variable or to an array variable with a
|
|
parenthesized index.
|
|
.AP char *destName in
|
|
Name of destination variable, which is to be linked to source
|
|
variable so that references to \fIdestName\fR
|
|
refer to the other variable. Must not currently exist except as
|
|
an upvar-ed variable.
|
|
.AP int flags in
|
|
Either TCL_GLOBAL_ONLY or 0; if non-zero, then \fIdestName\fR is
|
|
a global variable; otherwise it is a local to the current procedure
|
|
(or global if no procedure is active).
|
|
.AP char *name1 in
|
|
First part of source variable's name (scalar name, or name of array
|
|
without array index).
|
|
.AP char *name2 in
|
|
If source variable is an element of an array, gives the index of the element.
|
|
For scalar source variables, is NULL.
|
|
.BE
|
|
|
|
.SH DESCRIPTION
|
|
.PP
|
|
\fBTcl_UpVar\fR and \fBTcl_UpVar2\fR provide the same functionality
|
|
as the \fBupvar\fR command: they make a link from a source variable
|
|
to a destination variable, so that references to the destination are
|
|
passed transparently through to the source.
|
|
The name of the source variable may be specified either as a single
|
|
string such as \fBxyx\fR or \fBa(24)\fR (by calling \fBTcl_UpVar\fR)
|
|
or in two parts where the array name has been separated from the
|
|
element name (by calling \fBTcl_UpVar2\fR).
|
|
The destination variable name is specified in a single string; it
|
|
may not be an array element.
|
|
.PP
|
|
Both procedures return either TCL_OK or TCL_ERROR, and they
|
|
leave an error message in \fIinterp->result\fR if an error
|
|
occurs.
|
|
.PP
|
|
As with the \fBupvar\fR command, the source variable need not exist;
|
|
if it does exist, unsetting it later does not destroy the link. The
|
|
destination variable may exist at the time of the call, but if so
|
|
it must exist as a linked variable.
|
|
|
|
.SH KEYWORDS
|
|
linked variable, upvar, variable
|