1 .TH RECOVER 6 "14 December 2015" NETHACK
11 .ND $NHDT-Date: 1524689550 2018/04/25 20:52:30 $
12 .NB $NHDT-Branch: NetHack-3.6.0 $
13 .NR $NHDT-Revision: 1.9 $
16 recover \- recover a NetHack game interrupted by disaster
26 Occasionally, a NetHack game will be interrupted by disaster
27 when the game or the system crashes.
28 Prior to NetHack v3.1, these games were lost because various information
29 like the player's inventory was kept only in memory.
30 Now, all pertinent information can be written out to disk,
31 so such games can be recovered at the point of the last level change.
37 which files to process.
38 Each base option specifies recovery of a separate game.
42 option, which must be the first argument if it appears,
43 supplies a directory which is the NetHack playground.
44 It overrides the value from NETHACKDIR, HACKDIR, or the directory
45 specified by the game administrator during compilation
46 (usually /usr/games/lib/nethackdir).
49 For recovery to be possible,
51 must have been compiled with the INSURANCE option, and the run-time option
53 must also have been on.
56 For recovery to be possible,
58 must have been compiled with the INSURANCE option (this configuration was),
59 and the run-time option
61 must also have been on.
65 was created without support for recovery.
68 NetHack normally writes out files for levels as the player leaves them,
69 so they will be ready for return visits.
70 When checkpointing, NetHack also writes out the level entered and
71 the current game state on every level change.
72 This naturally slows level changes down somewhat.
74 The level file names are of the form base.nn, where nn is an internal
75 bookkeeping number for the level.
76 The file base.0 is used for game identity, locking, and, when checkpointing,
78 Various OSes use different strategies for constructing the base name.
79 Microcomputers use the character name, possibly truncated and modified
80 to be a legal filename on that system.
81 Multi-user systems use the (modified) character name prefixed
82 by a user number to avoid conflicts,
83 or "xlock" if the number of concurrent players is being limited.
84 It may be necessary to look in the playground to find the correct
85 base name of the interrupted game.
87 will transform these level files into a save file of the same name as
93 must be able to read and delete files from the playground
94 and create files in the save directory,
95 it has interesting interactions with game security.
96 Giving ordinary players access to
98 through setuid or setgid is tantamount to leaving the playground
100 with respect to both cheating and messing up other players.
101 For a single-user system, this of course does not change anything,
102 so some of the microcomputer ports install
106 For a multi-user system,
107 the game administrator may want to arrange for all .0 files in the
108 playground to be fed to recover when the host machine boots,
109 and handle game crashes individually.
110 If the user population is sufficiently trustworthy,
112 can be installed with the same permissions the
117 is easily compiled from the distribution utility directory.
124 will overwrite existing savefiles of the same name.
128 they may be compressed afterwards if desired,
129 but even a compression-using
131 will find them in the uncompressed form.
137 makes no attempt to find out if a base name specifies a game in progress.
138 If multiple machines share a playground, this would be impossible to
142 should be taught to use the nethack playground locking mechanism to
145 This file is Copyright (C) \*(Na and was last modified \*(Nd (version
147 NetHack may be freely redistributed. See license for details.