'\"
'\" Copyright (c) 1993 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.
'\" 
'\" RCS: @(#) Id
'\" 
.so man.macros
.TH set n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
set \- Read and write variables
.SH SYNOPSIS
\fBset \fIvarName \fR?\fIvalue\fR?
.BE

.SH DESCRIPTION
.PP
Returns the value of variable \fIvarName\fR.
If \fIvalue\fR is specified, then set
the value of \fIvarName\fR to \fIvalue\fR, creating a new variable
if one doesn't already exist, and return its value.
If \fIvarName\fR contains an open parenthesis and ends with a
close parenthesis, then it refers to an array element:  the characters
before the first open parenthesis are the name of the array,
and the characters between the parentheses are the index within the array.
Otherwise \fIvarName\fR refers to a scalar variable.
Normally, \fIvarName\fR is unqualified
(does not include the names of any containing namespaces),
and the variable of that name in the current namespace is read or written.
If \fIvarName\fR includes namespace qualifiers
(in the array name if it refers to an array element),
the variable in the specified namespace is read or written.
.PP
If no procedure is active,
then \fIvarName\fR refers to a namespace variable
(global variable if the current namespace is the global namespace).
If a procedure is active, then \fIvarName\fR refers to a parameter
or local variable of the procedure unless the \fBglobal\fR command
was invoked to declare \fIvarName\fR to be global,
or unless a \fBvariable\fR command
was invoked to declare \fIvarName\fR to be a namespace variable.

.SH "SEE ALSO"
expr(n), proc(n), trace(n), unset(n)

.SH KEYWORDS
read, write, variable
