Ubuntu Manpage: tmpreaper - removes files which haven't been accessed for a period of time

Provided by: tmpreaper_1.6.13+nmu1+deb9u1build0.18.04.1_amd64

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=access 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 useful 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 appears that the newly created file is old.
tmpreaper will remove such files is 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 directories 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 directories 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 directory, 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 commands, 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 specified, 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.

AUTHOR

           Karl M. Hegbloom <karlheg@debian.org>

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

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

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