NAME¶

Dir::Purge - Purge directories to a given number of files.

SYNOPSIS¶

  perl -MDir::Purge -e 'purgedir (5, @ARGV)' /spare/backups
  use Dir::Purge;
  purgedir ({keep => 5, strategy => "by_age", verbose => 1}, "/spare/backups");
  use Dir::Purge qw(purgedir_by_age);
  purgedir_by_age (5, "/spare/backups");

DESCRIPTION¶

Dir::Purge implements functions to reduce the number of files in a directory according to a strategy. It currently provides one strategy: removal of files by age.

By default, the module exports one user subroutine: "purgedir".

The first argument of "purgedir" should either be an integer, indicating the number of files to keep in each of the directories, or a reference to a hash with options. In either case, a value for the number of files to keep is mandatory.

The other arguments are the names of the directories that must be purged. Note that this process is not recursive. Also, hidden files (name starts with a ".") and non-plain files (e.g., directories, symbolic links) are not taken into account.

All directory arguments and options are checked before anything else is done. In particular, all arguments should point to existing directories and the program must have read, write, and search (execute) access to the directories.

One additional function, "purgedir_by_age", can be exported on demand, or called by its fully qualified name. "purgedir_by_age" calls "purgedir" with the "by age" purge strategy preselected. Since this happens to be the default strategy for "purgedir", calling "purgedir_by_age" is roughly equivalent to calling "purgedir".

WARNING¶

Removing files is a quite destructive operation. Supply the "test" option, described below, to dry-run before production.

OPTIONS¶

Options are suppled by providing a hash reference as the first argument. The following calls are equivalent:

  purgedir ({keep => 3, test => 1}, "/spare/backups");
  purgedir_by_age ({keep => 3, test => 1}, "/spare/backups");
  purgedir ({strategy => "by_age", keep => 3, test => 1}, "/spare/backups");

All subroutines take the same arguments.

keep

The number of files to keep. A negative number will reverse the strategy. See option "reverse" below.

strategy

Specifies the purge strategy. Default (and only allowed) value is "by_age".

This option is for "purgedir" only. The other subroutines should not be provided with a "strategy" option.

include

If this is a reference to a subroutine, this subroutine is called with arguments ($file,$dir) and must return true for the file to be included in the list of candidates,

If this is a regular expression, the file file will be included only if the expression matches the file name.

reverse

If true, the strategy will be reversed. For example, if the strategy is "by_age", the oldest files will be kept instead of the newest files.

Another way to reverse the strategy is using a negative "keep" value. This is not unlike Perl's array subscripts, which count from the end if negative.

A negative "keep" value can be combined with "reverse" to reverse the reversed strategy again.

verbose

Verbosity of messages. Default value is 1, which will report the names of the files being removed. A value greater than 1 will produce more messages about what's going on. A value of 0 (zero) will suppress messages.

debug

For internal debugging only.

test

If true, no files will be removed. For testing.

EXPORT¶

Subroutine "purgedir" is exported by default.

Subroutine "purgedir_by_age" may be exported on demand.

Calling purgedir_by_age() is roughly equivalent to calling purgedir() with an options hash that includes "strategy =" "by_age">.

The variable $Dir::Purge::VERSION may be used to inspect the version of the module.

AUTHOR¶

Johan Vromans (jvromans@squirrel.nl) wrote this module.

COPYRIGHT AND DISCLAIMER¶

This program is Copyright 2000 by Squirrel Consultancy. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the terms of either: a) the GNU General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version, or b) the "Artistic License" which comes with Perl.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See either the GNU General Public License or the Artistic License for more details.