String::CRC::Cksum is a Perl extension for calculating checksums in a manner compatible with the POSIX cksum program.
OO style: use String::CRC::Cksum;
$cksum = String::CRC::Cksum->new;
$cksum1 = $cksum->new; # clone (clone is reset)
$cksum->add("string3", "string4", "string5", ...);
($cksum, $size) = $cksum->peek;
($cksum, $size) = $cksum->result;
$cksum1->addfile(*file1); # note: adding many files
$cksum1->addfile(*file2); # is probably a silly thing
$cksum1->addfile(*file3); # to do, but you *could*...
Functional style: use String::CRC::Cksum qw(cksum);
$cksum = cksum("string1", "string2", ...);
($cksum, $size) = cksum("string1", "string2", ...);
$cksum = cksum(*FILE);
($cksum, $size) = cksum(*FILE);
The String::CRC::Cksum module calculates a 32 bit CRC, generating the same CRC value as the POSIX cksum program. If called in a list context, returns the length of the data object as well, which is useful for fully emulating the cksum program. The returned checksum will always be a non-negative integral number in the range 0..2^32-1.
Despite its name, this module is able to compute the checksum of files as well as of strings. Just pass in a reference to a filehandle, or a reference to any object that can respond to a read() call and eventually return 0 at "end of file".
Beware: consider proper use of binmode() if you are on a non-UNIX platform or processing files derived from other platforms.
The object oriented interface can be used to progressively add data into the checksum before yielding the result.
The functional interface is a convenient way to get a checksum of a single data item.
None of the routines make local copies of passed-in strings so you can safely Cksum large strings safe in the knowledge that there won't be any memory issues.
Passing in multiple files is acceptable, but perhaps of questionable value. However I don't want to hamper your creativity...