Perl Program/Script

# Perl Script to extract the 5 smallest timesteps from otf file
#
# Arguments: 1: otf filename

use strict;

# Test to see if there is an argument
if ($#ARGV < 0)
{
    print "No otf filename\n";
    exit;
}
# test to see if the otf file exists
if ( !(-e $ARGV[0]) )
{
    print "otf file $ARGV[0] does not exist\n";
    exit;
}
open (OTF, "< $ARGV[0]");
my $n;
my $t = 1.0e+20;
while ( <OTF>)
{
    if (/ (\d+) smallest timesteps/)
    {
         $n = $1;
         if ($n > 5) { $n = 5; }
         <OTF>;
         <OTF>;
         for (my $i=0; $i<$n; $i++)
         {
             $_ = <OTF>;
             print $_;
             my @f = split;
             if ($f[$#f] < $t) { $t = $f[$#f]; }
         }
         print "VAR TIMESTEP VALUE=\"$t\"\n";
         exit;
     }
}
close (OTF);