Arch Linux

sometimes it’s useful to remove file extensions or other parts of a path, or extract e.g. the major version out of $pkgver.

that’s easily possible using bash parameter substitution, but breaks the package listing of the packages doing it, e.g.:
https://aur.archlinux.org/packages/glib2-ubuntu/
which does ${pkgver%.*} to remove the micro version (e.g. it yields "2.37" for a $pkgver set to "2.37.1")

doc:
http://tldp.org/LDP/abs/html/parameter-substitution.html