Lsof

The correct title of this article is lsof. The initial letter is capitalized due to technical restrictions.

lsof is a command line tool that is used to report a list of all open files and the processes that opened them.

Open files in the system include disk files, pipes, network sockets and devices opened by all processes. One use for this command is when a disk cannot be unmounted because (unspecified) files are in use. The listing of open files can be consulted (suitably filtered if necessary) to identify the process that is using the files.

% lsof /var
COMMAND     PID     USER   FD   TYPE DEVICE SIZE/OFF     NODE NAME
syslogd     350     root    5w  VREG  222,5        0 440818 /var/adm/messages
syslogd     350     root    6w  VREG  222,5   339098   6248 /var/log/syslog
cron        353     root  cwd   VDIR  222,5      512 254550 /var -- atjobs

See also

• netstat
• strace
• List of Linux Programmes

External links

• lsof manpage on www.netadmintools.com
• Vic Abell's homepage, author of lsof.