wallpaper_daemon

#!/usr/bin/perl
# vim:ft=perl:
# abstract: changes background on htpc connected tv every $sleep seconds
use strict;
use warnings FATAL => 'all';
use vars qw($VERSION);
use List::Util ();

my $sleep = 15;
my @walls = List::Util::shuffle(
  glob("$ENV{HOME}/wallpapers/HD/*"),
);

daemonize();

while(1) {
  system('feh', '--bg-center', $walls[ int(rand(scalar @walls ))]);
  sleep $sleep;
}

sub daemonize {
  my $daemon_log = shift // q{/dev/null};
  use POSIX q{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);
    exit(0);
  }
  elsif($PID == 0) { # child
    open(STDOUT, q{>}, $daemon_log);
    open(STDERR, q{>}, q{/dev/null});
    open(STDIN,  q{<}, q{/dev/null});
  }
}