Contents The Psmisc package contains the fuser, killall, pidof and pstree programs. Description fuser fuser displays the PIDs of processes using the specified files or file systems. killall killall sends a signal to all processes running any of the specified commands. pidof Pidof finds the process id's (pids) of the named programs and prints those id's on standard output. pstree pstree shows running processes as a tree.