archie/tcl7.6/doc/Concat.3

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'\" SCCS: @(#) Concat.3 1.11 96/06/05 18:00:12
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.so man.macros
.TH Tcl_Concat 3 7.5 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_Concat \- concatenate a collection of strings
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
char *
\fBTcl_Concat\fR(\fIargc, argv\fR)
.SH ARGUMENTS
.AP int argc in
Number of strings.
.AP char *argv[] in
Array of strings to concatenate.  Must have \fIargc\fR entries.
.BE

.SH DESCRIPTION
.PP
\fBTcl_Concat\fR is a utility procedure used by several of the
Tcl commands.  Given a collection of strings, it concatenates
them together into a single string, with the original strings
separated by spaces.  This procedure behaves differently than
\fBTcl_Merge\fR, in that the arguments are simply concatenated:
no effort is made to ensure proper list structure.
However, in most common usage the arguments will all be proper
lists themselves;  if this is true, then the result will also have
proper list structure.
.PP
\fBTcl_Concat\fR eliminates leading and trailing white space as it
copies strings from \fBargv\fR to the result.  If an element of
\fBargv\fR consists of nothing but white space, then that string
is ignored entirely.  This white-space removal was added to make
the output of the \fBconcat\fR command cleaner-looking.
.PP
.VS
The result string is dynamically allocated
using \fBTcl_Alloc\fR;  the caller must eventually release the space
by calling \fBTcl_Free\fR.
.VE

.SH KEYWORDS
concatenate, strings