LRC - Perl interface for longitudinal redundancy check generation

The Longitudinal Redundancy Check (LRC) is a one byte character,
commonly used as a byte-field in data transmission over analog systems.

Most commonly, in STX-ETX bounded strings sent in financial protocols.
Following some previous experience with such protocols, I wrote 
an LRC function in perl and later decided to re-write in C
for efficiency.  The result is this module String::LRC,
which generates this aforementioned byte.

Commonly used in financial protocols as follows with ETX (ASCII 03)
appended to LRC sum and packets after the STX (ASCII 02), payload, 
and ETX chars. 

WWW: http://search.cpan.org/dist/String-LRC/