NAME

       recover - recover a NetHack game interrupted by disaster

SYNOPSIS

       recover [ -d directory ] base1 base2 ...

DESCRIPTION

       Occasionally,  a NetHack game will be interrupted by disaster when the game or the system crashes.  Prior
       to NetHack v3.1, these games were lost because various information like the player's inventory  was  kept
       only  in  memory.   Now,  all  pertinent  information  can  be  written out to disk, so such games can be
       recovered at the point of the last level change.

       The base options tell recover which files to process.  Each base option specifies recovery of a  separate
       game.

       The  -d option, which must be the first argument if it appears, supplies a directory which is the NetHack
       playground.  It overrides the value from NETHACKDIR, HACKDIR, or the  directory  specified  by  the  game
       administrator during compilation (usually /usr/games/lib/nethackdir).

       ^?ALLDOCS For recovery to be possible, nethack must have been compiled with the INSURANCE option, and the
       run-time  option  checkpoint must also have been on.  ^: ^?INSURANCE For recovery to be possible, nethack
       must have been compiled with the INSURANCE option (this  configuration  was),  and  the  run-time  option
       checkpoint  must  also  have  been  on.  ^: This configuration of nethack was created without support for
       recovery.  ^.  ^.  NetHack normally writes out files for levels as the player leaves them, so  they  will
       be  ready  for  return  visits.   When  checkpointing,  NetHack also writes out the level entered and the
       current game state on every level change.  This naturally slows level changes down somewhat.

       The level file names are of the form base.nn, where nn is an internal bookkeeping number for  the  level.
       The file base.0 is used for game identity, locking, and, when checkpointing, for the game state.  Various
       OSes  use  different  strategies  for constructing the base name.  Microcomputers use the character name,
       possibly truncated and modified to be a legal filename  on  that  system.   Multi-user  systems  use  the
       (modified)  character  name  prefixed  by  a  user number to avoid conflicts, or "xlock" if the number of
       concurrent players is being limited.  It may be necessary to look in the playground to find  the  correct
       base name of the interrupted game.  recover will transform these level files into a save file of the same
       name as nethack would have used.

       Since  recover  must  be  able  to read and delete files from the playground and create files in the save
       directory, it has interesting interactions with game security.  Giving ordinary players access to recover
       through setuid or setgid is tantamount to leaving the playground world-writable,  with  respect  to  both
       cheating  and  messing  up  other  players.   For  a  single-user  system, this of course does not change
       anything, so some of the microcomputer ports install recover by default.

       For a multi-user system, the game administrator may want to arrange for all .0 files in the playground to
       be fed to recover when the host machine boots,  and  handle  game  crashes  individually.   If  the  user
       population  is  sufficiently  trustworthy, recover can be installed with the same permissions the nethack
       executable has.  In either case, recover is easily compiled from the distribution utility directory.

NOTES

       Like nethack itself, recover will overwrite existing savefiles of the same name.   Savefiles  created  by
       recover  are  uncompressed;  they  may  be compressed afterwards if desired, but even a compression-using
       nethack will find them in the uncompressed form.

SEE ALSO

       nethack(6)

BUGS

       recover makes no attempt to find out if a base name specifies a game in progress.  If  multiple  machines
       share a playground, this would be impossible to determine.

       recover should be taught to use the nethack playground locking mechanism to avoid conflicts.

COPYRIGHT

       This  file  is Copyright (C) Kenneth Lorber and was last modified 2018/04/25 (version NetHack-3.6.0:1.9).
       NetHack may be freely redistributed.  See license for details.

NETHACK                                         14 December 2015                                      RECOVER(6)