my_md5sum:

monty@work.mysql.com

mwagner@cash.mwagner.org

mwagner@evoq.mwagner.org

mwagner@here.mwagner.org

mwagner@work.mysql.com

mysqldev@build.mysql2.com

nick@mysql.com

#!/usr/bin/perl

#

# my_md5sum

#

# Script to clone the 'md5sum' command found on modern systems, since that

# command is not always found on all systems.

#

# Use the "--help" option for more info!

#

# Written by Matt Wagner <matt@mysql.com>

#

use strict;

use Digest::MD5;

use Getopt::Long;

my $VER= "1.0";

#

# Strip the leading path info off the program name ($0). We want 'my_md5sum'

# not './my_md5sum'.

#

$0=~ s/^.*\/(.+)$/$1/;

my ($opt_check, $opt_help)= undef;

GetOptions(

	"check|c" => \$opt_check,

	"help|h" => \$opt_help,

	) || usage(); 

#

# Put all the [file1 file2 file3 ...]'s into an array

#

my @files = @ARGV;

#

# Give the "--help" text if:

#  - "--help|-h" was specified

#  - The number of files given as arguments is nil

#  - The "--check|-c" option is used with more than one [file] argument

#

usage() if $opt_help || $#files == -1 || ($opt_check && $#files > 0);

# If "--check|-c", then go into checking

if ($opt_check)

{

	open (CHECKFILE, $files[0]) or die "$files[0]: $!";

	while (<CHECKFILE>)

	{

		#

		# Goto the next line in the file if it does not match a typical

		# digest line like:

		#

		# f1007efa2c72daa693981ec764cdeaca  Bootstrap

		#

		next if $_!~ m/^([a-z0-9]{32})\s+(.+)$/;

		# Collect the trappings from the above regex

		my $checksum= $1;

		my $checkfile= $2;

		# Generate a fresh MD5 for the file in question

		my $digest= &mkmd5($checkfile);

		# Check the fresh MD5 against what is recorded in the file

		# Print an error message if they don't match

		print "$0: MD5 check failed for '$checkfile'\n" if $digest ne $checksum;

	}

}

# Else generate the MD5 digest to STDOUT

else

{

	foreach my $file (@files)

	{

		my $digest= &mkmd5($file);

		print "$digest  $file\n";

	}

}

#

# This routine generates the MD5 digest of a file

#

sub mkmd5

{

	my $file= shift;

	open (FILE, $file) or die "$file: $!";

	binmode(FILE);

	my $digest= Digest::MD5->new->addfile(*FILE)->hexdigest;

	close FILE;

	return $digest;

}

#

# Print the help text

#

sub usage

{

	print <<EOF;

$0 version $VER by Matt Wagner <matt\@mysql.com>

Usage:

$0 [-c [file]] |  [file1...]

Generates or checks MD5 message digests.

Options:

-c, --check	Check message digests (default is generate)

-h, --help	Display this text and exit

The input for -c should be the list of message digests and file names that is

printed on STDOUT by this program when it generates digests.

EOF

	exit(0);

}