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STMPCLEAN(8)           DragonFly System Manager's Manual          STMPCLEAN(8)

NAME
     stmpclean - remove old files from a world-writable directory

SYNOPSIS
     stmpclean [-t<timespec>] [-v] dir1 [dir2 ...]

DESCRIPTION
     The stmpclean utility removes old files (and old empty directories) from
     the specified directory.  It'll be typically used to clean directories
     such as ``/tmp'' where old files tend to accumulate.

     The stmpclean utility never removes files or directories owned by root.
     It is a feature, not a bug.  Great care is taken while descending into
     the directory, and the operation is secure.  Anything that's not a
     directory, regular file, or symbolic link is also left alone (because
     programs like screen(1) create sockets and FIFOs under /tmp and expect
     them to be long-lived; we accomodate this practice).  Unlike floating
     around Perl scripts that do the same task stmpclean never forks and
     consumes limited amount of memory (these Perl scripts easily turn into
     forking bombs when someone creates a lot a directories under ``/tmp'').
     If your system is attacked and the attacker creates an extremely deep
     file hierarchy, stmpclean won't add to the problem by crashing your
     system trying to remove it.  But it won't help you in fighting the
     attack, either, because it descends only to a limited depth (currently,
     30 levels).  If stmpclean determines a race condition it'll log the
     situation (you can look for the word ``RACE'' in log files) and exit with
     a failure.

     So, stmpclean will clean temporary directories for you fine when there
     are no attacks, and, when there is an attack, stmpclean won't make the
     situation worse (in particular, it cannot be tricked into removing files
     outside specified directories or consume unlimited amount of resources).

     The following option is available:

     -t<timespec>
           The time specification that follows the -t flag specifies how old a
           file or a directory has to be before it will be removed.  It can be
           a string like `1w' (one week) or `4d5h' (four days plus five hours)
           or `2m3s' (two minutes plus three seconds).  The default is `3d'
           (three days).

     -v    Be verbose: list each file deleted.

     The stmpclean utility exits 0 on success, and >0 if an error occurs.

EXAMPLES
     The stmpclean utility will typically be run nightly from cron(8) as

     stmpclean /tmp /var/tmp

     In FreeBSD stmpclean invokation should be placed into the file
     /etc/periodic/daily/110.clean-tmps.  In other versions of BSD it should
     go into the /etc/daily script.  In Linux, check if you have
     /etc/periodic, and if not, you can just run it from cron; usually you'd
     have to edit /etc/crontab.

SEE ALSO
     cron(8)

BUGS
     When stmpclean removes a file from a directory, modification time of the
     directory changes and it looks new to stmpclean when it examines it later
     (if the directory became empty).  Thus, removing a deep hierarchy can
     take some time.  Notice that this only delays removal of some empty
     directories.

DragonFly 6.5-DEVELOPMENT         August 1999        DragonFly 6.5-DEVELOPMENT