PKG-CONFIG

Using pkg-config to set variables

When compiling software from source you might need to set variables such as $CFLAGS or $LDFLAGS. Here the pkg-config command comes handy. You can easily set this variables by typing (tcsh):

> setenv CFLAGS `"pkg-config --cflags PACKAGE-NAME"`

and

> setenv LDLAGS `"pkg-config --libs PACKAGE-NAME"`

where PACKAGE-NAME is the package you need. However, pkg-config looks for packages contained in the $PATH variable only. If you need pkg-config to search in a non default path you may set the $PKG_CONFIG_PATH variable accordingly. This variable must contain paths leading to a directory containing *.pc files. Very often a package comes with a pkg-config directory containing the corresponding *.pc files. You may set multiple paths in the $PKG_CONFIG_PATH variable using : as separator.

It is important to note that the --libs option sometimes only returns the link time directory, omitting the run time directory. Therefore, you might have to correct the LDFLAGS variable accordingly.

Remark: Paths contained in $PKG_CONFIG_PATH are preferred over the default paths by pkg-config.

Here is an example (again in tcsh):

> setenv CFLAGS `"pkg-config --cflags gtk+-2.0"`

type man pkg-config fore further information.