Provided by: pkg-config_0.29.2-1ubuntu1_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_SYSTEM_INCLUDE_PATH
              A  path  variable  containing system directories searched by the compiler.  This is
              normally /usr/include.

       CPATH
       C_INCLUDE_PATH
       CPLUS_INCLUDE_PATH
              Additional paths to append to PKG_CONFIG_SYSTEM_INCLUDE_PATH.  These correspond  to
              environment  variables  used  by  many  compilers to affect the header search path.
              These are ignored on Windows builds when --msvc-syntax is in use.

       INCLUDE
              Additional paths to append to PKG_CONFIG_SYSTEM_INCLUDE_PATH on Windows builds when
              --msvc-syntax  is in use. This corresponds to the environment variable used by MSVC
              to add directories to the include file search path.

       PKG_CONFIG_ALLOW_SYSTEM_CFLAGS
              Don't strip system paths out of Cflags. See PKG_CONFIG_SYSTEM_INCLUDE_PATH for  the
              definition of system paths.

       PKG_CONFIG_SYSTEM_LIBRARY_PATH
              A  path  variable  containing  system  directories searched by the linker.  This is
              normally /usr/lib:/lib but is dependent on the pkg-config  build  and  can  contain
              other directories such as /usr/lib64.

       PKG_CONFIG_ALLOW_SYSTEM_LIBS
              Don't  strip  system  paths out of Libs. See PKG_CONFIG_SYSTEM_LIBRARY_PATH for the
              definition of system paths.

       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.

              If the first call to PKG_PROG_PKG_CONFIG is conditional,  then  it  will  not  work
              correctly  in  all  cases. Since many of the other macros such as PKG_CHECK_MODULES
              require  PKG_PROG_PKG_CONFIG   to   know   which   pkg-config   program   to   run,
              PKG_PROG_PKG_CONFIG  may  be  run for the first time from a conditional from one of
              these macros. Therefore, if any of the pkg-config  macros  will  be  used  under  a
              conditional,  it's  best  to run PKG_PROG_PKG_CONFIG before any of the other macros
              are used.

       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_PROG_PKGCONFIG 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)