'\"
'\" 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.
'\"
.TH Tcl_PkgRequire 3tcl 7.5 Tcl "Tcl Library Procedures"
.\" The -*- nroff -*- definitions below are for supplemental macros used
.\" in Tcl/Tk manual entries.
.\"
.\" .AP type name in/out ?indent?
.\"	Start paragraph describing an argument to a library procedure.
.\"	type is type of argument (int, etc.), in/out is either "in", "out",
.\"	or "in/out" to describe whether procedure reads or modifies arg,
.\"	and indent is equivalent to second arg of .IP (shouldn't ever be
.\"	needed;  use .AS below instead)
.\"
.\" .AS ?type? ?name?
.\"	Give maximum sizes of arguments for setting tab stops.  Type and
.\"	name are examples of largest possible arguments that will be passed
.\"	to .AP later.  If args are omitted, default tab stops are used.
.\"
.\" .BS
.\"	Start box enclosure.  From here until next .BE, everything will be
.\"	enclosed in one large box.
.\"
.\" .BE
.\"	End of box enclosure.
.\"
.\" .CS
.\"	Begin code excerpt.
.\"
.\" .CE
.\"	End code excerpt.
.\"
.\" .VS ?version? ?br?
.\"	Begin vertical sidebar, for use in marking newly-changed parts
.\"	of man pages.  The first argument is ignored and used for recording
.\"	the version when the .VS was added, so that the sidebars can be
.\"	found and removed when they reach a certain age.  If another argument
.\"	is present, then a line break is forced before starting the sidebar.
.\"
.\" .VE
.\"	End of vertical sidebar.
.\"
.\" .DS
.\"	Begin an indented unfilled display.
.\"
.\" .DE
.\"	End of indented unfilled display.
.\"
.\" .SO ?manpage?
.\"	Start of list of standard options for a Tk widget. The manpage
.\"	argument defines where to look up the standard options; if
.\"	omitted, defaults to "options". The options follow on successive
.\"	lines, in three columns separated by tabs.
.\"
.\" .SE
.\"	End of list of standard options for a Tk widget.
.\"
.\" .OP cmdName dbName dbClass
.\"	Start of description of a specific option.  cmdName gives the
.\"	option's name as specified in the class command, dbName gives
.\"	the option's name in the option database, and dbClass gives
.\"	the option's class in the option database.
.\"
.\" .UL arg1 arg2
.\"	Print arg1 underlined, then print arg2 normally.
.\"
.\" .QW arg1 ?arg2?
.\"	Print arg1 in quotes, then arg2 normally (for trailing punctuation).
.\"
.\" .PQ arg1 ?arg2?
.\"	Print an open parenthesis, arg1 in quotes, then arg2 normally
.\"	(for trailing punctuation) and then a closing parenthesis.
.\"
.\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
.if t .wh -1.3i ^B
.nr ^l \n(.l
.ad b
.\"	# Start an argument description
.de AP
.ie !"\\$4"" .TP \\$4
.el \{\
.   ie !"\\$2"" .TP \\n()Cu
.   el          .TP 15
.\}
.ta \\n()Au \\n()Bu
.ie !"\\$3"" \{\
\&\\$1 \\fI\\$2\\fP (\\$3)
.\".b
.\}
.el \{\
.br
.ie !"\\$2"" \{\
\&\\$1	\\fI\\$2\\fP
.\}
.el \{\
\&\\fI\\$1\\fP
.\}
.\}
..
.\"	# define tabbing values for .AP
.de AS
.nr )A 10n
.if !"\\$1"" .nr )A \\w'\\$1'u+3n
.nr )B \\n()Au+15n
.\"
.if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
.nr )C \\n()Bu+\\w'(in/out)'u+2n
..
.AS Tcl_Interp Tcl_CreateInterp in/out
.\"	# BS - start boxed text
.\"	# ^y = starting y location
.\"	# ^b = 1
.de BS
.br
.mk ^y
.nr ^b 1u
.if n .nf
.if n .ti 0
.if n \l'\\n(.lu\(ul'
.if n .fi
..
.\"	# BE - end boxed text (draw box now)
.de BE
.nf
.ti 0
.mk ^t
.ie n \l'\\n(^lu\(ul'
.el \{\
.\"	Draw four-sided box normally, but don't draw top of
.\"	box if the box started on an earlier page.
.ie !\\n(^b-1 \{\
\h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.el \}\
\h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.\}
.fi
.br
.nr ^b 0
..
.\"	# VS - start vertical sidebar
.\"	# ^Y = starting y location
.\"	# ^v = 1 (for troff;  for nroff this doesn't matter)
.de VS
.if !"\\$2"" .br
.mk ^Y
.ie n 'mc \s12\(br\s0
.el .nr ^v 1u
..
.\"	# VE - end of vertical sidebar
.de VE
.ie n 'mc
.el \{\
.ev 2
.nf
.ti 0
.mk ^t
\h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
.sp -1
.fi
.ev
.\}
.nr ^v 0
..
.\"	# Special macro to handle page bottom:  finish off current
.\"	# box/sidebar if in box/sidebar mode, then invoked standard
.\"	# page bottom macro.
.de ^B
.ev 2
'ti 0
'nf
.mk ^t
.if \\n(^b \{\
.\"	Draw three-sided box if this is the box's first page,
.\"	draw two sides but no top otherwise.
.ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.\}
.if \\n(^v \{\
.nr ^x \\n(^tu+1v-\\n(^Yu
\kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
.\}
.bp
'fi
.ev
.if \\n(^b \{\
.mk ^y
.nr ^b 2
.\}
.if \\n(^v \{\
.mk ^Y
.\}
..
.\"	# DS - begin display
.de DS
.RS
.nf
.sp
..
.\"	# DE - end display
.de DE
.fi
.RE
.sp
..
.\"	# SO - start of list of standard options
.de SO
'ie '\\$1'' .ds So \\fBoptions\\fR
'el .ds So \\fB\\$1\\fR
.SH "STANDARD OPTIONS"
.LP
.nf
.ta 5.5c 11c
.ft B
..
.\"	# SE - end of list of standard options
.de SE
.fi
.ft R
.LP
See the \\*(So manual entry for details on the standard options.
..
.\"	# OP - start of full description for a single option
.de OP
.LP
.nf
.ta 4c
Command-Line Name:	\\fB\\$1\\fR
Database Name:	\\fB\\$2\\fR
Database Class:	\\fB\\$3\\fR
.fi
.IP
..
.\"	# CS - begin code excerpt
.de CS
.RS
.nf
.ta .25i .5i .75i 1i
..
.\"	# CE - end code excerpt
.de CE
.fi
.RE
..
.\"	# UL - underline word
.de UL
\\$1\l'|0\(ul'\\$2
..
.\"	# QW - apply quotation marks to word
.de QW
.ie '\\*(lq'"' ``\\$1''\\$2
.\"" fix emacs highlighting
.el \\*(lq\\$1\\*(rq\\$2
..
.\"	# PQ - apply parens and quotation marks to word
.de PQ
.ie '\\*(lq'"' (``\\$1''\\$2)\\$3
.\"" fix emacs highlighting
.el (\\*(lq\\$1\\*(rq\\$2)\\$3
..
.\"	# QR - quoted range
.de QR
.ie '\\*(lq'"' ``\\$1''\\-``\\$2''\\$3
.\"" fix emacs highlighting
.el \\*(lq\\$1\\*(rq\\-\\*(lq\\$2\\*(rq\\$3
..
.\"	# MT - "empty" string
.de MT
.QW ""
..
.BS
.SH NAME
Tcl_PkgRequire, Tcl_PkgRequireEx, Tcl_PkgRequireProc, Tcl_PkgPresent, Tcl_PkgPresentEx, Tcl_PkgProvide, Tcl_PkgProvideEx \- package version control
.SH SYNOPSIS
.nf
\fB#include <tcl.h>\fR
.sp
const char *
\fBTcl_PkgRequire\fR(\fIinterp, name, version, exact\fR)
.sp
const char *
\fBTcl_PkgRequireEx\fR(\fIinterp, name, version, exact, clientDataPtr\fR)
.sp
int
\fBTcl_PkgRequireProc\fR(\fIinterp, name, objc, objv, clientDataPtr\fR)
.sp
const char *
\fBTcl_PkgPresent\fR(\fIinterp, name, version, exact\fR)
.sp
const char *
\fBTcl_PkgPresentEx\fR(\fIinterp, name, version, exact, clientDataPtr\fR)
.sp
int
\fBTcl_PkgProvide\fR(\fIinterp, name, version\fR)
.sp
int
\fBTcl_PkgProvideEx\fR(\fIinterp, name, version, clientData\fR)
.SH ARGUMENTS
.AS void *clientDataPtr out
.AP Tcl_Interp *interp in
Interpreter where package is needed or available.
.AP "const char" *name in
Name of package.
.AP "const 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.
.AP "const void" *clientData in
Arbitrary value to be associated with the package.
.AP void *clientDataPtr out
Pointer to place to store the value associated with the matching
package. It is only changed if the pointer is not NULL and the
function completed successfully. The storage can be any pointer
type with the same size as a void pointer.
.AP Tcl_Size objc in
Number of requirements.
.AP Tcl_Obj* objv[] in
Array of requirements.
.BE
.SH DESCRIPTION
.PP
These procedures provide C-level interfaces to Tcl's package and
version management facilities.
.PP
\fBTcl_PkgRequire\fR is equivalent to the \fBpackage require\fR
command, \fBTcl_PkgPresent\fR is equivalent to the \fBpackage present\fR
command, and \fBTcl_PkgProvide\fR is equivalent to the
\fBpackage provide\fR command.
.PP
See the documentation for the Tcl commands for details on what these
procedures do.
.PP
If \fBTcl_PkgPresent\fR or \fBTcl_PkgRequire\fR complete successfully
they return 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 they return NULL and leave an error
message in the interpreter's result.
.PP
\fBTcl_PkgProvide\fR returns \fBTCL_OK\fR if it completes successfully;
if an error occurs it returns \fBTCL_ERROR\fR and leaves an error message
in the interpreter's result.
.PP
\fBTcl_PkgProvideEx\fR, \fBTcl_PkgPresentEx\fR and \fBTcl_PkgRequireEx\fR
allow the setting and retrieving of the client data associated with
the package. In all other respects they are equivalent to the matching
functions.
.PP
\fBTcl_PkgRequireProc\fR is the form of \fBpackage require\fR handling
multiple requirements. The other forms are present for backward
compatibility and translate their invocations to this form.
.SH "REFERENCE COUNT MANAGEMENT"
.PP
The requirements values given (in the \fIobjv\fR argument) to
\fBTcl_PkgRequireProc\fR must have non-zero reference counts.
.SH KEYWORDS
package, present, provide, require, version
.SH "SEE ALSO"
package(3tcl), Tcl_StaticLibrary(3tcl)