This is my fork of libxdg-basedir, by Mark Nevill. The original appears to be unmaintained.
I have fixed an obvious bug and performed minor cleanup up the code. More importantly, I intend to issue new releases when fixes are made. I cannot attest as to the quality but will accept pull requests containing bug fixes.
libxdg-basedir is "An implementation of the XDG Base Directory specifications". These specifications set a standard for where applications should find/store preferences, cache files, and other run-time files/data, mostly based on the values of certain environment variables.
I'm not a huge fan of the specifications: the arbitrary requirement that timestamps on files be updated periodically to avoid cleanup places an unnecessary burden on applications, and the workaround of setting the sticky bit is an abuse of a defunct feature. However, having a way of specifying where certain kinds of files should be placed is useful, and applications do make use of the specification (and this library).
There appears to be doxygen-based comments, but I have not attempted to build documentation.
The library uses autotools so can usually be built and installed via an invocation similar to:
./configure --prefix=/usr
make
make install
You can install to an alternate root location (for creation of packages etc) using
make DESTDIR=/some/directory install. Use ./configure --help for available configuration
options.