Perl 建立MD5

 讀文檔： http://search.cpan.org/~gaas/Digest-MD5-2.39/MD5.pm後，

 

非常有用章段：

This is useful when calculating checksum for files:

    use Digest::MD5;    my $file = shift || "/etc/passwd";    open(FILE, $file) or die "Can't open '$file': $!";    binmode(FILE);    $md5 = Digest::MD5->new;    while (<FILE>) {        $md5->add($_);    }    close(FILE);    print $md5->b64digest, " $file/n";

Or we can use the addfile method for more efficient reading of the file:

    use Digest::MD5;    my $file = shift || "/etc/passwd";    open(FILE, $file) or die "Can't open '$file': $!";    binmode(FILE);    print Digest::MD5->new->addfile(*FILE)->hexdigest, " $file/n";