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Here is a short guide on patching your NetHack sources, assuming you have already managed to compile your copy.

On Windows

Please see the article on compiling, the following assumes you have installed MinGW and NetHack's sources to the locations shown in that article.

  • Unpack that into the bin directory of MinGW, so that the patch.exe will be in the same directory as mingw32-make.exe (e.g. c:\mingw\bin).
  • Find the diff-file you want to patch, and download it on to your computer, preferably in the NetHack sources root directory, c:\nh343.

Note that linux-style line endings will cause problems, you need to convert those into Windows-style ones! You can do this for example copypasting the contents of that file from a browser window into Notepad, and then saving the notepad file. In this example, we'll be using the menucolors-patch available at We'll assume the file is saved in c:\nh343\ as nh343-menucolor.diff

  • Start cmd.exe and do the following:
cd c:\nh343
patch -p1 < nh343-menucolor.diff

The 1 after the -p might need to be changed to 0 or possibly 2 for other patches.

note: On MS-Windows, the patchfile must be a text file, i.e. CR-LF must be used as line endings. A file with LF may give the error: "Assertion failed, hunk, file patch.c, line 343," unless the option '--binary' is given.

note: Newer version of windows require administrative privileges to run files named patch, which can break GNU patch, see here for a workaround:

  • Some patches require extra configuration steps before compiling. For menucolors, you need to edit c:\nh343\include\config.h by changing the line


/* # define MENU_COLOR_REGEX */

This changes the menucolors, so it won't try to use regular expressions, because MinGW does not come with regex header files. Menucolors also comes with it's own short README file, which should be c:\nh343\README.menucolor

  • Compile NetHack, by running install.bat (Assuming you created one when compiling the source) or manually.
  • Add the following to your NetHack configuration file, so the menucolors actually does something:
MENUCOLOR="* blessed *"=green
MENUCOLOR="* holy *"=green
MENUCOLOR="* cursed *"=red
MENUCOLOR="* unholy *"=red
  • Start NetHack. Now all blessed and holy items in your inventory should be shown in green, cursed and unholy in red.

Regexp on Windows

If you want to use regular expressions for menucolors:

  • Edit src\Makefile.gcc and add -lpcre to WINPLIBS. There's two definitions of WINPLIBS, one is for TTY, the other for graphical GUI.
  • Uncomment the MENU_COLOR, MENU_COLOR_REGEX and MENU_COLOR_REGEX_POSIX defines in include\config.h.
  • Unpack the PCRE development package and copy libpcre.dll.a to c:\mingw\lib\ and pcre.h, pcreposix.h and regex.h to c:\mingw\include\
  • Run install.bat to compile NetHack.
  • Unpack the PCRE binary package and copy pcre3.dll into the directory where NetHack binary is. (c:\nh343\binary\)
MENUCOLOR=" blessed "=green
MENUCOLOR=" holy "=green
MENUCOLOR=" cursed "=red
MENUCOLOR=" unholy "=red

Linux, and Unix in general

The typical way to patch is to stand in the root directory of the nethack source tree, apply the patch:

patch -pnum < my.patch

and then examine the warning or error messages, if any.

"-pnum" is used to strip path prefixes from the patch before trying to apply it. For example, if the patch contains lines on the form

--- slashem-0.0.7E7F1-orig/dat/Jedi.des 1970-01-01 01:00:00.000000000 +0100
+++ slashem-0.0.7E7F1/dat/Jedi.des      2005-07-20 14:55:01.434612456 +0200

you should strip off one level. You should strip off two levels if the patch says

--- a/slashem/dat/Jedi.des 1970-01-01 01:00:00.000000000 +0100
+++ b/slashem/dat/Jedi.des 2005-07-20 14:55:01.434612456 +0200