pkg-config(1)							   User Commands						     pkg-config(1)

NAME

       pkg-config - return meta information about installed libraries

SYNOPSIS

       pkg-config  [--modversion] [--help] [--print-errors] [--silence-errors] [--cflags] [--libs] [--libs-only-L] [--libs-only-l] [--cflags-only-
       I]  [--variable=variable_name]  [--define-variable=variable_name=variable_value]  [--uninstalled]  [--exists]   [--atleast-version=version]
       [--exact-version=version] [--max-version=version] [libraries]

DESCRIPTION

       pkg-config  retrieves  information about installed libraries in the system. pkg-config is typically used to compile and link against one or
       more libraries. The following example shows how to use pkg-config in a Makefile:

       program: program.c
	     cc program.c `pkg-config --cflags --libs gnomeui`

       pkg-config retrieves information about packages from special metadata files. These files have the same name as the package, with the exten-
       sion  .pc.  By default, pkg-config looks in the directory /usr/lib/pkgconfig for these files. It also looks in the colon-separated (on Win-
       dows, semicolon-separated) list of directories specified by the PKG_CONFIG_PATH environment variable.

       The package name specified on the pkg-config command line is defined to be the name of the metadata file, without the .pc extension.  If  a
       library	can  install multiple versions simultaneously, it must give each version its own name. For example, GTK 1.2 might have the package
       name gtk+ while GTK 2.0 has the package name gtk+-2.0.

EXTENDED DESCRIPTION

       A .pc file has two kinds of line:

	 o  Keyword lines start with a keyword and a colon.

	 o  Variable definitions start with an alphanumeric string and an equals sign.

       Keywords are defined in advance and have special meaning to pkg-config.	Variables do not have special meaning, you can specify	any  vari-
       ables that you wish. However, users may expect to retrieve the usual directory name variables.

       Note that variable references are written "${foo}"; you can escape literal "${" as "$${".

       pkg-config supports the following keywords:

       Name		       A human-readable name for the package. Note that it is not the name passed as an argument to pkg-config.

       Description	       A brief description of the package.

       Version		       The most-specific-possible package version string.

       Requires 	       A  comma-separated list of packages that are required by your package. Flags from dependent packages will be merged
			       in to the flags reported for your package. Optionally, you can specify the version of the required  package  (using
			       the operators =, <, >, >=, <=). Specifying a version allows pkg-config to perform extra sanity checks. You may only
			       mention the same package once on the Requires: line. If the version of a package is not specified, any version will
			       be used with no checking.

       Conflicts	       Optional.   Allows  pkg-config  to perform additional sanity checks, primarily to detect broken user installations.
			       The syntax is the same as Requires: except that you can list the same package more than once, for example "foobar =
			       1.2.3,  foobar  =  1.2.5,  foobar >= 1.3", if you have reason to do so. If a version is not specified, your package
			       conflicts with all versions of the mentioned package. If a user tries to use your package and a conflicting package
			       at the same time, pkg-config complains.

       Libs		       The link flags specific to your package. Do not add any flags for required packages, pkg-config adds these automat-
			       ically.

       Cflags		       The compile flags specific to your package. Do not add any flags for required packages, pkg-config adds these auto-
			       matically.

       See the EXAMPLES section below for a sample .pc file.

   Windows Specialities
       If  a  .pc  file is found in a directory that ends with /lib/pkgconfig, the prefix for that package is assumed to be the grandparent of the
       directory in which the file was found, and the prefix variable is overridden for that file accordingly.

       In addition to the PKG_CONFIG_PATH  environment	variable,  the	Registry  keys	HKEY_CURRENT_USERSoftwarepkg-configPKG_CONFIG_PATH  and
       HKEY_LOCAL_MACHINESoftwarepkg-configPKG_CONFIG_PATH  can  be	used  to specify directories to search for .pc files. Each string value in
       these keys is treated as a directory in which to search for .pc files.

   autoconf Macros
       PKG_CHECK_MODULES(variablebase,modulelist[,action-if-found,[action-if-not-found]])

       The macro PKG_CHECK_MODULES can be used in configure.in to check whether modules exist, as shown in the following example:

       PKG_CHECK_MODULES(MYSTUFF, gtk+-2.0 >= 1.3.5 libxml = 1.8.4)

       In this example, the MYSTUFF_LIBS and MYSTUFF_CFLAGS substitution variables are set to the libs and cflags  values  for	the  given  module
       list. If a module is missing or has the wrong version, by default configure will abort with a message. To replace the default action, spec-
       ify an ACTION-IF-NOT-FOUND.  PKG_CHECK_MODULES will not print any error messages if you specify your own ACTION-IF-NOT-FOUND.  However,	it
       will set the variable MYSTUFF_PKG_ERRORS, which you can use to find out what went wrong.

   Compiling 64-Bit Binaries
       To  compile  64-bit binaries, pkg-config must use metadata files that specify the flags for the 64-bit libraries. To ensure that pkg-config
       can find the metadata files for 64-bit libraries, set the PKG_CONFIG_PATH environment variable  to  /usr/lib/64/pkgconfig/  when  compiling
       64-bit software.

OPTIONS

       The following options are supported:

       --atleast-version=version

	   See the entry for the --exists option.

       --cflags

	   Prints  pre-processor  and  compile flags required to compile the packages on the command line, including flags for all their dependen-
	   cies. Flags are "compressed" so that each identical flag appears only once. pkg-config exits with a nonzero	code  if  it  cannot  find
	   metadata for one or more of the packages on the command line.

       --define-variable=variablename=variablevalue

	   Sets a global value for a variable, overriding the value in any example. For example:

	   $ pkg-config --print-errors --define-variable=prefix=/foo 
	    --variable=prefix glib-2.0 /foo

       --dont-define-prefix

	   Available  only  on	Windows. This option prevents pkg-config from automatically trying to override the value of the variable prefix in
	   each .pc file.

       --errors-to-stdout

	   If printing errors, print them to stdout rather than the default stderr.

       --exact-version=version

	   See the entry for the --exists option.

       --exists

	   The --exists, --atleast-version=version, --exact-version=version, and --max-version=version options test whether the  packages  on  the
	   command  line are known to pkg-config, and optionally whether the version number of a package meets certain contraints. If all packages
	   exist and meet the specified version constraints, pkg-config exits successfully.  Otherwise, pkg-config  exits  unsuccessfully.  Rather
	   than  using the version-test options, you can simply give a version constraint after each package name, as shown in the following exam-
	   ple:

	   $ pkg-config --exists 'glib-2.0 >= 1.3.4 libxml = 1.8.3'

	   Remember to use the --print-errors option if you want to display error messages.

       --help

	    Displays a help message and terminates.

       --libs

	   Identical to --cflags option but only prints the link flags. Duplicate flags are merged, maintaining proper	ordering,  and	flags  for
	   dependencies are included in the output.

       --libs-only-L

	   Prints  the	-L/-R  part of the --libs option. That is, it defines the library search path but does not specify which libraries to link
	   with.

       --libs-only-l

	   Prints the -l part of the --libs option for the libraries specified on the command line. Note that the union of the	--libs-only-l  and
	   --libs-only-L options may be smaller than the --libs option, due to flags such as -rdynamic.

       --max-version=version

	   See the entry for the --exists option.

       --modversion

	   Requests  that  the	version information of the libraries specified on the command line be displayed. If pkg-config can find all of the
	   libraries on the command line, each library's version string is printed to stdout, one version per line. In this case pkg-config  exits
	   successfully. If one or more libraries is unknown, pkg-config exits with a nonzero code, and the contents of stdout are undefined.

       --msvc-syntax

	   Available  only  on Windows. This option causes pkg-config to output -l and -L flags in the form recognized by the Microsoft Visual C++
	   command-line compiler, cl, as follows:

	     o	Prints /libpath:x/some/path instead of -Lx:/some/path

	     o	Prints foo.lib instead of -lfoo

	   Note that the --libs output consists of flags for the linker, and should be placed on the cl command line after a /link switch.

       --prefix-variable=prefix

	   Available only on Windows. This option sets the name of the variable that pkg-config automatically sets as described above.

       --print-errors

	   Displays an error if one or more of the modules on the command line, or their dependencies, are not found, or if  an  error	occurs	in
	   parsing.  This  option  can be used alone to just print errors encountered locating modules on the command line, or with other options.
	   The PKG_CONFIG_DEBUG_SPEW environment variable overrides this option.

       --silence-errors

	   Does not display an error if one or more of the modules on the command line, or their dependencies, are  not  found,  or  if  an  error
	   occurs  in parsing. With predicate options such as --exists, pkg-config runs silently by default, because it is usually used in scripts
	   that want to control what is output. This option is only useful with options that print errors by default, such as --cflags	or  --mod-
	   version. The PKG_CONFIG_DEBUG_SPEW environment variable overrides this option.

       --uninstalled

	   Normally,  if  you request the package foo and the package foo-uninstalled exists, pkg-config will prefer the uninstalled variant. This
	   allows compilation/linking against uninstalled packages.  If you specify the --uninstalled option, pkg-config returns  successfully	if
	   any	uninstalled packages are being used. Otherwise, pkg-config fails. The PKG_CONFIG_DISABLE_UNINSTALLED environment variable prevents
	   pkg-config from implicitly choosing uninstalled packages.  If the PKG_CONFIG_DISABLE_UNINSTALLED variable is set, uninstalled  packages
	   are used only if you explicitly pass a name such as foo-uninstalled on the command line.

       --variable=variablename

	   Returns the value of a variable defined in a package's .pc file. For example, most packages define the variable prefix:

	   $ pkg-config --variable=prefix glib-2.0 /usr/

ENVIRONMENT VARIABLES

       See environ(5) for descriptions of environment variables.

       PKG_CONFIG_ALLOW_SYSTEM_CDoAnot strip -I/usr/include from cflags.

       PKG_CONFIG_ALLOW_SYSTEM_DoBnot strip -L/usr/lib from libs.

       PKG_CONFIG_DEBUG_SPEW   If set, causes pkg-config to print all debugging information and report all errors.

       PKG_CONFIG_DISABLE_UNINSTNormally,  if  you  request  the  package foo and the package foo-uninstalled exists, pkg-config prefers the unin-
			       stalled variant. This allows compilation/linking against  uninstalled  packages.  If  the  PKG_CONFIG_DISABLE_UNIN-
			       STALLED environment variable is set, pkg-config prefers the installed variant.

       PKG_CONFIG_PATH	       A colon-separated (on Windows, semicolon-separated) list of directories to search for .pc files. The default direc-
			       tory is always searched after searching the path specified by  PKG_CONFIG_PATH.	 The  default  value  of  PKG_CON-
			       FIG_PATH  is libdir/pkgconfig, where libdir is the lib directory where pkg-config is installed. On Solaris systems,
			       libdir is /usr/lib.

       PKG_CONFIG_TOP_BUILD_DIRSets the value of the magic variable pc_top_builddir, which may appear in .pc files. If this  environment  variable
			       is not set, the default value '$(top_builddir)' is used.  The PKG_CONFIG_TOP_BUILD_DIR variable should refer to the
			       top builddir of the  Makefile  where  the  compile/link	flags  reported  by  pkg-config  are  used.  The  PKG_CON-
			       FIG_TOP_BUILD_DIR variable is only used when compiling/linking against a package that has not yet been installed.

EXAMPLES

       Example 1: Example .pc File

       Here is an example .pc file:

       # This is a comment
       prefix=/usr # this defines a variable
       exec_prefix=${prefix} # defining another variable in terms of the first
       libdir=${exec_prefix}/lib
       includedir=${prefix}/include

       Name: GObject# human-readable name
       Description: Object/type system for GLib # human-readable description
       Version: 1.3.1
       Requires: glib-2.0 = 1.3.1
       Conflicts: foobar <= 4.5
       Libs: -L${libdir} -lgobject-1.3
       Cflags: -I${includedir}/glib-2.0 -I${libdir}/glib/include

       Example 2: Adding a Library to the Set of Packages Known to pkg-config

       To  add	a  library  to	the  set of packages known to pkg-config, you must install the library-specific .pc file in the /usr/lib/pkgconfig
       directory.

       If the .pc file does not exist, generate the file by running the configure command. Generating the file in this way ensures that the prefix
       and other variables are set to the correct values.

       Example 3: Getting the Compile Flags Required for the gnomeui Package

       example% pkg-config --cflags libgnomeui-2.0

FILES

       The following files are used by this application:

       /usr/bin/pkg-config     Executable for installed library helper script

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWgnome-common-devel	   |
       +-----------------------------+-----------------------------+
       |Interface stability	     |External			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       Latest version of the GNOME Desktop User Guide for your platform.

NOTES

       Updated	by  Brian Cameron, Sun Microsystems Inc., 2003, 2004. Written by James Henstridge, Martijn van Beers, Havoc Pennington, Tim Janik,
       Owen Taylor, Raja Harinath, Miguel de Icaza.

SunOS 5.10							    15 Jul 2004 						     pkg-config(1)