Re: arc4random for src/games
Looks good but I think this idiom used in hangman: pos = (double) random() / (RAND_MAX + 1.0) * (double) Dict_size; Can be replaced with: pos = arc4random_uniform(Dict_size); so long as Dict_size = UINT32_MAX, which should always be the case. A similar idiom is used by monop (compare to mille/roll.c). - todd
Re: arc4random for src/games
Todd C. Miller:
Looks good but I think this idiom used in hangman:
pos = (double) random() / (RAND_MAX + 1.0) * (double) Dict_size;
Can be replaced with:
pos = arc4random_uniform(Dict_size);
so long as Dict_size = UINT32_MAX, which should always be the case.
Hmm. Dict_size and ksymsize are off_t, although they are indeed
unlikely to grow to UINT32_MAX in practice.
A similar idiom is used by monop (compare to mille/roll.c).
Right.
Updated diff:
Index: arithmetic/arithmetic.c
===
RCS file: /cvs/src/games/arithmetic/arithmetic.c,v
retrieving revision 1.17
diff -u -p -r1.17 arithmetic.c
--- arithmetic/arithmetic.c 27 Oct 2009 23:59:23 - 1.17
+++ arithmetic/arithmetic.c 28 Aug 2013 14:30:16 -
@@ -124,9 +124,6 @@ main(int argc, char *argv[])
if (argc -= optind)
usage();
- /* Seed the random-number generator. */
- srandomdev();
-
(void)signal(SIGINT, intr);
/* Now ask the questions. */
@@ -177,7 +174,7 @@ problem(void)
int left, op, right, result;
char line[80];
- op = keys[random() % nkeys];
+ op = keys[arc4random_uniform(nkeys)];
if (op != '/')
right = getrandom(rangemax + 1, op, 1);
retry:
@@ -198,7 +195,7 @@ retry:
case '/':
right = getrandom(rangemax, op, 1) + 1;
result = getrandom(rangemax + 1, op, 0);
- left = right * result + random() % right;
+ left = right * result + arc4random_uniform(right);
break;
}
@@ -308,7 +305,7 @@ getrandom(int maxval, int op, int operan
struct penalty **pp, *p;
op = opnum(op);
- value = random() % (maxval + penalty[op][operand]);
+ value = arc4random_uniform(maxval + penalty[op][operand]);
/*
* 0 to maxval - 1 is a number to be used directly; bigger values
Index: backgammon/backgammon/main.c
===
RCS file: /cvs/src/games/backgammon/backgammon/main.c,v
retrieving revision 1.16
diff -u -p -r1.16 main.c
--- backgammon/backgammon/main.c27 Oct 2009 23:59:23 - 1.16
+++ backgammon/backgammon/main.c28 Aug 2013 14:34:54 -
@@ -100,7 +100,6 @@ main (argc,argv)
/* use whole screen for text */
begscr = 0;
- srandomdev(); /* seed random number generator */
getarg(argc, argv);
args[acnt] = '\0';
Index: backgammon/common_source/back.h
===
RCS file: /cvs/src/games/backgammon/common_source/back.h,v
retrieving revision 1.11
diff -u -p -r1.11 back.h
--- backgammon/common_source/back.h 14 Dec 2006 10:14:05 - 1.11
+++ backgammon/common_source/back.h 28 Aug 2013 14:35:11 -
@@ -43,7 +43,7 @@
#include term.h
#include unistd.h
-#define rnum(r)(random()%r)
+#define rnum(r)arc4random_uniform(r)
#define D0 dice[0]
#define D1 dice[1]
#define swap {D0 ^= D1; D1 ^= D0; D0 ^= D1; d0 = 1-d0;}
Index: battlestar/extern.h
===
RCS file: /cvs/src/games/battlestar/extern.h,v
retrieving revision 1.14
diff -u -p -r1.14 extern.h
--- battlestar/extern.h 5 Apr 2013 01:28:27 - 1.14
+++ battlestar/extern.h 28 Aug 2013 14:36:46 -
@@ -49,7 +49,7 @@
#define BITS (8 * sizeof (int))
#define OUTSIDE(position 68 position 246 position !=
218)
-#define rnd(x) (random() % (x))
+#define rnd(x) arc4random_uniform(x)
#define max(a,b) ((a) (b) ? (b) : (a))
/* avoid name collision with sys/param.h */
#define TestBit(array, index) (array[index/BITS] (1 (index % BITS)))
Index: battlestar/init.c
===
RCS file: /cvs/src/games/battlestar/init.c,v
retrieving revision 1.13
diff -u -p -r1.13 init.c
--- battlestar/init.c 27 Oct 2009 23:59:24 - 1.13
+++ battlestar/init.c 28 Aug 2013 14:37:03 -
@@ -46,7 +46,6 @@ initialize(const char *filename)
puts(First Adventure game written by His Lordship, the honorable);
puts(Admiral D.W. Riggle\n);
location = dayfile;
- srandomdev();
username = getutmp();
if (username == NULL)
errx(1, Don't know who you are.);
Index: bs/bs.c
===
RCS file: /cvs/src/games/bs/bs.c,v
retrieving revision 1.23
diff -u -p -r1.23 bs.c
--- bs/bs.c 14 Nov 2009 02:20:43 - 1.23
+++ bs/bs.c 28 Aug 2013 14:39:39 -
@@ -39,8 +39,6 @@
* v2.2 with bugfixes and strategical improvements, March 1998.
*/
-/* #define _POSIX_SOURCE */ /* ( random() ) */
-
#include sys/param.h
#include sys/types.h
#include curses.h
@@ -235,8 +233,6 @@ static void intro(void)
{
arc4random for src/games
This replaces srandomdev()+random() with calls to arc4random*() in
src/games. There isn't much practical benefit to this. Consider
it a style fix.
I have NOT touched the games that call srandom() with a particular seed
for deterministic gameplay.
Index: arithmetic/arithmetic.c
===
RCS file: /cvs/src/games/arithmetic/arithmetic.c,v
retrieving revision 1.17
diff -u -p -r1.17 arithmetic.c
--- arithmetic/arithmetic.c 27 Oct 2009 23:59:23 - 1.17
+++ arithmetic/arithmetic.c 28 Aug 2013 14:30:16 -
@@ -124,9 +124,6 @@ main(int argc, char *argv[])
if (argc -= optind)
usage();
- /* Seed the random-number generator. */
- srandomdev();
-
(void)signal(SIGINT, intr);
/* Now ask the questions. */
@@ -177,7 +174,7 @@ problem(void)
int left, op, right, result;
char line[80];
- op = keys[random() % nkeys];
+ op = keys[arc4random_uniform(nkeys)];
if (op != '/')
right = getrandom(rangemax + 1, op, 1);
retry:
@@ -198,7 +195,7 @@ retry:
case '/':
right = getrandom(rangemax, op, 1) + 1;
result = getrandom(rangemax + 1, op, 0);
- left = right * result + random() % right;
+ left = right * result + arc4random_uniform(right);
break;
}
@@ -308,7 +305,7 @@ getrandom(int maxval, int op, int operan
struct penalty **pp, *p;
op = opnum(op);
- value = random() % (maxval + penalty[op][operand]);
+ value = arc4random_uniform(maxval + penalty[op][operand]);
/*
* 0 to maxval - 1 is a number to be used directly; bigger values
Index: backgammon/backgammon/main.c
===
RCS file: /cvs/src/games/backgammon/backgammon/main.c,v
retrieving revision 1.16
diff -u -p -r1.16 main.c
--- backgammon/backgammon/main.c27 Oct 2009 23:59:23 - 1.16
+++ backgammon/backgammon/main.c28 Aug 2013 14:34:54 -
@@ -100,7 +100,6 @@ main (argc,argv)
/* use whole screen for text */
begscr = 0;
- srandomdev(); /* seed random number generator */
getarg(argc, argv);
args[acnt] = '\0';
Index: backgammon/common_source/back.h
===
RCS file: /cvs/src/games/backgammon/common_source/back.h,v
retrieving revision 1.11
diff -u -p -r1.11 back.h
--- backgammon/common_source/back.h 14 Dec 2006 10:14:05 - 1.11
+++ backgammon/common_source/back.h 28 Aug 2013 14:35:11 -
@@ -43,7 +43,7 @@
#include term.h
#include unistd.h
-#define rnum(r)(random()%r)
+#define rnum(r)arc4random_uniform(r)
#define D0 dice[0]
#define D1 dice[1]
#define swap {D0 ^= D1; D1 ^= D0; D0 ^= D1; d0 = 1-d0;}
Index: battlestar/extern.h
===
RCS file: /cvs/src/games/battlestar/extern.h,v
retrieving revision 1.14
diff -u -p -r1.14 extern.h
--- battlestar/extern.h 5 Apr 2013 01:28:27 - 1.14
+++ battlestar/extern.h 28 Aug 2013 14:36:46 -
@@ -49,7 +49,7 @@
#define BITS (8 * sizeof (int))
#define OUTSIDE(position 68 position 246 position !=
218)
-#define rnd(x) (random() % (x))
+#define rnd(x) arc4random_uniform(x)
#define max(a,b) ((a) (b) ? (b) : (a))
/* avoid name collision with sys/param.h */
#define TestBit(array, index) (array[index/BITS] (1 (index % BITS)))
Index: battlestar/init.c
===
RCS file: /cvs/src/games/battlestar/init.c,v
retrieving revision 1.13
diff -u -p -r1.13 init.c
--- battlestar/init.c 27 Oct 2009 23:59:24 - 1.13
+++ battlestar/init.c 28 Aug 2013 14:37:03 -
@@ -46,7 +46,6 @@ initialize(const char *filename)
puts(First Adventure game written by His Lordship, the honorable);
puts(Admiral D.W. Riggle\n);
location = dayfile;
- srandomdev();
username = getutmp();
if (username == NULL)
errx(1, Don't know who you are.);
Index: bs/bs.c
===
RCS file: /cvs/src/games/bs/bs.c,v
retrieving revision 1.23
diff -u -p -r1.23 bs.c
--- bs/bs.c 14 Nov 2009 02:20:43 - 1.23
+++ bs/bs.c 28 Aug 2013 14:39:39 -
@@ -39,8 +39,6 @@
* v2.2 with bugfixes and strategical improvements, March 1998.
*/
-/* #define _POSIX_SOURCE */ /* ( random() ) */
-
#include sys/param.h
#include sys/types.h
#include curses.h
@@ -235,8 +233,6 @@ static void intro(void)
{
char *tmpname;
-srandomdev(); /* Kick the random number generator */
-
(void) signal(SIGINT,uninitgame);
(void) signal(SIGINT,uninitgame);
if(signal(SIGQUIT,SIG_IGN) != SIG_IGN)
@@ -344,7 +340,7
