man > tmpreaper(8)

TMPREAPER(8)                           System Manager's Manual                          TMPREAPER(8)

NAME
       tmpreaper - removes files which haven't been accessed for a period of time

SYNOPSIS
       tmpreaper  [-htvfmMsaT]  [--help]  [--test]  [--verbose]  [--force] [--delay=x] [--runtime=x]
       [--showdeleted]  [--ctime]   [--mtime]   [--mtime-dir]   [--symlinks]   [--all]   [[--protect
       '<shell_pattern>']...]  <time_spec> <dirs>...


DESCRIPTION
       tmpreaper recursively searches for and removes files and empty directories which haven't been
       accessed  for  a  given number of seconds.  Normally, it's used to clean up directories which
       are used for temporary holding space, such as "/tmp".  Please read the  WARNINGS  section  of
       this manual.

       When  changing  directories,  tmpreaper is very sensitive to possible race condition security
       exploits[1], and will exit with an error if one is detected.  It  does  not  follow  symbolic
       links  in  the  directories it's cleaning (even if a symbolic link is given as its argument),
       never performs chdir(".."), will not switch file systems, and only removes empty  directories
       and  regular  files. Unless your machine is one with lots of relatively untrusted users, such
       as an ISP or school, you don't need this program; `find ... -exec rm ...' works just as  well
       when you don't have to be concerned about people trying to exploit the race condition on you.

       tmpreaper  will  stop  itself after almost one minute with an appropriate warning message, as
       attempts to keep it running long enough so that it runs in parallel with another instance  of
       itself  may also lead to possible vulnerabilities. Normally, tmpreaper won't need that amount
       of time.  If your system is so slow that it does,  try  to  configure  things  so  that  this
       doesn't  happen.  As  a  last resort, the --runtime=x option can be used to set the number of
       seconds after which the timeout occurs; the default setting is 55 seconds.

       tmpreaper dates files by their atime, not their mtime, unless you select the --mtime  option.
       If files aren't being removed when ls -l implies they should be, use stat(1) or ls --time=ac‐
       cess to examine the file's atime and see if that helps to explain the problem.

       Additionally,  tmpreaper  can be instructed to also check the ctime (inode change time, which
       is updated e.g. when the file is created or permissions are changed). This is primarily  use‐
       ful  when tmpreaper is used to clean up directories that are accessible as a Samba share; DOS
       (and Windows) PCs preserve the mtime and the atime when copying to a new file, so that it ap‐
       pears that the newly created file is old.  tmpreaper will remove such files if the  atime  is
       beyond  the  removal  time,  even though they were just created. This is avoided by using the
       --ctime option.

       As testing the contents of subdirectories will update those directories' atime, empty  direc‐
       tories won't be removed. To circumvent this problem you can use the --mtime-dir option, which
       will  switch on mtime checking for directories only. Using --mtime-dir in addition to --mtime
       doesn't do anything useful.

       The <time_spec> parameter defines the age threshold for removing files. If the file  has  not
       been  accessed for <time_spec>, it becomes eligible for removal.  The <time_spec> should be a
       number, defaulting to hours, optionally suffixed by one character:  `d'  for  days,  `h'  for
       hours,  `m' for minutes, or `s' for seconds.  Following the time option, one or more directo‐
       ries must be given for tmpreaper to clean up.

       On linux ext2/ext3/ext4 filesystems, no errors will be given  when  trying  to  remove  files
       marked  as  immutable. A common situation for this was the ext3 .journal file. However, there
       may of course be other files marked as such by the system administrator.


OPTIONS
       <noargs>, -h, --help
              Print a brief version, copyright, and usage statement on stderr, then exit with  error
              status 1.


       -t, --test
              Don't  actually remove any files, but go through the motions, checking through the di‐
              rectory, then pretend to remove the eligible files.


       -v, --verbose
              Print a verbose display. Two levels of verbosity are available---use this option twice
              to get the most verbose output.  The --test option automaticly sets --verbose once.
              Higher numbers mean more output (max. is 3).
              To force normal verbosity after --test, use "--verbose=0".  This will  generally  only
              show error messages. Use "--test --verbose=0 --showdeleted" to give a shellscript-like
              list of actions that would have been done (see the --showdeleted description below).


       --showdeleted
              Show  what  files and directories are deleted. The output is in the form of shell com‐
              mands, i.e. "rm /dir/dir2/file" and "rmdir /dir/dir2".
              When used together with --test, this option will still cause the "shell  commands"  to
              be printed, although nothing is really done. Note that this may show more than without
              --test, as problems removing the file won't be detected (e.g. immutable files).


       -f, --force
              Remove  files even if EUID doesn't have write access (akin to rm -f).  Normally, files
              owned by the current EUID, with no write bit set are not removed.


       --delay=x
              Delay execution at the start for a random time, up to x seconds; if no value is speci‐
              fied, the default maximum time to delay is 256 seconds.  This is an option  useful  in
              cron scripts to make the execution of tmpreaper less predictable, thus making things a
              little harder for those who would attempt to use tmpreaper to thwart security.


       -T x, --runtime=x
              Execution  of  tmpreaper will aborted after x seconds; this is to prevent attacks that
              create many, many files.  By default the timeout is set to 55 seconds.  A value  of  0
              will  disable  this  feature,  which  is not advised as this feature prevents possible
              race-conditions between different instances of tmpreaper.


       -m, --mtime
              Base the decision of whether to remove the file on  its  mtime,  rather  than  on  its
              atime.


       -M, --mtime-dir
              Base  the decision of whether to remove the directory on its mtime, rather than on its
              atime.


       -c, --ctime
              Base the decision of whether to remove the file on  its  ctime,  in  addition  to  its
              atime.  Only applicable if the --mtime options is not given!


       -s, --symlinks
              Remove symlinks too, not just regular files and directories.


       -a, --all
              Remove all file types, not just regular files, symlinks, and directories.


       --protect '<shell_pattern>'
              Protect  the  files  that match the <shell_pattern> from deletion.  This option may be
              used more than once.  It has no one letter abbreviation, you must spell out  the  full
              word "protect".

              If you do not enclose the <shell_pattern> in single quotes, the shell will perform the
              expansion  before  tmpreaper  reads  its argument array.  The program does not support
              that syntax, so you must use single quotes around the glob pattern.

              tmpreaper will chdir(2) into each of the directories you've specified for cleanup, and
              check for files matching the <shell_pattern> there.  It then builds a  list  of  them,
              and uses that to protect them from removal.  For example:

              tmpreaper --test --verbose --protect \
               '.X*-{lock,unix,unix/*}' --protect '.ICE-{unix{/*,}}' \
               5d /tmp  # 5 day grace period


TIPS
       As  long as there are files present inside a subdirectory, it won't get removed.  You can use
       a non-writable, self-owned file, perhaps named ".tmpreaper", or, if you are su, a  file  that
       has  the  ext2fs  immutable  attribute  set,  to  keep a subdirectory from being deleted.  Of
       course, you could just as easily use use the --protect option to obtain the same result.

       Because the command line argument processing is implemented with GNU  getopt_long(3)[2],  you
       may order the arguments thusly, if it pleases you:

       tmpreaper --test --verbose 5h \
        --protect './tmp/{blah?,dir{/blah4,}}' ./tmp \
        --protect '/tmp/.X*' /tmp

        ...  Note that if you use --all or --symlinks, it will have global effect.  If you only want
       it turned on for one directory, you must use separate commands.


WARNINGS
       Please do not ever run tmpreaper on `/'!!! There are no safeguards against  this  built  into
       the program, because that would make it difficult to use in a chrooted environment.



SEE ALSO
       chattr(1) chdir(2) chroot(8) cron(1) getopt_long(3) ls(1) lsattr(1) rm(1) stat(1)

       [1]  http://seclists.org/lists/bugtraq/1996/May/0046.html or
            http://www.security-express.com/archives/bugtraq/1996_2/0054.html

            http://linuxgazette.net/18/tmp.html
            (formerly http://www.linuxgazette.com/issue18/tmp.html)

            http://linuxgazette.net/20/followup.html

       [2] info:(libc)Long Options


AUTHOR
           Karl M. Hegbloom <karlheg AT debian.org>

       Mostly based on `tmpwatch-1.2/1.4', by:
           Erik Troan <ewt AT redhat.com>

       Now being maintained for Debian by:
           Paul Slootman <paul AT debian.org>

4th Berkeley Distribution                  Sat Jan  5 2019                              TMPREAPER(8)