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).

       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.  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.

4th Berkeley Distribution                        9 January 1993                                       RECOVER(6)