######################################################################

File::Tail::FAM 0.02
######################################################################

NAME

File::Tail::FAM - Tail using the File Alteration Monitor (FAM)

SYNOPSIS

use File::Tail::FAM;

        my $tail = File::Tail::FAM->new(
            file => "/tmp/abc"
        );

           # Blocking read (without wasting any CPU time)
        while(defined( my $data = $tail->read() )) {
            print "This just got added: [$data]\n";
        }

           # Or, read data in non-blocking mode
        my $data = $tail->read_nonblock();
        if(defined $data) {
            print "This just got added: [$data]\n";
        } else {
            print "Nothing happened\n";
        }

DESCRIPTION

"File::Tail::FAM" reports when new data chunks are appended to a given file. Similar to the Unix command

$ tail -f filename

it watches a file grow continuously and reports whenever a new chunk of data has been added.

Differently from the traditional approach of periodically polling the file (used by "tail -f" and "File::Tail"), "File::Tail::FAM" uses the File Alteration Monitor to get notified by the Linux kernel whenever new data gets added to the watched file.

This way, "File::Tail::FAM" will simply block (and therefore won't use any CPU cycles) until the kernel's notification mechanism wakes it up when new data has arrived.

"File::Tail::FAM" uses the Perl module "SGI::FAM", which provides an API to the File Alteration Monitor (FAM) library routines which come with many Linux distributions ("man 3 fam") and are available for download at

http://oss.sgi.com/projects/fam/index.html

LEGALESE

Copyright 2005 by Mike Schilli, all rights reserved. This program is free software, you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR

2005, Mike Schilli <cpan@perlmeister.com>