Detect called filename to automatically unxz

[mbirth]

I've symlinked /usr/bin/pxz to /usr/local/bin/xz for me to use it whenever some tool tries to use the "normal" xz. However, there's also unxz which automatically uncompresses given files.

But when creating a symlink unxz, pxz is still in "compress" mode (and does nothing as it detects that the file is already compressed).

Could you add a feature to detect the called name and act accordingly (should work with unxz and probably punxz, too)?