PKG-CONFIG(1)

NAME
pkg-config - a system for configuring build dependency information

SYNOPSIS
pkg-config [options] module ...

DESCRIPTION
pkg-config is a program which helps to configure compiler and linker flags for development libraries. This allows build systems to detect other dependencies and use them with the system toolchain.

The options are as follows:

--about
    Print the version number, the Copyright notice, and the license of the pkg-config program to standard output and exit. Most other options and all command line arguments are ignored.

--atleast-pkgconfig-version=version
    Exit with error if the requested version number is greater than the version number of the pkg-config program.

--atleast-version=version
    Exit with error if the version number of each module is less than the specified version number.

--cflags, --cflags-only-I, --cflags-only-other
    Print all compiler flags required to compile against the module, or only the include path (-I) flags, or only the compiler flags that are not include path flags, respectively. These options imply --print-errors.

--debug
    Print some non-fatal warning messages to standard error output that would otherwise silently be ignored. This option also implies --print-errors. If pkg-config was compiled without defining the preprocessor macro PKGCONF_LITE, this option also prints many debugging messages to standard error output.

--define-prefix
    Attempts to determine the prefix variable to use for CFLAGS and LIBS entry relocations. This is mainly useful for platforms where framework SDKs are relocatable, such as Windows.

--define-variable=varname=value
    Define varname as value. Variables are used in query output, and some modules' results may change based on the presence of a variable definition.

--digraph
    Dump the dependency resolver's solution as a graphviz ‘dot’ file. This can be used with graphviz to visualize module interdependencies. This option is only available if the preprocessor macro PKGCONF_LITE was not defined during compilation.

--dont-define-prefix
    Disables the ‘define-prefix’ feature.

--dont-relocate-paths
    Disables the path relocation feature.

--env=varname
    Print the requested values as variable declarations in a similar format as the env(1) command.

--env-only
    Initialize the module search path from --with-path and PKG_CONFIG_PATH only, ignoring PKG_CONFIG_LIBDIR and the compiled-in default directories.

--errors-to-stdout
    Print all error, warning, and debugging messages to standard output instead of to standard error output.

--exact-version=version
    Exit with error if no module has exactly the specified version number.

--exists
    Exit with a non-zero exit status if the dependency resolver is unable to find all of the requested modules. This option is active by default and cannot be disabled. However, various other options cause pkg-config to exit and report success or failure before all arguments have been inspected.

--fragment-filter=types
    Filter the fragment lists for the specified types.

--ignore-conflicts
    Ignore ‘Conflicts’ rules in modules.

--keep-system-cflags, --keep-system-libs
    Keep CFLAGS or linker flag fragments that would be filtered due to being included by default in the compiler.

--libs, --libs-only-L, --libs-only-l, --libs-only-other
    Print all linker flags required to link against the module, or only the library path (-L) flags, or only the library (-l) flags, or only the linker flags that are neither library path nor library flags, respectively. These options imply --print-errors.

--list-all
    Walk the module search path in the order of descending priority. For each pc(5) file found, print one line to standard output, containing the basename of the file without the extension, the Name property, a dash (‘-’), and the Description property. This option implies --print-errors.

--list-package-names
    Perform the same search as --list-all, but only print the basename of each pc(5) file without the extension, not the module name and the description. This option implies --print-errors.

--log-file=file
    Set the name of the output file where information about selected modules is logged, both about those selected by arguments and as dependencies. For each selected module, one line is printed to standard output, containing the basename of the pc(5) file without the extension, optionally an operator and version number describing the desired range of versions, and either the actual version number in square brackets or the string "NOT-FOUND". If this option is not provided, the name of the output file is instead taken from the PKG_CONFIG_LOG environment variable, and if that is not provided either, this kind of logging is disabled.

--max-version=version
    Exit with error if the version number of each module is greater than the specified version number.

--maximum-traverse-depth=depth
    Impose a limit on the allowed depth in the dependency graph. For example, a depth of 2 restricts the resolver from acting on child dependencies of modules added to the resolver's solution. This option is overridden by the PKG_CONFIG_MAXIMUM_TRAVERSE_DEPTH environment variable and by the options --modversion, --path, --print-provides, --print-requires, --print-requires-private, --print-variables, and --variable.

--modversion
    For each specified module, print the version number to standard output. If the --verbose option is also specified, the name of the respective module and a colon is printed before each version number. This option implies --print-errors and --maximum-traverse-depth=1 and overrides and disables all --cflags and --libs flags.

--msvc-syntax
    Use MSVC syntax for --cflags, --env, and --libs output. This option is only available if the preprocessor macro PKGCONF_LITE was not defined during compilation.

--no-cache
    Skip caching packages when they are loaded into the internal resolver. This may result in an alternate dependency graph being computed.

--no-provides
    Ignore ‘Provides’ rules in modules when resolving dependencies.

--no-uninstalled
    Forbids the dependency resolver from considering 'uninstalled' modules as part of a solution.

--path
    For the first module given on the command line, let the dependency resolver find the pc(5) file describing that module, print the absolute pathname of that file to standard output, and exit immediately, ignoring most other options and all other arguments.

--prefix-variable=variable
    Sets the ‘prefix’ variable used by the ‘define-prefix’ feature.

--print-errors
    Print some messages about fatal errors to standard error output that would otherwise be omitted. This option is implied by many other options, but not by all. It can be overridden with --silence-errors.

--print-provides
    For each specified module, print one line to standard output containing the Name property, an equal sign (‘=’), and the Version property. If the module contains one or more Provides properties, print additional lines in dependency list format, one name per line, each name optionally followed by an operator and a version. This option implies --maximum-traverse-depth=1 and overrides and disables all --cflags and --libs flags.

--print-requires, --print-requires-private
    For each specified module, print the Requires or Requires.private properties, respectively, in dependency list format to standard output. Both of these options imply --maximum-traverse-depth=1 and override and disable all --cflags and --libs flags.

--print-variables
    For the first module given on the command line, print the names of all seen variables to standard output, one per line. Any subsequent arguments are silently ignored. This option implies --print-errors and --maximum-traverse-depth=1 and overrides and disables all --cflags and --libs flags.

--pure
    Treats the computed dependency graph as if it were pure. This is mainly intended for use with the --static flag and has no effect if --shared is also specified.

--relocate=path
    Relocates a path using the pkgconf_path_relocate API. This is mainly used by the testsuite to provide a guaranteed interface to the system's path relocation backend.

--shared
    Compute a simple dependency graph that is only suitable for shared linking. This option overrides --static.

--short-errors
    When printing error messages about modules that are not found or conflict with each other, avoid printing additional, verbose instructions explaining potential methods for solving the problem.

--silence-errors
    Do not print any error, warning, or debugging messages at all. Overrides all of --debug, --errors-to-stdout, and --print-errors. This option is overridden and disabled if the PKG_CONFIG_DEBUG_SPEW environment variable is set.

--simulate
    Simulates resolving a dependency graph based on the requested modules on the command line. Dumps a series of trees denoting pkgconf's resolver state. This option is only available if the preprocessor macro PKGCONF_LITE was not defined during compilation.

--static
    Compute a deeper dependency graph and use compiler/linker flags intended for static linking. This option is overridden by --shared.

--uninstalled
    Exit with a non-zero result if the dependency resolver uses an ‘uninstalled’ module as part of its solution.

--validate package ...
    Validate specific ‘.pc’ files for correctness. This option implies --print-errors and --errors-to-stdout.

--variable=varname
    For the first module given on the command line, print the value of the variable with the name varname to standard output. Any subsequent arguments are silently ignored. This option implies --maximum-traverse-depth=1 and overrides and disables all --cflags and --libs flags.

--verbose
    This option only has an effect if --modversion is also specified. It prints the name of the respective module and a colon before each version number.

--version
    Print the version number of the pkg-config program to standard output and exit. Most other options and all command line arguments are ignored.

--with-path=path
    Prepend the directory path to the module search path, giving it priority over all other directories including those from PKG_CONFIG_PATH and PKG_CONFIG_LIBDIR.

ENVIRONMENT

CPATH
    First supplementary colon-separated list of include paths filtered out in the same way as PKG_CONFIG_SYSTEM_INCLUDE_PATH.

CPLUS_INCLUDE_PATH
    Third supplementary colon-separated list of include paths filtered out in the same way as PKG_CONFIG_SYSTEM_INCLUDE_PATH.

C_INCLUDE_PATH
    Second supplementary colon-separated list of include paths filtered out in the same way as PKG_CONFIG_SYSTEM_INCLUDE_PATH.

DESTDIR
    If set to PKG_CONFIG_SYSROOT_DIR, assume that PKG_CONFIG_FDO_SYSROOT_RULES is set.

LIBRARY_PATH
    Supplementary colon-separated list of library paths filtered out in the same way as PKG_CONFIG_SYSTEM_LIBRARY_PATH.

OBJC_INCLUDE_PATH
    Fourth supplementary colon-separated list of include paths filtered out in the same way as PKG_CONFIG_SYSTEM_INCLUDE_PATH.

PKG_CONFIG_DEBUG_SPEW
    If set, override and disable the --silence-errors option.

PKG_CONFIG_DISABLE_UNINSTALLED
    If set, enables the same behaviour as the --no-uninstalled flag.

PKG_CONFIG_DONT_DEFINE_PREFIX
    If set, this variable has the same effect as the --dont-define-prefix option.

PKG_CONFIG_DONT_RELOCATE_PATHS
    If set, disables the path relocation feature.

PKG_CONFIG_FDO_SYSROOT_RULES
    If set, follow the sysroot prefixing rules that freedesktop.org pkg-config uses.

PKG_CONFIG_IGNORE_CONFLICTS
    If set, ignore Conflicts rules in modules. Has the same effect as the --ignore-conflicts option.

PKG_CONFIG_LIBDIR
    A colon-separated list of low-priority directories where pc(5) files are looked up. The module search path is constructed by appending this list to PKG_CONFIG_PATH, which enjoys higher priority. If PKG_CONFIG_LIBDIR is not defined, the default list compiled into the pkg-config program from the PKG_DEFAULT_PATH preprocessor macro is appended instead. If PKG_CONFIG_LIBDIR is defined but empty, nothing is appended.

PKG_CONFIG_LOG
    If set, log information about selected modules to the file with the name stored in this variable. For more details, see the --log-file command line option, which overrides this variable.

PKG_CONFIG_MAXIMUM_TRAVERSE_DEPTH
    Impose a limit on the allowed depth in the dependency graph. This variable overrides the --maximum-traverse-depth option, but is overriden by the other options mentioned there.

PKG_CONFIG_MSVC_SYNTAX
    If set, use MSVC syntax for --cflags, --env, and --libs output. This variable has the same effect as the --msvc-syntax option. If the preprocessor macro PKGCONF_LITE was defined during compilation, this variable is ignored.

PKG_CONFIG_PATH
    A colon-separated list of high-priority directories where pc(5) files are looked up. The module search path is constructed by prepending the directory specified with --with-path, if any, and unless --env-only is specified, by appending either PKG_CONFIG_LIBDIR or the compiled-in default directories with lower priority.

PKG_CONFIG_PURE_DEPGRAPH
    If set, enables the same behaviour as the --pure flag.

PKG_CONFIG_RELOCATE_PATHS
    If set, this variable has the same effect as the --define-prefix option.

PKG_CONFIG_SYSROOT_DIR
    ‘sysroot’ directory, will be prepended to every path defined in PKG_CONFIG_PATH. Useful for cross compilation.

PKG_CONFIG_SYSTEM_INCLUDE_PATH
    Colon-separated list of include paths that are filtered out and not printed by the --cflags and --cflags-only-I options because they are considered system include paths. If not defined, the default list compiled into the pkg-config program from the SYSTEM_INCLUDEDIR preprocessor macro is used instead. This variable is a pkgconf-specific extension. Any directories listed in the environment variables CPATH, C_INCLUDE_PATH, CPLUS_INCLUDE_PATH, and OBJC_INCLUDE_PATH are also filtered out.

PKG_CONFIG_SYSTEM_LIBRARY_PATH
    Colon-separated list of library paths that are filtered out and not printed by the --libs and --libs-only-L options because they are considered system library paths. If not defined, the default list compiled into the pkg-config program from the SYSTEM_LIBDIR preprocessor macro is used instead. This variable is a pkgconf-specific extension.

PKG_CONFIG_TOP_BUILD_DIR
    The value of the pc_top_builddir global variable. If this environment variable is not defined, the string "$(top_builddir)" is used as the value of pc_top_builddir.

EXIT STATUS

EXAMPLES
Displaying the CFLAGS of a package:
    $ pkg-config --cflags foo
    -fPIC -I/usr/include/foo

SEE ALSO
pc(5), pkg.m4(7)