file watching in a directory using perl - perl

Question

i need to watch files that fall under a directory.I have coded the below script in perl . but it is not doing what i want .
whenever a file or files arrives , it has to do a movement .
And then it has to keep watching files again.
the script should be running in background.
#!/usr/bin/perl
use warnings;
use File::Copy qw(move);
$src_dir = '/root/prasanna/dir';
$tgt_dir = '/root/prasanna/dir/dir1';
while (true) {
opendir( DIR, "/root/prasanna/dir" )
or die "Cannot open /root/prasanna/dir: $!\n";
my #Dircontent = readdir DIR;
close DIR;
my $items = #Dircontent;
if ( $items > 2 ) {
print "files available";
while ($items) {
print $items;
move $src_dir. '/' . $items, $tgt_dir . '/' . $items;
unlink $items;
}
}
else { sleep 50; }
}
The problem with the above code is
1. the if statement keeps on printing the 'files available' . goes on infinite loop , it doesnt watch for files again .even if i do operations on file, i dont knw how to make it look for files again.
2. the script doesnt run in background .
any help is highly appreciated . thanks beforehand.!

Answer 1

presuming you are running under Linux, use Linux::Inotify2...
use Linux::Inotify2;
# create an Inotify object
my $Inotify = Linux::Inotify2->new() or die "Fail: $!";
# choose which operations for which you wish to be notified
my $watchme = IN_CLOSE_WRITE | IN_CREATE | IN_MOVED_TO; # defined and exported
$Inotify->watch('/root/prasanna/dir', $watchme, \&watcher) or die "Fail: $!";
while (1) {
$Inotify->poll;
}
sub watcher
{
# do something here
}
Note it can only monitor local filesystems (i.e. no NFS mounts)