#!/usr/bin/perl
use warnings;
use strict;
use Parallel::ForkManager;

my $dir = shift || '.';
my @dirs =  get_sub_dirs($dir);

my $max_tasks   = 3;
my $pm = new Parallel::ForkManager($max_tasks);
$|++;
my $start = time();

for my $dir (@dirs) {
    my $pid = $pm->start and next;
    printf "Begin processing $dir at %d secs.....\n", time() - $start;
    
    #push all the $dir/files into @ARGV and search through them 
    #line by line
    
    @ARGV = <$dir/*>;
    
     while (<ARGV>) {
        close ARGV if eof;
       #find some search term, using "perl" for example  
       if( $_ =~ /perl/)
        {
           print "$ARGV: $. :$_\n";
           $pm->finish;
           goto END;
        }               
     }    
    END:
    printf ".... $dir done at %d secs!\n", time() - $start;
    $pm->finish;
}

print " all done\n";
exit;

##########################################################
sub get_sub_dirs {
 my $dir = shift;
 opendir my $dh, $dir or die "Error: $!";
 
 my @dirs = grep { -d $_ } readdir $dh;
 @dirs = grep !/^\.\.?$/, @dirs;
 closedir $dh;
 return @dirs;
}