use strict;
use warnings;

use IPC::Run qw( run ) ;

sub process_stdout {
   my ($fh) = @_;
   local *_;  # Protect caller's $_
   while (<$fh>) {
      chomp;
      print("[out:$_]\n");
   }
}

sub process_stderr {
   my ($fh) = @_;
   local *_;  # Protect caller's $_
   while (<$fh>) {
      chomp;
      print("[err:$_]\n");
   }
}

{
   # User-defined
   my $module = "mymodule";
   my $OLD    = "1.41";
   my $NEW    = "1.42";
   my @cmd    = ( 'cvs', 'rlog', "-r${OLD}::${NEW}" '-SN', $module );

   my $cvs_in  = '';
   my $cvs_out = '';
   my $cvs_err = '';

   run \@cmd, \$cvs_in, \$cvs_out, \$cvs_err
      or die("Unable to launch CVS\n");

   {
      # Requires Perl 5.8.
      # In Perl 5.6, use IO::Scalar
      # or work with $csv_out directly.
      use 5.008000;
      open(my $fh, '<', \$cvs_out);
      process_stdout($fh);
   }

   {
      # Requires Perl 5.8.
      # In Perl 5.6, use IO::Scalar
      # or work with $csv_err directly.
      use 5.008000;
      open(my $fh, '<', \$cvs_err);
      process_stderr($fh);
   }
}