=head1 NAME

String::CRC32 - Perl interface for cyclic redundency check generation

=head1 SYNOPSIS

    use String::CRC32;
    
    $crc = crc32("some string");
    $crc = crc32("some string", initvalue);

    $somestring = "some string";
    $crc = crc32($somestring);

    open(SOMEFILE, "location/of/some.file");
    binmode SOMEFILE;
    $crc = crc32(*SOMEFILE);
    close(SOMEFILE);

=head1 DESCRIPTION

The B<CRC32> module calculates CRC sums of 32 bit lenghts.
It generates the same CRC values as ZMODEM, PKZIP, PICCHECK and
many others.

Despite its name, this module is able to compute
the checksum of files as well as strings.

=head1 EXAMPLES

    $crc = crc32("some string");

  results in the same as

    $crc = crc32(" string", crc32("some"));

This is useful for subsequent CRC checking of substrings.

You may even check files:

    open(SOMEFILE, "location/of/some.file");
    binmode SOMEFILE;
    $crc = crc32(*SOMEFILE);
    close(SOMEFILE);

A init value may also been supplied in the above example.

=head1 AUTHOR

Soenke J. Peters <peters__perl@opcenter.de>

Please be so kind as to report any bugs/suggestions to the above address.

=head1 COPYRIGHT

CRC algorithm code taken from CRC-32 by Craig Bruce. 
The module stuff is inspired by a similar perl module called 
String::CRC by David Sharnoff & Matthew Dillon.
Horst Fickenscher told me that it could be useful to supply an init
value to the crc checking function and so I included this possibility.

The author of this package disclaims all copyrights and 
releases it into the public domain.