freebsd man page for bsdiff

BSDIFF(1)						    BSD General Commands Manual 						 BSDIFF(1)

NAME
     bsdiff -- generate a patch between two binary files

SYNOPSIS
     bsdiff oldfile newfile patchfile

DESCRIPTION
     The bsdiff utility compares oldfile to newfile and writes to patchfile a binary patch suitable for use by bspatch(1).  When oldfile and
     newfile are two versions of an executable program, the patches produced are on average a factor of five smaller than those produced by any
     other binary patch tool known to the author.

     The bsdiff utility uses memory equal to 17 times the size of oldfile, and requires an absolute minimum working set size of 8 times the size
     of oldfile.

SEE ALSO
     bspatch(1)

AUTHORS
     Colin Percival <cperciva@FreeBSD.org>

BUGS
     The bsdiff utility does not store the hashes of oldfile or newfile in patchfile.  As a result, it is possible to apply a patch to the wrong
     file; this will usually produce garbage.  It is recommended that users of bsdiff store the hashes of oldfile and newfile and compare against
     them before and after applying patchfile.

BSD
								   May 18, 2003 							       BSD