SYNOPSIS

       fileprune  [-n|-N|-p]  [-c  count|-s  size[k|m|g|t]|-a  age[w|m|y]] [-e
       base|-g standard deviation|-f] [-t a|m|c] [-FK] file ...

DESCRIPTION

       Fileprune will delete files from the specified set  targeting  a  given
       distribution  of the files within time as well as size, number, and age
       constraints.  Its main purpose is to keep a set of daily-created backup
       files  in  manageable  size, while still providing reasonable access to
       older versions.  Specifying a size, file number, or age constraint will
       simply  remove  files starting from the oldest, until the constraint is
       met.  The distribution specification (exponential,  Gaussian  (normal),
       or  Fibonacci)  provides finer control of the files to delete, allowing
       the retention of recent copies and the increasingly aggressive  pruning
       of the older files.  The retention schedule specifies the age intervals
       for which files will be retained.  As an example, an exponential reten-
       tion schedule for 10 files with a base of 2 will be

              1 2 4 8 16 32 64 128 256 512 1024

       The  above  schedule  specifies that for the interval of 65 to 128 days
       there should be (at least) one retained file  (unless  constraints  and
       options  override this setting).  Retention schedules are always calcu-
       lated and evaluated in integer days.  By default  fileprune  will  keep
       the oldest file within each day interval allowing files to migrate from
       one interval to the next as time goes by.  It may also keep  additional
       files,  if  the  complete  file set satisfies the specified constraint.
       The algorithm used for pruning does not assume that the files are  uni-
       formly  distributed; fileprune will successfully prune file collections
       stored at irregular intervals.

OPTIONS

       -n     Do not delete  files;  only  print  file  names  that  would  be
              deleted.

       -N     Do  not  delete  files;  only  print  file  names  that would be
              retained.

       -p     Do not process files.  Print the specified  schedule  for  count
              elements.

       -c count
              Keep count files.

       -s size
              Keep  files  totaling size bytes.  The size argument can be fol-
              lowed by a k, m, g,  or  t  uppercase  or  lowercase  suffix  to
              express quantities from kilobytes to terabytes.

       -a age Keep  files  up  to  the specified age.  The age argument can be
              followed by a w, m, or y suffix to  specify  weeks,  months,  or
              int from a to b f(x) dx The standard deviation is  specified  in
              day  units;  as  a rule of a thumb the oldest file retained will
              have an age of twice the standard deviation.

       -f     Use a Fibonacci distribution  for  the  pruning  schedule.   The
              Fibonacci sequence starts with 1, 1, and each subsequent term is
              the sum of the two previous ones.

       -t a|fP|c
              For determining a file's age use its  access,  modification,  or
              creation time.  By default the modification time is used.

       -F     Force  file pruning even if the size or count constraint has not
              been exceeded.

       -K     Keep files scheduled in each pruning interval, even if the  size
              or count constraint has been exceeded.

EXAMPLE

       ssh remotehost tar cf - /datafiles >backup/`date +'%Y%m%d'`
       fileprune -e 2 backup/*
       Backup  remotehost,  storing  the  result  in a file named with today's
       timestamp (e.g. 20021219).  Prune the files in the backup directory  so
       that  each  retained  file's age will be double that of its immediately
       younger neighbor.

       fileprune -g 365 -c 30 *
       Keep at most 30 files with their ages  following  a  Gaussian  (normal)
       distribution with a standard deviation of one year.

       fileprune -e 2 -s 5G *
       Prune  the specified files following an exponential schedule so that no
       more than 5GB are occupied.  More than one  file  may  be  left  in  an
       interval,  if  the  size  constraint  is  met.  Alternatively, some old
       intervals may be emptied in order to satisfy the size constraint.

       fileprune -F -e 2 -s 5G *
       As above, but leave no more than one file in each scheduled interval.

       fileprune -K -e 2 -s 5G *
       As in the first example of the %g-constrained series, but leave exactly
       one  file  in  each  interval,  even if this will violate the size con-
       straint.

       fileprune -a 1m -f
       Delete all files older than one month use; use a Fibonacci distribution
       for pruning the remaining ones.

SEE ALSO

       newsyslog(8)



                                13 October 2003                   FILEPRUNE(1)