1 #! /usr/bin/perl

     2 use 5.014;

     3 use strict;

     4 use warnings;

     5 

     6 my $BS = 4 * 4096;

     7 

     8 die "Usage: $0 INFILE OUTDEV\n" unless @ARGV == 2;

     9 

    10 my ($inf, $outf) = @ARGV;

    11 

    12 my $in;

    13 

    14 if ($inf eq '-') { open($in, '<&STDIN') or die "$0: Can't open <&STDIN: $!\n" }

    15 else { open($in, '<', $inf) or die "$0: Can't open <$inf: $!\n" }

    16 

    17 open(my $out, '+<', $outf) or die "$0: Can't open +>$outf: $!\n";

    18 

    19 $/ = \$BS;

    20 

    21 {

    22     my ($read, $skipped, $written) = (0, 0, 0);

    23     my $t0 = time;

    24 

    25 while (defined ($_ = <$in>)) {

    26     ++$read;

    27 

    28     my $lastpos = tell $out;

    29     my $block = <$out>;

    30 

    31     if (defined $block and $block eq $_) {

    32 	++$skipped;

    33 	next;

    34     }

    35 

    36     seek($out, $lastpos, 0) or die "$0: Can't seek: $!\n";

    37     print {$out} $_;

    38 

    39     ++$written;

    40 

    41 } continue {

    42     my $dt = time - $t0;

    43     printf "\rskipped: %5.1fM, written: %5.1fM written, speed: %5.1fM/s", 

    44 	    $skipped * $BS / 2**20, 

    45 	    $written * $BS / 2**20, 

    46 	    $dt ?  $read * $BS / 2**20 / $dt : 0;

    47 }

    48 

    49     say "\nDONE";

    50 

    51 }