Perl Fork example 
  
 This examples fork 10 child processes. 
 It will wait for all childs to finish before exiting. 
  
 #!/usr/local/roadm/bin/perl 
  
 use strict; 
 use warnings; 
  
 print "Starting main program\n"; 
 my @childs; 
  
 for ( my $count = 1; $count <= 10; $count++) { 
         my $pid = fork(); 
         if ($pid) { 
         # parent    #print "pid is $pid, parent $$\n"; 
         push(@childs, $pid); 
         } elsif ($pid == 0) { 
                 # child 
                 sub1($count); 
                 exit 0; 
         } else { 
                 die "couldnt fork: $!\n"; 
         } 
  
  
  
 } 
  
 foreach (@childs) { 
          my $tmp = waitpid($_, 0); 
          print "done with pid $tmp\n";  ### DONE WITH HTTP CHILD 
  
 } 
  
 print "End of main program\n"; ### RETURN DATA FOR ALL 10 CHILDREN 
  
  
 sub sub1 { 
         my $num = shift; 
         print "started child process for  $num\n"; ### Make my HTTP CALL HERE 
         sleep $num; 
         print "done with child process for $num\n"; ### Return Data for 1 HTTP CHILD 
         return $num; 
 } 
  
  
 Output looks like: 
  
 Starting main program 
 started child process for  1 
 started child process for  2 
 started child process for  3 
 started child process for  4 
 started child process for  5 
 started child process for  6 
 started child process for  9 
 started child process for  10 
 started child process for  7 
 started child process for  8 
 done with child process for 1 
 done with pid 5584 
 done with child process for 2 
 done with pid 5585 
 done with child process for 3 
 done with pid 5586 
 done with child process for 4 
 done with pid 5587 
 done with child process for 5 
 done with pid 5588 
 done with child process for 6 
 done with pid 5589 
 done with child process for 7 
 done with pid 5590 
 done with child process for 8 
 done with pid 5591 
 done with child process for 9 
 done with pid 5593 
 done with child process for 10 
 done with pid 5594 
 End of main program 
  
 Another Version of doing this without fork is below.:: 
 ------------------------------------------------------ 
 ---------------------------------------------------- 
 Below you'll find an example of a multi-threaded Perl program as well as a forked Perl program. 
 Both seem to work fine. A disadvantage of threads is that Perl needs to be compiled with threads support. 
 Not all versions of Perl come with that by default. 
 A Perl Thread example 
  
 #!/usr/local/roadm/bin/perl 
 # This is compiled with threading support 
  
 use strict; 
 use warnings; 
 use threads; 
 use threads::shared; 
  
 print "Starting main program\n"; 
  
 my @threads; 
 for ( my $count = 1; $count <= 10; $count++) { 
         my $t = threads->new(\&sub1, $count); 
         push(@threads,$t); 
 } 
 foreach (@threads) { 
         my $num = $_->join; 
         print "done with $num\n"; 
 } 
 print "End of main program\n"; 
  
 sub sub1 { 
         my $num = shift; 
         print "started thread $num\n"; 
         sleep $num; 
         print "done with thread $num\n"; 
         return $num; 
 } 
  
 Will print: 
  
 Starting main program 
 started thread 1 
 started thread 2 
 started thread 3 
 started thread 4 
 started thread 5 
 started thread 6 
 started thread 7 
 started thread 8 
 started thread 9 
 started thread 10 
 done with thread 1 
 done with 1 
 done with thread 2 
 done with 2 
 done with thread 3 
 done with 3 
 done with thread 4 
 done with 4 
 done with thread 5 
 done with 5 
 done with thread 6 
 done with 6 
 done with thread 7 
 done with 7 
 done with thread 8 
 done with 8 
 done with thread 9 
 done with 9 
 done with thread 10 
 done with 10 
 End of main program