'\"
'\" Copyright (c) 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: @(#) PkgRequire.3 1.4 96/02/15 20:03:16
'\" 
.so man.macros
.TH Tcl_PkgRequire 3 7.5 Tcl "Tcl Library Procedures"
.BS
.SH NAME
Tcl_PkgRequire, Tcl_PkgProvide \- package version control
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
char *
\fBTcl_PkgRequire\fR(\fIinterp, name, version, exact\fR)
.sp
int
\fBTcl_PkgProvide\fR(\fIinterp, name, version\fR)
.SH ARGUMENTS
.AS Tcl_FreeProc clientData
.AP Tcl_Interp *interp in
Interpreter where package is needed or available.
.AP char *name in
Name of package.
.AP char *version in
A version string consisting of one or more decimal numbers
separated by dots.
.AP int exact in
Non-zero means that only the particular version specified by
\fIversion\fR is acceptable.
Zero means that newer versions than \fIversion\fR are also
acceptable as long as they have the same major version number
as \fIversion\fR.
.BE

.SH DESCRIPTION
.PP
These procedures provide C-level interfaces to Tcl's package and
version management facilities.
\fBTcl_PkgRequire\fR is equivalent to the \fBpackage require\fR
command, and \fBTcl_PkgProvide\fR is equivalent to the
\fBpackage provide\fR command.
See the documentation for the Tcl commands for details on what these
procedures do.
If \fBTcl_PkgRequire\fR completes successfully it returns a pointer
to the version string for the version of the package that is provided
in the interpreter (which may be different than \fIversion\fR); if
an error occurs it returns NULL and leaves an error message in
\fIinterp->result\fR.
\fBTcl_PkgProvide\fR returns TCL_OK if it completes successfully;
if an error occurs it returns TCL_ERROR and leaves an error message
in \fIinterp->result\fR.

.SH KEYWORDS
package, provide, require, version