lockf(8)
NAME
lockf - lock files from within shell-scripts (used by sn news system)
SYNOPSIS
lockf
DESCRIPTION
lockf can be used to lock files from within shell-scripts. Filedescriptor 3 is always locked, and the lock remains until the process is
killed. The process-id is written to standard output, as to facilitate
killing the process.
It is used by the sn news system.