#!/usr/bin/perl

use warnings;
use strict;
use POSIX qw(_exit);

foreach my $mod (qw(CPAN No::Such IO::Socket Not::Installed))
{
  printf "%20s: %-3s\n",$mod,is_module_installed($mod)?"Yes":"No";
}


##</code><code>##

sub is_module_installed
{
  my($mod)=@_;
  return (system("perl -M$mod -e 1 2>/dev/null") == 0);
}

##</code><code>##

sub is_module_installed
{
  my($mod)=@_;
  defined(my $pid = fork)
    or die "Fork error: $!\n";
  if ($pid)
  {
    # Parent
    waitpid $pid,0;
    return $? == 0;
  }
  else
  {
    # Child
    close(STDERR);
    eval "use $mod;";
    _exit($@?1:0);
  }
}