NAME
File::CacheDir - Perl module to aid in keeping track and cleaning up
files, quickly and without a cron $Id: CacheDir.pod,v 1.2 2001/06/11
17:01:36 earl Exp $
SYNOPSIS
CacheDir takes up to three parameters and returns a fully qualified
filename. Cool part is that it quickly and automatically cleans up files
that are too old.
ARGUMENTS
The possible named arguments (which can be named or sent in a hash ref,
see below for an example) are,
filename - which is what you want the file without the directory to be
named, like "storebuilder" . time . $$ I would suggest using a script
specific word (like the name of the cgi), time and $$ (which is the pid
number) in the filename, just so files are easy to track and the
filenames are pretty unique
ttl - how long you want the file to stick around can be given in seconds
(3600) or like "1 hour" or "1 day" or even "1 week"
base_dir - the base directory, like /tmp
CODE REF OVERRIDES
Most of the time, the defaults will suffice, but by having code refs in
your object, you can override most everything CacheDir does. To how the
code refs are used, I walk through the code with a simple example.
my $cache_dir = new File::CacheDir({ base_dir => '/tmp/example', ttl =>
'2 hours', filename => 'example.' . time . ".$$", });
An object gets created, with the hash passed getting blessed in.
my $filename = $cache_dir->cache_dir;
The ttl gets converted to seconds, here 7200. The
$ttl_dir = $base_dir . $ttl;
In our example, $ttl_dir = "/tmp/example/7200";
$self->{ttl_mkpath} - if the ttl directory doesn't exist, it gets made
with this code ref
Next, the number of ttl units since epoch, here it is something like
137738. This is
$self->{int_time} = int(time/$self->{ttl});
Now, the full directory can be formed
$dir = $ttl_dir . $self->{int_time};
If $dir exists, $dir . $self->{filename} gets returned. Otherwise, I
look through the $ttl_dir, and for each directory that is too old (more
than two units away) I run
$self->{cleanup} - just deletes the old directory, but this is where a
backup could take place, or whatever you like
Finally, I
$self->{sub_mkdir} - makes the new directory, $dir
and return the $filename
SIMPLE EXAMPLE
#!/usr/bin/perl -w
use strict;
use File::CacheDir qw(cache_dir);
my $filename = cache_dir({
base_dir => '/tmp',
ttl => '2 hours',
filename => 'example.' . time . ".$$",
});
