Question

I am trying to open multiple processes in a Perl script on Windows. Program structure would look some thing like this…

 my($chld1_out, $chld1_in);
   my($chld2_out, $chld2_in);
   my($chld3_out, $chld3_in);
   my @cmds1=();
   my @cmds2=();
   my @cmds3=();

    $pid1 = open2($chld1_out, $chld1_in, 'ex1.exe')or die $!;
    $pid2 = open2($chld2_out, $chld2_in, 'ex2.pl')or die $!;
    $pid3 = open2($chld3_out, $chld3_in, 'ex3.exe')or die $!;

   print $chld1_in $cmds1[0];
   print $chld2_in $cmds2[0];
   $op1=<$chld1_out>;
   $op2=<$chld2_out>;
   if ( $op1 == 'done' && $op1 != 'done')
   print $chld1_in $cmds1[0];
   elsif ( $op1 != 'done' && $op1 == 'done')
   print $chld2_in $cmds2[0];
   elsif ( $op1 == 'done' && $op1 == 'done')
   print $chld1_in $cmds1[1];
   print $chld2_in $cmds2[1];
   .....
   .....
   for loops and while loops..... to process with the data output... and do conditional programming. 
   close $pid1 or die $!;
    close $pid2 or die $!;
    close $pid3 or die $!;

If it does how can I execute the Perl script ( ex2.pl )
one way i know is
system($^X,”ex2.pl”,”arg”) ;

I would appreciate fro your help on this ASAP…

Thanks,

-Abishek

Answer 1

Probably not, “opening” a process for reading is usually a fork and a pipe behind the scenes. And fork-execs don’t work on Windows*.

For executing a Perl script, just do it.

do 'ex2.pl';

And if you want to pass args:

{   local @ARGV = qw<One Two Three>;
    do 'ex2.pl';
}

When ex2.pl wants to access @ARGV it will be ( 'One', 'Two', 'Three' ). Of course if you want to do any of the perl shorthand ARGV tricks, it’s better to localize the GLOB.

{ local *ARGV = [ qw<One Two Three> ]; ... }

* – I’ve long thought that a suitable workaround should be possible using Windows process structures which have a readable stdout and stderr, as a well as a writable stdin.