#!/usr/bin/perl

if ($#ARGV != 0) { 
  print "Usage: cksum fname\n";
  exit 1;
} 

# checksum computation taken from page 198 of Wall and 
# Schwartz's "Programming Perl"
open(TMPFILE, "< $ARGV[0]");
undef $/;
$sum = unpack("%32C*", <TMPFILE>) % 32767;
close(TMPFILE);
print "Checksum is $sum\n";
exit 0;