1: #!/usr/local/bin/perl
    2: 
    3: ($#ARGV == 1) || die "usage: cmp.pl <file1> <file2>\n";
    4: 
    5: open(IN0,"<$ARGV[0]") || die "unable to open $ARGV[0]\n";
    6: open(IN1,"<$ARGV[1]") || die "unable to open $ARGV[1]\n";
    7: binmode IN0;
    8: binmode IN1;
    9: 
   10: $tot=0;
   11: $ret=1;
   12: for (;;)
   13:         {
   14:         $n1=sysread(IN0,$b1,4096);
   15:         $n2=sysread(IN1,$b2,4096);
   16: 
   17:         last if ($n1 != $n2);
   18:         last if ($b1 ne $b2);
   19:         last if ($n1 < 0);
   20:         if ($n1 == 0)
   21:                 {
   22:                 $ret=0;
   23:                 last;
   24:                 }
   25:         $tot+=$n1;
   26:         }
   27: 
   28: close(IN0);
   29: close(IN1);
   30: if ($ret)
   31:         {
   32:         printf STDERR "$ARGV[0] and $ARGV[1] are different\n";
   33:         @a1=unpack("C*",$b1);
   34:         @a2=unpack("C*",$b2);
   35:         for ($i=0; $i<=$#a1; $i++)
   36:                 {
   37:                 if ($a1[$i] ne $a2[$i])
   38:                         {
   39:                         printf "%02X %02X <<\n",$a1[$i],$a2[$i];
   40:                         last;
   41:                         }
   42:                 }
   43:         $nm=$tot+$n1;
   44:         $tot+=$i+1;
   45:         printf STDERR "diff at char $tot of $nm\n";
   46:         }
   47: exit($ret);