1.\"- 2.\" Copyright 2003-2005 Colin Percival 3.\" All rights reserved 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted providing that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 16.\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 18.\" DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 22.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 23.\" IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 24.\" POSSIBILITY OF SUCH DAMAGE. 25.\" 26.Dd May 18, 2003 27.Dt BSDIFF 1 28.Os 29.Sh NAME 30.Nm bsdiff 31.Nd "generate a patch between two binary files" 32.Sh SYNOPSIS 33.Nm 34.Ar oldfile newfile patchfile 35.Sh DESCRIPTION 36The 37.Nm 38utility 39compares 40.Ar oldfile 41to 42.Ar newfile 43and writes to 44.Ar patchfile 45a binary patch suitable for use by 46.Xr bspatch 1 . 47When 48.Ar oldfile 49and 50.Ar newfile 51are two versions of an executable program, the 52patches produced are on average a factor of five smaller 53than those produced by any other binary patch tool known 54to the author. 55.Pp 56The 57.Nm 58utility 59uses memory equal to 17 times the size of 60.Ar oldfile , 61and requires 62an absolute minimum working set size of 8 times the size of 63.Ar oldfile . 64.Sh SEE ALSO 65.Xr bspatch 1 66.Sh AUTHORS 67.An Colin Percival Aq Mt cperciva@FreeBSD.org 68.Sh BUGS 69The 70.Nm 71utility does not store the hashes of 72.Ar oldfile 73or 74.Ar newfile 75in 76.Ar patchfile . 77As a result, it is possible to apply a patch to the wrong file; this 78will usually produce garbage. 79It is recommended that users of 80.Nm 81store the hashes of 82.Ar oldfile 83and 84.Ar newfile 85and compare against them before and after applying 86.Ar patchfile . 87