NAME pidof -- find the process ID of a running program. SYNOPSIS pidof [-s] [-c] [-n] [-x] [-o omitpid[,omitpid..]] [-o omitpid[,omitpid..]..] program [program..]
pidof is a part of
sysvinit, but it is too linux specific.
Updated by Igor Pashev about 7 years ago
pidof and killall5 (= killall on illumos/solaris) are build from the same source file from the sysvinit package 
It looks like we only need this file and a patch for illumos procfs.
Thanks to Caleb James DeLisle.