39 lines
1.3 KiB
Plaintext
39 lines
1.3 KiB
Plaintext
|
'\"
|
||
|
|
'\" Copyright (c) 1995-1996 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: @(#) vwait.n 1.3 96/03/25 20:27:21
|
||
|
|
'\"
|
||
|
|
.so man.macros
|
||
|
|
.TH vwait n 7.5 Tcl "Tcl Built-In Commands"
|
||
|
|
.BS
|
||
|
|
'\" Note: do not modify the .SH NAME line immediately below!
|
||
|
|
.SH NAME
|
||
|
|
vwait \- Process events until a variable is written
|
||
|
|
.SH SYNOPSIS
|
||
|
|
\fBvwait\fR ?\fIvarName\fR?
|
||
|
|
.BE
|
||
|
|
|
||
|
|
.SH DESCRIPTION
|
||
|
|
.PP
|
||
|
|
This command enters the Tcl event loop to process events, blocking
|
||
|
|
the application if no events are ready. It continues processing
|
||
|
|
events until some event handler sets the value of variable
|
||
|
|
\fIvarName\fR. Once \fIvarName\fR has been set, the \fBvwait\fR
|
||
|
|
command will return as soon as the event handler that modified
|
||
|
|
\fIvarName\fR completes.
|
||
|
|
.PP
|
||
|
|
In some cases the \fBvwait\fR command may not return immediately
|
||
|
|
after \fIvarName\fR is set. This can happen if the event handler
|
||
|
|
that sets \fIvarName\fR does not complete immediately. For example,
|
||
|
|
if an event handler sets \fIvarName\fR and then itself calls
|
||
|
|
\fBvwait\fR to wait for a different variable, then it may not return
|
||
|
|
for a long time. During this time the top-level \fBvwait\fR is
|
||
|
|
blocked waiting for the event handler to complete, so it cannot
|
||
|
|
return either.
|
||
|
|
|
||
|
|
.SH KEYWORDS
|
||
|
|
event, variable, wait
|