poll

inotify.pl

#!/usr/bin/env perl

use Linux::Inotify2;

my $filename = $ARGV[0] or die "need a filename";

# create a new object
my $inotify = new Linux::Inotify2 or die "unable to create new inotify object: $!";

# add watchers
$inotify->watch ($filename, IN_CLOSE_WRITE, sub {
   my $e = shift;
   my $name = $e->fullname;
   print "write to $name\n";
});

# manual event loop
1 while $inotify->poll;

procedural.pl

#!/usr/bin/env perl

use File::stat qw/stat/;

my $filename = $ARGV[0] or die "missing filename";

my $last;

$last = stat($filename)->mtime;
while (1) {
    my $this = stat($filename)->mtime;
    print "write to $filename\n" if $this != $last;
    $last = $this;
    sleep 1;
}

watchdir.pl

#!/usr/bin/env perl

use Linux::Inotify2;

my $dirname = $ARGV[0] or die "need a dirname";

# create a new object
my $inotify = new Linux::Inotify2 or die "unable to create new inotify object: $!";

# add watchers
$inotify->watch ($dirname, IN_MOVED_TO,
  sub {
   my $e = shift;
   my $name = $e->fullname;
   print "new file $name was moved into $dirname\n";
});

# manual event loop
1 while $inotify->poll;