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'\"
'\" 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: eval.n,v 1.4.2.1 2004/10/27 09:35:38 dkf Exp $
'\"
.so man.macros
.TH eval n "" Tcl "Tcl Built-In Commands"
.BS
'\" Note: do not modify the .SH NAME line immediately below!
.SH NAME
eval \- Evaluate a Tcl script
.SH SYNOPSIS
\fBeval \fIarg \fR?\fIarg ...\fR?
.BE
.SH DESCRIPTION
.PP
\fBEval\fR takes one or more arguments, which together comprise a Tcl
script containing one or more commands.
\fBEval\fR concatenates all its arguments in the same
fashion as the \fBconcat\fR command, passes the concatenated string to the
Tcl interpreter recursively, and returns the result of that
evaluation (or any error generated by it).
Note that the \fBlist\fR command quotes sequences of words in such a
way that they are not further expanded by the \fBeval\fR command.
.SH EXAMPLE
This procedure acts in a way that is analogous to the \fBlappend\fR
command, except it inserts the argument values at the start of the
list in the variable:
.CS
proc lprepend {varName args} {
upvar 1 $varName var
# Ensure that the variable exists and contains a list
lappend var
# Now we insert all the arguments in one go
set var [\fBeval\fR [list linsert $var 0] $args]
}
.CE
.SH KEYWORDS
concatenate, evaluate, script
.SH "SEE ALSO"
catch(n), concat(n), error(n), list(n), subst(n), tclvars(n)
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