imv

#!/usr/bin/perl
# abstract: watch a dir and scp all created files therein to another host
use strict;
use Linux::Inotify2;
use Getopt::Long;

my $DEBUG = 0;

my $dest    = '/mnt/Music_3/.torrents/';
my $log     = "$ENV{HOME}/.mvtorrents.log";
my $pidfile = '/tmp/mvtorrents.pid';


GetOptions(
  k => \&killkid,
  d => \$DEBUG,
);

my $what = shift // "$ENV{HOME}/TorrentsToServer";

if(!-d $what) {
  print STDERR "$what is not a directory, bye\n";
  exit(1);
}

daemonize($log) unless($DEBUG);
watch($what);

sub watch {
  my $dir = shift;
  my $n = Linux::Inotify2->new;

  $n->watch($dir, IN_CREATE) or die($!);


  while(my @events = $n->read) {
    for my $event(@events) {
      sleep 2;
      if($event->{name} =~ m/\.torrent$/) {
        print localtime(time) . "\tIN_CREATE\t$event->{name} => $dest\n";
        system("scp -P 19216 $what/$event->{name} scp1\@192.168.1.128:$dest");
      }
    }
  }
  return 0;
}

sub daemonize {
  my $daemon_log = shift // '/dev/null';
  use POSIX 'setsid';
  my $PID = fork();
  exit(0) if($PID); #parent
  exit(1) if(!defined($PID)); # out of resources

  setsid();
  $PID = fork();
  exit(1) if(!defined($PID));

  if($PID) { # parent
    waitpid($PID, 0);
    unlink($pidfile); # remove the lock when child have died
    exit(0);
  }
  elsif($PID == 0) { # child
    open(my $fh, '>', $pidfile) or die("Cant open $pidfile: $!");
    print $fh $$;
    close($fh);
    open(STDOUT, '>', $daemon_log);
    open(STDERR, '>', '/dev/null');
    open(STDIN,  '<', '/dev/null');
  }
}

sub killkid {
  open(my $fh, '<', $pidfile) or print "imv is not running\n" and exit(1);
  my $target = <$fh>;
  close($fh);

  if(kill(9, $target)) {
    print "imv with PID $target terminated\n";
  }
  else {
    print "Could not kill $target: $!";
  }
  exit(0);
}