Binary package “libfile-which-perl” in ubuntu bionic

Perl module for searching paths for executable programs

 File::Which simulates the behavior of the standard 'which' program: it
 searches directories of a user's PATH (as returned by File::Spec)
 looking for executable files matching a given name.
 .
 On Debian /usr/bin/which is guaranteed to be available, but going
 through the Perl implementation can still save a fork.