1.\" Copyright (c) 2008 The DragonFly Project. All rights reserved. 2.\" 3.\" This code is derived from software contributed to The DragonFly Project 4.\" by Matthew Dillon <dillon@backplane.com> 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in 14.\" the documentation and/or other materials provided with the 15.\" distribution. 16.\" 3. Neither the name of The DragonFly Project nor the names of its 17.\" contributors may be used to endorse or promote products derived 18.\" from this software without specific, prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 26.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" $DragonFly: src/usr.bin/undo/undo.1,v 1.5 2008/07/16 21:38:10 dillon Exp $ 34.Dd May 31, 2008 35.Dt UNDO 1 36.Os 37.Sh NAME 38.Nm undo 39.Nd Undo changes made to files on HAMMER filesystems 40.Sh SYNOPSIS 41.Nm 42.Op Fl adDiuv 43.Op Fl o Ar outfile 44.Op Fl t Ar transaction-id 45.Op Fl t Ar transaction-id 46.Ar 47.Sh DESCRIPTION 48The 49.Nm 50utility acquires an older version of the specified files and can output 51them to stdout, generate a file with the previous contents, or generate 52a diff to stdout. A history can also be generated. 53.Pp 54The options are as follows: 55.Bl -tag -width indent 56.It Fl d 57Generate a unified diff from the older version to the current version. 58.It Fl D 59Generate a unified diff from the current version to the older version. 60.It Fl i 61Generate a single line giving the transaction id and converted timestamp 62of the version of the file requested, rather than dumping the contents 63of the file. 64.It Fl a 65Iterate through the file's entire history generating undo files, diffs, 66output, etc. Note that due to the way file creation is laid down a 67file may appear to be zero-filled just after creation before the data 68is actually synced. There will be a later version with the synced 69data. This is a known bug. 70.It Fl u 71Output to a file with name synthesized from the input filename postfixed with ".undo". 72If not specified output is either to stdout or, if a single file argument 73is given, the file specified by the 74.Fl o 75option. 76.It Fl v 77Increase verboseness. 78.It Fl o Ar outfile 79Output to the specified file instead of to stdout. If iterating through 80a file's entire history 81.Ar outfile 82will be postfixed with an iteration number in the form "outfile.%04d". 83If multiple files are specified 84.Ar outfile 85is used as a template where '%s' is replaced with the last component of 86each file path. When used with multiple files '%%' must be used in the 87.Ar outfile 88specification to indicate a '%'. When used with a single file the 89.Ar outfile 90string is used verbatim. 91.It Fl t Ar transaction-id 92Specify how far to go back in time, by giving a HAMMER 93transaction id (0x16chars). If not specified 94the program will attempt to locate the most recent version of the 95file(s) prior to the current version. 96This option does not apply if 97.Fl a 98is specified. 99.Pp 100A second 101.Fl t 102specification may be given to provide two end-points for a diff, and 103will imply 104.Fl d 105unless overridden. 106.Pp 107Transaction ids always start with "0x". 108A simple index may be 109specified instead of a transaction id where 0 indicates the latest version 110and increasing values indicate older versions. 111.El 112.Sh EXAMPLES 113.Li "undo -d mytextfile" 114.Pp 115.Li "undo -o mytextfile.old mytextfile" 116.Sh DIAGNOSTICS 117Exit status is 0 on success and 1 on error. 118.Sh SEE ALSO 119.Xr hammer 8 120.Sh HISTORY 121The 122.Nm 123utility first appeared in 124.Dx 1.13 . 125.Sh AUTHORS 126.An Matthew Dillon Aq dillon@backplane.com 127.Sh BUGS 128HAMMER only synchronizes information to disk every 30 seconds or so and 129a quick file create / delete is done entirely in system memory and cannot 130be undone. This can be worked around by running 131.Dq Ar hammer synctid Op filesystem . 132