notnotdnethack/Porting

  NetHack Porting Guidelines		v 3.4			1999-11-29


     1.0	Introduction

	This document goes through the steps required to port NetHack to a
new machine.  The basic steps in porting the program are:

	1.  Get the code onto your machine.  The parts of the current
	    directory setup you definitely need include src (NetHack code
	    shared by all systems), include (include files), util (code
	    for utility programs), and dat (various data files).  The
	    documentation in doc is strongly recommended.  You already
	    have the files in the top directory since you're reading this
	    one. :-)

	    A full list of the distribution files and their associated
	    OSes may be found in the top-level file "Files".

	    If your machine uses an OS already supported, you need the sys
	    subdirectory for that OS and possibly sys/share.  Otherwise,
	    get the closest match (say sys/msdos for single-tasking OSes
	    and sys/unix for multi-user OSes, along with sys/share, if
	    nothing else comes to mind).  You may want others for
	    comparison.

	    If your machine uses a windowing system already supported,
	    you need the win subdirectory for that system (or the
	    appropriate sys subdirectory if the windowing system was
	    previously considered restricted to one OS).

	2.  Modify the appropriate include files to customize NetHack to
	    your system.  You may need to add a new OS-specific "*conf.h"
	    file (see unixconf.h, pcconf.h, tosconf.h, etc. as examples).

	3.  If your machine uses a new OS instead of a variant of existing
	    OSes, add a new sys subdirectory.  Add, if required, a OS-
	    specific copy of "main.c", "tty.c" and "unix.c".  Possibly
	    add an OS-specific library (see "msdos.c" and "tos.c" as
	    examples) to provide functions NetHack wants and your OS lacks.

	4.  If your machine uses a new windowing system, follow doc/window.doc
	    carefully.  Put files implementing these routines in a win or
	    sys subdirectory as appropriate.

	5.  If your compilation environment isn't close to one already
	    supported, try starting from the UNIX makefiles.  Modify the
	    top level makefile and the src makefile as required.  Then run
	    an initial compile.  You are bound to get some errors.  You
	    should be able to fix them in a fairly simple fashion.  If
	    things seem to be getting too complex, take a step back, and
	    possibly send us some mail.  We might be able to help.

	6.  Mail all of your fixes to us in a contextual form so that we can
	    easily integrate them into the code.

	One general rule of thumb exists.  Always add code.  Don't delete
somebody else's code for yours -- it won't work on their machine if you do.
Always add your OS specific code inside #ifdef / #else / #endif constructs
so that it will be able to be folded back into the original code easily.


     2.0	Include Files

     2.1	config.h

	The file "config.h" is a master configuration file that determines
the basic features of the game, as well as many of the security options.
It is intended that end users configure the game by editing "config.h" and
an appropriate "*conf.h" file, so any #defines for individual preferences
should be added to those files.  OS-specific #defines that are not intended
to be changed should also go in "*conf.h"; try to find the most appropriate
place for other #defines.

	The following sections may require modification:

     -	Section 1:	OS and window system selection.
			You may have to put a #define for your OS here.
			If your OS is yet another UNIX variant, put the
			#define in unixconf.h instead.
			An unfortunately large amount of stuff shares
			this section because the #definitions have to
			be seen before *conf.h is reached.  Don't add
			to this unless necessary.

     -	Section 2:	Global parameters and filenames.
			These will have to be customized to your system.

     -	Section 3:	Type definitions and other compiler behavior.
			These will have to be matched to your compiler.

     2.2	global.h

	This file defines things specific to NetHack that should not
require modification by an end user.  For a new port, you may have to add
automatic inclusion of another auxiliary config file (*conf.h) which you
wrote for your system.

     2.3	extern.h

	If you create any new source modules or new functions in old modules,
you must enter the names of the new external references (the functions defined
there for external use) in this file.

     2.4	system.h

	This file contains references for all hooks into the OS (via the
standard "C" libraries).  Depending on what your standard library looks like,
you may have to put new entries into this file.


     3.0	Source files

	The first step in getting the game up is to get the "makedefs"
program running.  This program is used to create configuration-specific
files for the game.

	Once "makedefs" has been built, the rest of the game can be compiled.
You may have to create an OS-specific module to handle things you want to
use, like a mouse or a ram-disk.

	The utility compilers "dgn_comp" and "lev_comp" may be a better
place to start.  They also require "makedefs" but are independent of
"nethack".  They are usually the last programs made, but since they are
much smaller they may be more tractable when first arguing with the include
files.  These programs create binary data files that "nethack" uses to
guide its dungeon creation.

     3.1	Makefiles

	This distribution provides makefiles for several kinds of systems.
There are joint makefiles for the various varieties of UNIX, makefiles for
MSDOS, a makefile for NT, and so on.  You may have to create a new
makefile for your specific machine.  You may even have to translate some
makefiles into a form more congenial to your system.  If possible, however,
add to one of those provided.

     3.2	termcap.c

	If your system wants to use tty windowing and it doesn't run off
of a termcap or terminfo database, you may have to put the appropriate
terminal control strings into termcap.c.  This has already been done for
MSDOS, and these mods can be used as an example.  You can also consider
using the termcap code from sys/share/tclib.c or sys/share/termcap.uu,
especially if your system supports multiple kinds of terminals.

     3.3	main.c

	You may need to create a new "main.c" module.  If you do, call it
[OS]main.c where the [OS] is replaced with the name of the OS you are porting
to.  This file contains the mainline module, which reads options from the
command line (or wherever) and processes them.  It also contains various
functions associated with game startup.

     3.4	tty.c

	You may need to create a new "tty.c" module.  If you do, call it
[OS]tty.c where the [OS] is replaced with the name of the OS you are porting
to.  This file contains the routines that configure the terminal/console
for raw I/O, etc.

     3.5	unix.c

	You may need to create a new "unix.c" module.  If you do, call it
[OS]unix.c where the [OS] is replaced with the name of the OS you are porting
to.  This file contains some OS dependencies concerning time and filename
creation.


	An object of the NetHack development project is to get the game
working on as many different types of hardware and under as many different
operating systems as is practical.  Any assistance will be appreciated.