To build, simply run:

> make

lfmerge takes two input files and searches for an overlap between the footer of
the first file and any region of the second. If an overlap is found, the merged
file is optionally written out. Only the footer of the first file need match -
data in the second file before the overlapping region will be replaced with the
contents of the first file before that region.

To detect where to look for candidate overlaps, the Rabin-Karp algorithm using
a rolling checksum is used. If a match is found, a comparison of the
overlapping region is performed and the extent of the match reported.