NAME

     file.pc — pkg-config file format

DESCRIPTION

     pkg-config files provide a useful mechanism for storing various information about libraries
     and packages on a given system.  Information stored by .pc files include compiler and linker
     flags necessary to use a given library, as well as any other relevant metadata.

     These .pc files are processed by a utility called pkg-config, of which pkgconf is an
     implementation.

   FILE SYNTAX
     The .pc file follows a format inspired by RFC822.  Comments are prefixed by a pound sign,
     hash sign or octothorpe (#), and variable assignment is similar to POSIX shell.  Properties
     are defined using RFC822-style stanzas.

   VARIABLES
     Variable definitions start with an alphanumeric string, followed by an equal sign, and then
     the value the variable should contain.

     Variable references are always written as "${variable}".  It is possible to escape literal
     "${" as "$${".

   PROPERTIES
     Properties are set using RFC822-style stanzas which consist of a keyword, followed by a
     colon (:) and then the value the property should be set to.  Variable substitution is always
     performed regardless of property type.

     There are three types of property:

     Literal
             The property will be set to the text of the value.

     Dependency List
             The property will be set to a list of dependencies parsed from the text.  Dependency
             lists are defined by this ABNF syntax:

             package-list = *WSP *( package-spec *( package-sep ) )
             package-sep  = WSP / ","
             package-spec = package-key [ ver-op package-version ]
             ver-op       = "<" / "<=" / "=" / "!=" / ">=" / ">"

     Fragment List
             The property will be set to a list of fragments parsed from the text.  The input
             text must be in a format that is suitable for passing to a POSIX shell without any
             shell expansions after variable substitution has been done.

   PROPERTY KEYWORDS
     Name    The displayed name of the package.  (mandatory; literal)

     Version
             The version of the package.  (mandatory; literal)

     Description
             A description of the package.  (mandatory; literal)

     URL     A URL to a webpage for the package.  This is used to recommend where newer versions
             of the package can be acquired.  (mandatory; literal)

     Cflags  Required compiler flags.  These flags are always used, regardless of whether static
             compilation is requested.  (optional; fragment list)

     Cflags.private
             Required compiler flags for static compilation.  (optional; fragment list; pkgconf
             extension)

     Libs    Required linking flags for this package.  Libraries this package depends on for
             linking against it, which are not described as dependencies should be specified
             here.  (optional; fragment list)

     Libs.private
             Required linking flags for this package that are only required when linking
             statically.  Libraries this package depends on for linking against it statically,
             which are not described as dependencies should be specified here.  (optional;
             fragment list)

     Requires
             Required dependencies that must be met for the package to be usable.  All
             dependencies must be satisfied or the pkg-config implementation must not use the
             package.  (optional; dependency list)

     Requires.private
             Required dependencies that must be met for the package to be usable for static
             linking.  All dependencies must be satisfied or the pkg-config implementation must
             not use the package for static linking.  (optional; dependency list)

     Conflicts
             Dependencies that must not be met for the package to be usable.  If any package in
             the proposed dependency solution match any dependency in the Conflicts list, the
             package being considered is not usable.  (optional; dependency list)

     Provides
             Dependencies that may be provided by an alternate package.  If a package cannot be
             found, the entire package collection is scanned for providers which can match the
             requested dependency.  (optional; dependency list; pkgconf extension)

   EXTENSIONS
     Features that have been marked as a pkgconf extension are only guaranteed to work with the
     pkgconf implementation of pkg-config.  Other implementations may or may not support the
     extensions.

     Accordingly, it is suggested that .pc files which absolutely depend on these extensions
     declare a requirement on the pkgconf virtual.

EXAMPLES

     An example .pc file:

     # This is a comment
     prefix=/home/kaniini/pkg   # this defines a variable
     exec_prefix=${prefix}      # defining another variable with a substitution
     libdir=${exec_prefix}/lib
     includedir=${prefix}/include

     Name: libfoo                                  # human-readable name
     Description: an example library called libfoo # human-readable description
     Version: 1.0
     URL: http://www.pkgconf.org
     Requires: libbar > 2.0.0
     Conflicts: libbaz <= 3.0.0
     Libs: -L${libdir} -lfoo
     Libs.private: -lm
     Cflags: -I${includedir}/libfoo

SEE ALSO

     pkgconf(1), pkg.m4(7)