Provided by: pkg-config_0.29.1-0ubuntu3_amd64 bug

NAME

       pkg-config - Return metainformation about installed libraries

SYNOPSIS

       pkg-config   [--modversion]   [--version]  [--help]  [--atleast-pkgconfig-version=VERSION]
       [--print-errors]  [--short-errors]   [--silence-errors]   [--errors-to-stdout]   [--debug]
       [--cflags]  [--libs] [--libs-only-L] [--libs-only-l] [--cflags-only-I] [--libs-only-other]
       [--cflags-only-other]                 [--variable=VARIABLENAME]                 [--define-
       variable=VARIABLENAME=VARIABLEVALUE]    [--print-variables]   [--uninstalled]   [--exists]
       [--atleast-version=VERSION] [--exact-version=VERSION] [--max-version=VERSION] [--validate]
       [--list-all]      [--print-provides]     [--print-requires]     [--print-requires-private]
       [LIBRARIES...]

DESCRIPTION

       The pkg-config program is used to retrieve information about installed  libraries  in  the
       system.   It is typically used to compile and link against one or more libraries.  Here is
       a typical usage scenario 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
       are  named  after the package, and has a .pc extension.  On most systems, pkg-config looks
       in     /usr/lib/pkgconfig,     /usr/share/pkgconfig,     /usr/local/lib/pkgconfig      and
       /usr/local/share/pkgconfig  for  these  files.   It  will  additionally look in the colon-
       separated  (on  Windows,  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, minus 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 "gtk+-2.0").

       In addition to specifying a package name on the command line, the full path to a given .pc
       file may be given instead. This allows a user to directly query a particular .pc file.

OPTIONS

       The following options are supported:

       --modversion
              Requests  that  the  version  information of the libraries specified on the command
              line be displayed.  If pkg-config can find all 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.

       --version
              Displays the version of pkg-config and terminates.

       --atleast-pkgconfig-version=VERSION
              Requires at least the given version of pkg-config.

       --help Displays a help message and terminates.

       --print-errors
              If  one  or more of the modules on the command line, or their dependencies, are not
              found, or if an error occurs in parsing a .pc file, then  this  option  will  cause
              errors  explaining  the  problem  to  be  printed. With "predicate" options such as
              "--exists" pkg-config runs silently  by  default,  because  it's  usually  used  in
              scripts  that want to control what's output. 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.

       --short-errors
              Print short error messages.

       --silence-errors
              If  one  or more of the modules on the command line, or their dependencies, are not
              found, or if an error occurs in parsing a a .pc file, then this  option  will  keep
              errors  explaining the problem from being printed. With "predicate" options such as
              "--exists" pkg-config runs silently  by  default,  because  it's  usually  used  in
              scripts  that  want  to  control  what's output. So this option is only useful with
              options such as "--cflags" or "--modversion" that  print  errors  by  default.  The
              PKG_CONFIG_DEBUG_SPEW environment variable overrides this option.

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

       --debug
              Print    debugging    information.    This   is   slightly   different   than   the
              PKG_CONFIG_DEBUG_SPEW environment variable, which also enable "--print-errors".

       The following options are used to compile and link programs:

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

       --cflags-only-I
              This  prints  the -I part of "--cflags". That is, it defines the header search path
              but doesn't specify anything else.

       --cflags-only-other
              This prints parts of "--cflags" not covered by "--cflags-only-I".

       --libs This option is identical to "--cflags", only it prints  the  link  flags.  As  with
              "--cflags", duplicate flags are merged (maintaining proper ordering), and flags for
              dependencies are included in the output.

       --libs-only-L
              This prints the -L/-R part of "--libs". That is, it defines the library search path
              but doesn't specify which libraries to link with.

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

       --libs-only-other
              This  prints the parts of "--libs" not covered by "--libs-only-L" and "--libs-only-
              l", such as "--pthread".

       --variable=VARIABLENAME
              This returns the value of a variable defined in a package's .pc file. Most packages
              define the variable "prefix", for example, so you can say:
                $ pkg-config --variable=prefix glib-2.0
                /usr/

       --define-variable=VARIABLENAME=VARIABLEVALUE
              This  sets  a  global  value for a variable, overriding the value in any .pc files.
              Most packages define the variable "prefix", for example, so you can say:
                $ pkg-config --print-errors --define-variable=prefix=/foo \
                             --variable=prefix glib-2.0
                /foo

       --print-variables
              Returns a list of all variables defined in the package.

       --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
              will  return successfully if any "-uninstalled" packages are being used, and return
              failure  (false)  otherwise.    (The   PKG_CONFIG_DISABLE_UNINSTALLED   environment
              variable  keeps  pkg-config from implicitly choosing "-uninstalled" packages, so if
              that variable is set, they will only have been used if you pass a name  like  "foo-
              uninstalled" on the command line explicitly.)

       --exists

       --atleast-version=VERSION

       --exact-version=VERSION

       --max-version=VERSION
              These  options test whether the package or list of packages on the command line are
              known to pkg-config, and optionally whether the version number of a  package  meets
              certain  constraints.   If  all  packages  exist  and  meet  the  specified version
              constraints, pkg-config exits successfully. Otherwise it exits unsuccessfully. Only
              the first VERSION comparing option will be honored. Subsequent options of this type
              will be ignored.

              Rather than  using  the  version-test  options,  you  can  simply  give  a  version
              constraint after each package name, for example:
                $ pkg-config --exists 'glib-2.0 >= 1.3.4 libxml = 1.8.3'
              Remember  to  use --print-errors if you want error messages. When no output options
              are supplied to pkg-config, --exists is implied.

       --validate
              Checks the syntax of a package's .pc  file  for  validity.  This  is  the  same  as
              --exists  except that dependencies are not verified. This can be useful for package
              developers to test their .pc file prior to release:
                $ pkg-config --validate ./my-package.pc

       --msvc-syntax
              This option is available only on Windows. It causes pkg-config to output -l and  -L
              flags in the form recognized by the Microsoft Visual C++ command-line compiler, cl.
              Specifically, instead of -Lx:/some/path it prints /libpath:x/some/path, and instead
              of  -lfoo  it prints foo.lib. Note that the --libs output consists of flags for the
              linker, and should be placed on the cl command line after a /link switch.

       --define-prefix
       --dont-define-prefix
              These options control whether pkg-config overrides the value of the variable prefix
              in  each  .pc file. With --define-prefix, pkg-config uses the installed location of
              the .pc file to determine the prefix. --dont-define-prefix prevents this  behavior.
              The default is usually --define-prefix.

              When  this  feature  is  enabled  and  a  .pc  file  is  found in a directory named
              pkgconfig, the prefix for that package is assumed to  be  the  grandparent  of  the
              directory  where the file was found, and the prefix variable is overridden for that
              file accordingly.

              If the value of a variable in a .pc file begins with the original,  non-overridden,
              value  of the prefix variable, then the overridden value of prefix is used instead.
              This allows the feature to work even when the variables have been expanded  in  the
              .pc file.

       --prefix-variable=PREFIX
              Set the name of the variable that pkg-config overrides instead of prefix when using
              the --define-prefix feature.

       --static
              Output libraries suitable for static linking.  That  means  including  any  private
              libraries  in  the  output.  This relies on proper tagging in the .pc files, else a
              too large number of libraries will ordinarily be output.

       --list-all
              List all modules found in the pkg-config path.

       --print-provides
              List all modules the given packages provides.

       --print-requires
              List all modules the given packages requires.

       --print-requires-private
              List all modules the given packages requires for static linking (see --static).

ENVIRONMENT VARIABLES

       PKG_CONFIG_PATH
              A colon-separated (on Windows, semicolon-separated) list of directories  to  search
              for  .pc  files.  The default directory will always be searched after searching the
              path; the default is libdir/pkgconfig:datadir/pkgconfig where libdir is the  libdir
              for pkg-config and datadir is the datadir for pkg-config when it was installed.

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

       PKG_CONFIG_TOP_BUILD_DIR
              A value to set for the magic variable  pc_top_builddir  which  may  appear  in  .pc
              files.  If the environment variable is not set, the default value '$(top_builddir)'
              will be used. This variable should refer to the top builddir of the Makefile  where
              the compile/link flags reported by pkg-config will be used.  This only matters when
              compiling/linking against a package that hasn't yet been installed.

       PKG_CONFIG_DISABLE_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 this environment variable  is  set,  it  disables
              said behavior.

       PKG_CONFIG_ALLOW_SYSTEM_CFLAGS
              Don't strip -I/usr/include out of cflags.

       PKG_CONFIG_ALLOW_SYSTEM_LIBS
              Don't strip -L/usr/lib or -L/lib out of libs.

       PKG_CONFIG_SYSROOT_DIR
              Modify  -I and -L to use the directories located in target sysroot.  this option is
              useful when cross-compiling packages that use pkg-config to  determine  CFLAGS  and
              LDFLAGS.  -I and -L are modified to point to the new system root. this means that a
              -I/usr/include/libfoo   will   become   -I/var/target/usr/include/libfoo   with   a
              PKG_CONFIG_SYSROOT_DIR equal to /var/target (same rule apply to -L)

       PKG_CONFIG_LIBDIR
              Replaces      the      default     pkg-config     search     directory,     usually
              /usr/lib/pkgconfig:/usr/share/pkgconfig.

       PKG_CONFIG_$PACKAGE_$VARIABLE
              Overrides the variable VARIABLE in the package PACKAGE.  The  environment  variable
              should have the package name and package variable upper cased with non-alphanumeric
              characters     converted     to     underscores.     For      example,      setting
              PKG_CONFIG_GLADEUI_2_0_CATALOGDIR  will  override  the variable "catalogdir" in the
              "gladeui-2.0" package.

PKG-CONFIG DERIVED VARIABLES

       pkg-config sets a few metadata variables that can be used  in  .pc  files  or  queried  at
       runtime.

       pc_path
              The  default  search path used by pkg-config when searching for .pc files. This can
              be used in a query for the pkg-config module itself itself:
                $ pkg-config --variable pc_path pkg-config

       pcfiledir
              The installed location of the .pc file. This can be used to query the  location  of
              the  .pc  file  for  a particular module, but it can also be used to make .pc files
              relocatable. For instance:
              prefix=${pcfiledir}/../..
              exec_prefix=${prefix}
              libdir=${exec_prefix}/lib
              includedir=${prefix}/include

       pc_sysrootdir
              The sysroot directory set by the user. When the sysroot directory has not been set,
              this  value  is  /.   See  the PKG_CONFIG_SYSROOT_DIR environment variable for more
              details.

       pc_top_builddir
              Location of the user's top build directory when calling pkg-config.  This is useful
              to dynamically set paths in uninstalled .pc files. See the PKG_CONFIG_TOP_BUILD_DIR
              environment variable for more details.

WINDOWS SPECIALITIES

       The pkg-config default search path is ignored on Windows.  Instead,  the  search  path  is
       constructed   by   using   the  installed  directory  of  pkg-config  and  then  appending
       lib\pkgconfig and share\pkgconfig.  This can be augmented or replaced using  the  standard
       environment variables described above.

AUTOCONF MACROS

       PKG_CHECK_MODULES(VARIABLE-PREFIX, MODULES [,ACTION-IF-FOUND [,ACTION-IF-NOT-FOUND]])

              The  macro  PKG_CHECK_MODULES  can be used in configure.ac to check whether modules
              exist. A typical usage would be:
               PKG_CHECK_MODULES([MYSTUFF], [gtk+-2.0 >= 1.3.5 libxml = 1.8.4])

              This would result in MYSTUFF_LIBS and MYSTUFF_CFLAGS substitution variables, set to
              the  libs  and cflags 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,  specify  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 display what went wrong.

              Note  that  if there is a possibility the first call to PKG_CHECK_MODULES might not
              happen, you should be sure to include an explicit call  to  PKG_PROG_PKG_CONFIG  in
              your configure.ac.

              Also  note  that  repeated  usage of VARIABLE-PREFIX is not recommended.  After the
              first successful usage, subsequent calls with the same VARIABLE-PREFIX will  simply
              use  the  _LIBS  and  _CFLAGS variables set from the previous usage without calling
              pkg-config again.

       PKG_PREREQ(MIN-VERSION)
              Checks that the version of the pkg-config autoconf macros in use is at  least  MIN-
              VERSION.  This  can  be  used  to  ensure  a  particular  pkg-config  macro will be
              available.

       PKG_PROG_PKG_CONFIG([MIN-VERSION])

              Defines the PKG_CONFIG variable to the best pkg-config  available,  useful  if  you
              need pkg-config but don't want to use PKG_CHECK_MODULES.

       PKG_CHECK_MODULES_STATIC(VARIABLE-PREFIX,   MODULES   [,ACTION-IF-FOUND   [,ACTION-IF-NOT-
       FOUND]])
              Enables static linking through --static prior to calling PKG_CHECK_MODULES.

       PKG_CHECK_EXISTS(MODULES, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])

              Check  to  see  whether  a  particular  set  of   modules   exists.    Similar   to
              PKG_CHECK_MODULES(), but does not set variables or print errors.

              Similar  to  PKG_CHECK_MODULES,  make  sure  that  the  first  instance  of this or
              PKG_CHECK_MODULES is called, or make sure to call PKG_CHECK_EXISTS manually.

       PKG_INSTALLDIR(DIRECTORY)

              Substitutes the variable pkgconfigdir as the location where a module should install
              pkg-config  .pc  files.  By  default  the  directory  is $libdir/pkgconfig, but the
              default can be changed by passing DIRECTORY.  The user  can  override  through  the
              --with-pkgconfigdir parameter.

       PKG_NOARCH_INSTALLDIR(DIRECTORY)

              Substitutes  the variable noarch_pkgconfigdir as the location where a module should
              install  arch-independent  pkg-config  .pc  files.  By  default  the  directory  is
              $datadir/pkgconfig,  but  the default can be changed by passing DIRECTORY. The user
              can override through the --with-noarch-pkgconfigdir parameter.

       PKG_CHECK_VAR(VARIABLE, MODULE, CONFIG-VARIABLE, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])

              Retrieves the value of the pkg-config  variable  CONFIG-VARIABLE  from  MODULE  and
              stores  it  in VARIABLE. Note that repeated usage of VARIABLE is not recommended as
              the check will be skipped if the variable is already set.

METADATA FILE SYNTAX

       To add a library to the set of packages pkg-config knows about, simply install a .pc file.
       You should install this file to libdir/pkgconfig.

       Here is an example file:
       # This is a comment
       prefix=/home/hp/unst   # 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
       URL: http://www.gtk.org
       Requires: glib-2.0 = 1.3.1
       Conflicts: foobar <= 4.5
       Libs: -L${libdir} -lgobject-1.3
       Libs.private: -lm
       Cflags: -I${includedir}/glib-2.0 -I${libdir}/glib/include

       You  would normally generate the file using configure, so that the prefix, etc. are set to
       the proper values.  The GNU Autoconf manual recommends generating files like .pc files  at
       build time rather than configure time, so when you build the .pc file is a matter of taste
       and preference.

       Files have two kinds of line: keyword lines  start  with  a  keyword  plus  a  colon,  and
       variable  definitions  start with an alphanumeric string plus an equals sign. Keywords are
       defined in advance and have special meaning to pkg-config; variables do not, you can  have
       any  variables  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 "$${".

       Name:  This field should be a human-readable name for the package. Note that it is not the
              name passed as an argument to pkg-config.

       Description:
              This should be a brief description of the package

       URL:   An URL where people can get more information about and download the package

       Version:
              This should be the most-specific-possible package version string.

       Requires:
              This is 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 one time on the Requires:
              line. If the version of a package is unspecified, any version will be used with  no
              checking.

       Requires.private:
              A  list  of packages required by this package. The difference from Requires is that
              the packages listed under Requires.private are not taken into account when  a  flag
              list  is  computed  for  dynamically linked executable (i.e., when --static was not
              specified).  In the situation  where  each  .pc  file  corresponds  to  a  library,
              Requires.private  shall be used exclusively to specify the dependencies between the
              libraries.

       Conflicts:
              This optional line 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  here,  for  example  "foobar  =
              1.2.3,  foobar  =  1.2.5, foobar >= 1.3", if you have reason to do so. If a version
              isn't specified, then 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, then pkg-config will complain.

       Libs:  This line should give the link flags specific to your package.  Don't add any flags
              for required packages; pkg-config will add those automatically.

       Libs.private:
              This  line  should  list  any  private  libraries  in  use.   Private libraries are
              libraries which are not exposed through your library, but are needed in the case of
              static  linking. This differs from Requires.private in that it references libraries
              that do not have package files installed.

       Cflags:
              This line should list the compile flags specific to your package.   Don't  add  any
              flags for required packages; pkg-config will add those automatically.

AUTHOR

       pkg-config  was written by James Henstridge, rewritten by Martijn van Beers, and rewritten
       again by Havoc Pennington. Tim Janik, Owen Taylor, and Raja Harinath submitted suggestions
       and  some  code.   gnome-config  was written by Miguel de Icaza, Raja Harinath and various
       hackers in the GNOME team.  It was inspired by Owen Taylor's gtk-config program.

BUGS

       pkg-config does not handle mixing of parameters with and without = well.  Stick with one.

       Bugs can be reported at http://bugs.freedesktop.org/ under the pkg-config component.

                                                                                    pkg-config(1)