system("command &");

##</code><code>##

my $pid;
if (defined ($pid=fork)) {
  if (!$pid) {
    # Execute command in the child
    exec ("command");
    # If it returns, there was an error
    die "Error executing command: $!\n";
  }
  # The parent continues unaffected, falls of the if stmt
}
else {
  die "Error in fork: $!\n";
}