gistfile1.txt

#!/usr/bin/env perl
#
# Filesystem changes trigger

use v5.14;
use FindBin;
use lib "$FindBin::Bin/../lib";
use E1::Setup::Perl;
use Filesys::Notify::Simple;

$|++;

my ($dir, @cmd) = @ARGV;
die("FATAL: '$dir' is not a valid directory\n") unless -d $dir;
die("FATAL: need a command to run\n") unless @cmd;

my $watcher = Filesys::Notify::Simple->new([$dir]);

say "\n** Start waiting for changes to '$dir'";

$watcher->wait(
  sub {
    say "\n** Filesystem change detection:";
    say "    $_->{path}" for @_;

    say "\n** Executing command:";
    say "    @cmd";
    system(@cmd);

    my $path = "$FindBin::Bin/../.release";
    if (-f $path) {
      my $now = time;
      utime($now, $now, $path);
      say "\n** Updated $path timestamp\n";
    }
  }
) while 1;