When I consider the snippet I don't understand it.
I know the following:

Code:

md5sum test.txt

That creates a hash and output it to the stdout

Code:

md5sum -c checkFile

That checks the signature for every hash/file in checkFile

--quiet is just a flag to suppress some verbosity

But what does md5sum test.txt --quiet -c checkFile do.

Creates a hash for test.txt and check the integrity of what every hash mentioned is in checkFile? I think not.

---------- Post updated at 06:41 PM ---------- Previous update was at 06:31 PM ----------

Never mind. I see what it is doing.
It takes test.txt and checkFile as hash-files because of the -c regardless of the position of the flag

---------- Post updated at 10:54 PM ---------- Previous update was at 06:41 PM ----------

Perhaps you might benefit of implementing your own md5checks using native perl instead of making a system call.

Here's a tiny example of how to check the sums of some files in test.md5
You need to have the module Digest::MD5
This can easily be modified to your needs; to make it quiet or to give you a true or false return

Code:

#!/usr/bin/perl

# Author: Aia
# Date: 5-22-2014
# check_md5.pl
# reads a md5 hash file pair formatted file and checks its sum

use strict;
use warnings;
use Digest::MD5 qw(md5_hex);

my $md5_file = "test.md5";
my %groups;  


open my $fh_in, '<', $md5_file or die "Can't open $md5_file: $!\n";
while (my $line = <$fh_in>) {
    chomp $line;
    my ($key, $value) = split(" ", $line);
    $groups{$key} = $value;
}

close ($fh_in);

for my $key (keys %groups) {
    open my $fh, '<', $groups{$key} or die "Can't open $groups{$key}: $!\n";
    binmode ($fh);
    my $md5 = Digest::MD5->new;
    $md5->addfile($fh);
    close ($fh);
    if (  $key eq $md5->hexdigest ) {
        print "$groups{$key}: OK\n";
    }
    else {
        print "$groups{$key}: FAILED\n";
    }
}