Grep - Revision history

Aximili: Add man page link

2020-03-20T04:16:43Z

Add man page link

209.151.235.14 at 18:34, 8 March 2015

2015-03-08T18:34:24Z

Jayt: Category:Development

2006-08-05T10:32:19Z

Category:Development

Kernigh: Use line number in link to eat.c, now eat.c#line486.

2006-07-09T03:57:05Z

Use line number in link to eat.c, now eat.c#line486.

62.240.71.4: fix typo, add info for finding function definitions in the src

2006-06-09T13:56:18Z

fix typo, add info for finding function definitions in the src

Kernigh: grep examples: grep SLASH'EM for Drow, NetHack for 'wrenching sensation', and learn why 'eating the little dog was a bad idea'.

2006-06-09T02:39:57Z

grep examples: grep SLASH'EM for Drow, NetHack for 'wrenching sensation', and learn why 'eating the little dog was a bad idea'.

New page

'''grep''' is a [[Unix]] command-line tool to search in files using regular expression.

In ''[[NetHack]]'', most of the useful source is in src/*.c and include/*.h, thus you can grep the sources like this:

$ '''cd ''/path/to/''nethack-3.4.3'''
$ '''grep -n ''regular-expression'' */*.{c,h}'''

Here is an example of searching for "Drow" in an unbuilt copy of the ''[[SLASH'EM]]'' sources:

$ '''cd ''/path/to/''slashem-0.0.7E7F2'''
$ '''grep -n Drow */*.{c,h}'''
src/u_init.c:1343: /* Drows can recognize all droven objects */
src/uhitm.c:40:/* Used to control whether Drow's sleep attack should succeed. */
include/you.h:356: /* KMH -- Drow is now its own role... */

It is sometimes useful to use grep to search for in-game messages. Want to know what a "wrenching sensation" is? Try this...

$ '''cd ''/path/to/''nethack-3.4.3'''
$ '''grep -n 'wrenching sensation' */*.{c,h}'''
src/sit.c:248: You_feel("a wrenching sensation.");
src/spell.c:116: You_feel("a wrenching sensation.");
src/teleport.c:847: You_feel("a wrenching sensation.");
src/teleport.c:869: You_feel("a wrenching sensation.");

It can sometimes be difficult to find something successfully with grep. For example, a grep on <code>'You feel a wrenching sensation'</code> fails because NetHack uses the <code>You_feel</code> function for those messages.

Soemtimes, the use of printf-style formatting also impedes your search. For example, suppose that [[you]] get the message ''"You feel that eating the little dog was a bad idea."''. You grep for it but get no results:

$ '''grep -n 'eating the little dog' */*.{c,h}'''
$

You suspect that the monster is variable. You try again, searching for "bad idea" somewhere in the same line after "eating":

$ '''grep -n 'eating.*bad idea' */*.{c,h}'''
src/eat.c:486: You_feel("that eating the %s was a bad idea.", mons[pm].mname);
$

A look in [[eat.c]] around line 486 (in [[vanilla]] 3.4.3) shows the following:

switch(pm) {
case PM_LITTLE_DOG:
case PM_DOG:
case PM_LARGE_DOG:
case PM_KITTEN:
case PM_HOUSECAT:
case PM_LARGE_CAT:
if (!CANNIBAL_ALLOWED()) {
You_feel("that eating the %s was a bad idea.", mons[pm].mname);
HAggravate_monster |= FROMOUTSIDE;
}
break;

From this, you guess that message means that you now have the [[intrinsic]] of [[aggravate monster]], and that eating a [[little dog]], [[dog]], [[large dog]], [[kitten]], [[housecat]], or [[large cat]] causes it.

[[Category:Articles]]

← Older revision		Revision as of 04:16, 20 March 2020
Line 1:		Line 1:
		+	{{man\|grep}}
	'''grep''' is a [[Unix]] command-line tool to search in files using regular expression.		'''grep''' is a [[Unix]] command-line tool to search in files using regular expression.

@@ Line 35: / Line 35: @@
   src/eat.c:486:              You_feel("that eating the %s was a bad idea.", mons[pm].mname);
+  $
 A look around [[eat.c#line486]] (in [[vanilla]] 3.4.3) shows the following:

← Older revision		Revision as of 10:32, 5 August 2006
Line 59:		Line 59:
	$		$

−	[[Category:~~Articles~~]]	+	[[Category:Development]]

@@ Line 36: / Line 36: @@
+  $
-A look in [[eat.c]] around line 486 (in [[vanilla]] 3.4.3) shows the following:
+A look around [[eat.c#line486]] (in [[vanilla]] 3.4.3) shows the following:
           switch(pm) {

@@ Line 25: / Line 25: @@
 It can sometimes be difficult to find something successfully with grep. For example, a grep on <code>'You feel a wrenching sensation'</code> fails because NetHack uses the <code>You_feel</code> function for those messages.
-Soemtimes, the use of printf-style formatting also impedes your search. For example, suppose that [[you]] get the message ''"You feel that eating the little dog was a bad idea."''. You grep for it but get no results:
+Sometimes, the use of printf-style formatting also impedes your search. For example, suppose that [[you]] get the message ''"You feel that eating the little dog was a bad idea."''. You grep for it but get no results:
   $ '''grep -n 'eating the little dog' */*.{c,h}'''
@@ Line 52: / Line 52: @@
 From this, you guess that message means that you now have the [[intrinsic]] of [[aggravate monster]], and that eating a [[little dog]], [[dog]], [[large dog]], [[kitten]], [[housecat]], or [[large cat]] causes it.
 [[Category:Articles]]