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. Execute the generation operation for each version. 67.It Fl u 68Output to a file with name synthesized from the input filename postfixed with ".undo". 69If not specified output is either to stdout or, if a single file argument 70is given, the file specified by the 71.Fl o 72option. 73.It Fl v 74Increase verboseness. 75.It Fl o Ar outfile 76Output to the specified file instead of to stdout. If iterating through 77a file's entire history 78.Ar outfile 79will be postfixed with an iteration number in the form "outfile.%04d". 80If multiple files are specified 81.Ar outfile 82is used as a template where '%s' is replaced with the last component of 83each file path. When used with multiple files '%%' must be used in the 84.Ar outfile 85specification to indicate a '%'. When used with a single file the 86.Ar outfile 87string is used verbatim. 88.It Fl t Ar transaction-id 89Specify how far to go back in time, by giving a HAMMER 90transaction id (0x16chars). If not specified 91the program will attempt to locate the most recent version of the 92file(s) prior to the current version. 93This option does not apply if 94.Fl a 95is specified. 96.Pp 97A second 98.Fl t 99specification may be given when the 100.Fl d 101or 102.Fl D 103option is used, to provide two end-points for the diff. The file as-of 104the second 105.Fl t 106is used instead of the current version of the file. 107.El 108.Sh EXAMPLES 109.Li "undo -d mytextfile" 110.Pp 111.Li "undo -o mytextfile.old mytextfile" 112.Sh DIAGNOSTICS 113Exit status is 0 on success and 1 on error. 114.Sh SEE ALSO 115.Xr hammer 8 116.Sh HISTORY 117The 118.Nm 119utility first appeared in 120.Dx 1.13 . 121.Sh AUTHORS 122.An Matthew Dillon Aq dillon@backplane.com 123.Sh BUGS 124HAMMER only synchronizes information to disk every 30 seconds or so and 125a quick file create / delete is done entirely in system memory and cannot 126be undone. This can be worked around by running 127.Dq Ar hammer synctid Op filesystem . 128