09-04-2008
From the POSIX standards:
Quote:
4.7 File Times Update
Each file has three distinct associated time values: st_atime, st_mtime, and st_ctime. The st_atime field is associated with the times that the file data is accessed; st_mtime is associated with the times that the file data is modified; and st_ctime is associated with the times that the file status is changed. These values are returned in the file characteristics structure, as described in <sys/stat.h>.
st_atime == atime
st_ctime == ctime
st_mtime == mtime
Plus if you search the forum for file time you will find a lot of good information.
Broli - the definitions of these have been fixed for years - different apps do not violate those definitions. Things that can change mtime are opening a file for write/append or a call to utime() (e.g., touch). chmod or chown changes ctime, and utime or opening a file for read changes the atime. These values are NOT part of the file, they are file metadata maintained by the filesystem, as accessed thru the kernel.
Last edited by jim mcnamara; 09-04-2008 at 11:08 AM..
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LEARN ABOUT DEBIAN
tmpwatch
TMPWATCH(8) System Administrator's Manual TMPWATCH(8)
NAME
tmpwatch - removes files which haven't been accessed for a period of time
SYNOPSIS
tmpwatch [-u|-m|-c] [-MUadfqstvx] [--verbose] [--force] [--all]
[--nodirs] [--nosymlinks] [--test] [--fuser] [--quiet]
[--atime|--mtime|--ctime] [--dirmtime] [--exclude path]
[--exclude-user user] time dirs
DESCRIPTION
tmpwatch recursively removes files which haven't been accessed for a given time. Normally, it's used to clean up directories which are
used for temporary holding space such as /tmp.
When changing directories, tmpwatch is very sensitive to possible race conditions 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), will not switch filesystems,
skips lost+found directories owned by the root user, and only removes empty directories, regular files, and symbolic links.
By default, tmpwatch dates files by their atime (access time), not their mtime (modification time). If files aren't being removed when ls
-l implies they should be, use ls -u to examine their atime to see if that explains the problem.
If the --atime, --ctime or --mtime options are used in combination, the decision about deleting a file will be based on the maximum of
these times. The --dirmtime option implies ignoring atime of directories, even if the --atime option is used.
The time parameter defines the threshold for removing files. If the file has not been accessed for time, the file is removed. The time
argument is a number with an optional single-character suffix specifying the units: h for hours, d for days. If no suffix is specified,
time is in hours.
Following this, one or more directories may be given for tmpwatch to clean up.
OPTIONS
-u, --atime
Make the decision about deleting a file based on the file's atime (access time). This is the default.
Note that the periodic updatedb file system scans keep the atime of directories recent.
-m, --mtime
Make the decision about deleting a file based on the file's mtime (modification time) instead of the atime.
-c, --ctime
Make the decision about deleting a file based on the file's ctime (inode change time) instead of the atime; for directories, make
the decision based on the mtime.
-M, --dirmtime
Make the decision about deleting a directory based on the directory's mtime (modification time) instead of the atime; completely
ignore atime for directories.
-a, --all
Remove all file types, not just regular files, symbolic links and directories.
-d, --nodirs
Do not attempt to remove directories, even if they are empty.
-f, --force
Remove files even if root doesn't have write access (akin to rm -f).
-l, --nosymlinks
Do not attempt to remove symbolic links.
-q, --quiet
Report only fatal errors.
-s, --fuser
Attempt to use the "fuser" command to see if a file is already open before removing it. Not enabled by default. Does help in some
circumstances, but not all. Dependent on fuser being installed in /sbin. Not supported on HP-UX or Solaris.
-t, --test
Don't remove files, but go through the motions of removing them. This implies -v.
-U, --exclude-user=user
Don't remove files owned by user, which can be an user name or numeric user ID.
-v, --verbose
Print a verbose display. Two levels of verboseness are available -- use this option twice to get the most verbose output.
-x, --exclude=path
Skip path; if path is a directory, all files contained in it are skipped too. If path does not exist, it must be an absolute path
that contains no symbolic links.
SEE ALSO
cron(1), ls(1), rm(1), fuser(1)
WARNINGS
GNU-style long options are not supported on HP-UX.
AUTHORS
Erik Troan <ewt@redhat.com>
Preston Brown <pbrown@redhat.com>
Nalin Dahyabhai <nalin@redhat.com>
Miloslav Trmac <mitr@redhat.com>
4th Berkeley Distribution Fri Dec 14 2007 TMPWATCH(8)