4.6 Dependencies

4.6.1 LIB_DEPENDS

This variable specifies the shared libraries this port depends on. It is a list of lib:dir[:target] tuples where lib is the name of the shared library, dir is the directory in which to find it in case it is not available, and target is the target to call in that directory. For example,

     LIB_DEPENDS=
                  jpeg.9:${PORTSDIR}/graphics/jpeg:install

will check for a shared jpeg library with major version 9, and descend into the graphics/jpeg subdirectory of your ports tree to build and install it if it is not found. The target part can be omitted if it is equal to DEPENDS_TARGET (which defaults to install).

The dependency is checked twice, once from within the extract target and then from within the install target. Also, the name of the dependency is put into the package so that pkg_add will automatically install it if it is not on the user's system.

4.6.2 RUN_DEPENDS

This variable specifies executables or files this port depends on during run-time. It is a list of path:dir[:target] tuples where path is the name of the executable or file, dir is the directory in which to find it in case it is not available, and target is the target to call in that directory. If path starts with a slash (/), it is treated as a file and its existence is tested with test -e; otherwise, it is assumed to be an executable, and which -s is used to determine if the program exists in the user's search path.

For example,

    RUN_DEPENDS=   ${LOCALBASE}/etc/innd:${PORTSDIR}/news/inn \
                   wish8.0:${PORTSDIR}/x11-toolkits/tk80

will check if the file or directory /usr/local/etc/innd exists, and build and install it from the news/inn subdirectory of the ports tree if it is not found. It will also see if an executable called wish8.0 is in your search path, and descend into the x11-toolkits/tk80 subdirectory of your ports tree to build and install it if it is not found.

The dependency is checked from within the install target. Also, the name of the dependency is put into the package so that pkg_add will automatically install it if it is not on the user's system. The target part can be omitted if it is the same as DEPENDS_TARGET.

4.6.3 BUILD_DEPENDS

This variable specifies executables or files this port requires to build. Like RUN_DEPENDS, it is a list of path:dir[:target] tuples. For example,

     BUILD_DEPENDS=
                  unzip:${PORTSDIR}/archivers/unzip

will check for an executable called unzip, and descend into the archivers/unzip subdirectory of your ports tree to build and install it if it is not found.

4.6.4 FETCH_DEPENDS

This variable specifies executables or files this port requires to fetch. Like the previous two, it is a list of path:dir[:target] tuples. For example,

     FETCH_DEPENDS=
                  ncftp2:${PORTSDIR}/net/ncftp2

will check for an executable called ncftp2, and descend into the net/ncftp2 subdirectory of your ports tree to build and install it if it is not found.

The dependency is checked from within the fetch target. The target part can be omitted if it is the same as DEPENDS_TARGET.

4.6.5 DEPENDS

If there is a dependency that does not fall into either of the above four categories, or your port requires having the source of the other port extracted in addition to having it installed, then use this variable. This is a list of dir[:target], as there is nothing to check, unlike the previous four. The target part can be omitted if it is the same as DEPENDS_TARGET.

4.6.6 USE_*

A number of variables exist in order to encapsulate common dependencies that many ports have.

Define USE_XLIB=yes if your port requires the X Window System to be installed (it is implied by USE_IMAKE). Define USE_GMAKE=yes if your port requires GNU make instead of BSD make. Define USE_AUTOCONF=yes if your port requires GNU autoconf to be run. Define USE_QT=yes if your port uses the latest qt toolkit. Use USE_PERL5=yes if your port requires version 5 of the perl language. (The last is especially important since some versions of FreeBSD have perl5 as part of the base system while others do not.)

4.6.7 Notes on dependencies

As mentioned above, the default target to call when a dependency is required is DEPENDS_TARGET. It defaults to install. This is a user variable; it is never defined in a port's Makefile. If your port needs a special way to handle a dependency, use the :target part of the *_DEPENDS variables instead of redefining DEPENDS_TARGET.

When you type make clean, its dependencies are automatically cleaned too. If you do not wish this to happen, define the variable NOCLEANDEPENDS in your environment.

To depend on another port unconditionally, use the variable ${NONEXISTENT} as the first field of BUILD_DEPENDS or RUN_DEPENDS. Use this only when you need to get the source of the other port. You can often save compilation time by specifying the target too. For instance

    BUILD_DEPENDS=   ${NONEXISTENT}:${PORTSDIR}/graphics/jpeg:extract

will always descend to the JPEG port and extract it.

Do not use DEPENDS unless there is no other way the behavior you want can be accomplished. It will cause the other port to always be built (and installed, by default), and the dependency will go into the packages as well. If this is really what you need, you should probably write it as BUILD_DEPENDS and RUN_DEPENDS instead--at least the intention will be clear.

4.6.8 Optional dependencies

Some large applications can be built in a number of configurations, adding functionality if one of a number of libraries or applications is available. Since not all users want those libraries or applications, the ports system provides hooks that the port author can use to decide which configuration should be built. Supporting these properly will make users happy, and effectively provide 2 or more ports for the price of one.

The easiest of these to use is WITHOUT_X11. If the port can be built both with and without X support, then it should normally be built with X support. If WITHOUT_X11 is defined, then the version that does not have X support should be built.

Various parts of GNOME have such knobs, though they are slightly more difficult to use. The variables to use in the Makefile are WANT_* and HAVE_*. If the application can be built both with or without one of the dependencies listed below, then the Makefile should set WANT_PKG, and should build the version that uses PKG if HAVE_PKG is defined.

The WANT_* variables currently supported this way are WANT_GLIB, WANT_GTK, WANT_ESOUND, WANT_IMLIB, and WANT_GNOME.