NAME

"File::StatCache" - a caching wrapper around the "stat()" function

DESCRIPTION

This module implements a cache of information returned by the "stat()" function. It stores the result of a "stat()" syscall, to avoid putting excess load on the host's filesystem in case many calls would be generated.

By default the cache for any given filename will time out after 10 seconds; so any request for information on the same name after this time will result in another "stat()" syscall, ensuring fresh information. This timeout is stored in the package variable $File::StatCache::STATTIMEOUT, and can be modified by other modules if required.

FUNCTIONS
$stats = get_stat( $path [, $now ] )
This function wraps a call to "File::stat::stat()", and caches the result. If the requested file was "stat()"ed within $STATTIMEOUT seconds, it will not be requested again, but the previous result (i.e. an object reference or "undef") will be returned.

The $now parameter allows some other time than the current time to be used, rather than re-request it from the kernel using the "time()" function. This allows a succession of tests to be performed in a consistent way, to avoid a race condition.

$path The path to the filesystem item to "stat()"

$now Optional. The time to consider as the current time

$stats = stat( $path )
@stats = stat( $path )
This is a drop-in replacement for either the perl core "stat()" function or the "File::stat::stat" function, depending whether it is called in list or scalar context. It behaves identically to either of these functions, except that it returns cached results if the cached value is recent enough.

Note that in the case of failure (i.e. "undef" in scalar context, empty in list context), the value of $! is not reliable as the reason for error. Error results are not currently cached.

$path The path to the filesystem item to "stat()"

get_item_mtime( $path [, $now ] )
This function is equivalent to

(scalar get_stat( $path, $now ))->mtime

$path The path to the filesystem item to "stat()"

$now Optional. The time to consider as the current time

LIMITATIONS

• The shortcut tests (e.g. "-f", "-r", etc..) will not work with this module.
• The "last results" filename "_" cannot be used; the following code will not work with this module:

my @stats = stat( _ );

BUGS

• The value of $! is not preserved for per-file failures. When "undef" or the empty list are returned, the $! value may not indicate the reason for this particular failure.

AUTHOR

Paul Evans <leonerd@leonerd.org.uk>