Hi,
the following script is sorting MD5 checksum files after filename. If only one filename is given the sorted result is written back to the input file.

Also works with SHA1 checksum files or similar. 

use strict;
use warnings;

my $infile;
my $outfile;

if (!@ARGV or grep /-h|--help/, @ARGV) {
    print STDERR "Usage: sortmd5 <md5sum file>\n";
    print STDERR "   or  sortmd5 <md5sum infile> <md5sum outfile>\n\n"
+;
    print STDERR "First usage changes md5sum file inplace. The string 
+'-' can ",
                 "be given to specify STDIN or STDOUT.\n";
    exit 1;
}

if (@ARGV) {
    $infile  = $ARGV[0] unless $ARGV[0] eq '-';
    $outfile = (@ARGV > 1) ? $ARGV[1] : $ARGV[0];
    undef $outfile if $outfile eq '-';
}

open (STDIN, '<', $infile) if defined $infile;

my %md5;
my $badline = 0;

while (<STDIN>) {
    if (/^([a-f0-9]{32,} [* ])(.*)\z/si) {
        $md5{$2} = $1;
    }
    else {
        $_ =~ s/\r?\n?\z//;
        print STDERR "Found bad line: $_\n";
        $badline++ 
    }
}

close (STDIN);

rename ($infile, $infile . '.bak') if defined $infile and $badline;

{
no warnings;
open (STDOUT, '>', $outfile) if defined $outfile;
}

foreach my $file (sort keys %md5) {
    print "$md5{$file}$file";
}

exit 0;
__END__

[download]

In reply to sortmd5 script by mscharrer

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