File versioning

I wrote a small script to do file-level backup/versioning of a single file or group of files as a whole, without resorting to anything beyond basic cp, tar and rm.

Basically it works like this:



$ versionbackup.sh -h
versionbackup.sh -h -v -b backups | -r retdays [-d dateargs] [-m middlechar] [-p prefixchar]
    [-r retention] [-s suffixchar] [-t tarball] file ...

  -b numbaks    sets the number of backups to keep (copies retention)
  -d dateformat a string to be passed verbatim to the date command. Beware!
                in this case, if you omit time in a resolution high enough
                you could end _overwriting_ files! Example, if you rotate
                the files hourly and don't specify an hour in the date string,
                but only the day, you'll end up overwriting the same file 23
                times a day... better not to use this option if you are not
                sure. Note than in this case, -m is ignored.
  -m middle     sets the middle char
  -p prefix     sets the prefix char
  -r daysago    keeps files newer than daysago days (time retention)
  -s suffix     sets the suffix char
  -t tarball    creates a tarball of the input files and rotate this instead
          for convenience, the tar is automatically .gz compressed
  -v            verbose, echo every operation, including option parsing
                (useful to debug command-line options)

It should work nicely on any variant of unix (tested on linux and MacOSX).

I'll find some place to post the source and link it back here.