Today I learned about Scalar::Util::dualvar, and used it to my advantage.

hash.pl

#!/usr/bin/perl

use strict;
use warnings;

use Scalar::Util qw(dualvar);
use List::Util qw(first);
use constant {
  md5       => dualvar(length('62e2b06482fc7c4f4312797c81bf102a'),"md5"),
  sha1      => dualvar(length('59ad3fe46fa061bfd690e0bce261a4cb37a83e51'),"sha1"),
  sha256    => dualvar(length('d6d307d596a85d583f722b8a05005cf0df6739c9a7a037ca9339d3b21b0a21b5'),"sha256"),
  sha384    => dualvar(length('4273ae07d6db5576f1492fc340d0235b1a2cd2f048b21851bf3a807c515fc60be0e66d8c885c45580305146cf239497e'),"sha384"),
  sha512    => dualvar(length('c1396003c38aaed98d5d8586a0b7e56d1bfae4369f4befd852c2a6bae79d6a73cb308e4b49ea1df3fa8c38793bb88ae0446056fb13c4c71928346fbc699720b2'),"sha512"),
  ripemd160 => dualvar(length('9233d3756b9a0c23d720933133b5b92a16911a92'),"ripemd160"),
};

my @hashes = qw(d02d333c594f43280fdd8b728ba6129bc4bab4f0 884ed0bdce550e39f1026120cb0c57401199e32934205b953af8d01e442ddff1 mtfnpy);

foreach my $hash (@hashes) {
  my $hashtype = first { length($hash) == $_ } (sha1,sha256,sha384,sha512,md5,ripemd160);
  if ($hashtype) {
    printf "Hash %s is hash type %s, length %d\n",$hash,$hashtype,$hashtype;
  } else {
    printf "Hash %s is UNKNOWN, length %d\n",$hash,length($hash);
  }
}

Well fuck.

RIPEMD160(/etc/passwd)= 9233d3756b9a0c23d720933133b5b92a16911a92
     SHA1(/etc/passwd)= 59ad3fe46fa061bfd690e0bce261a4cb37a83e51