Allow fortune to use /dev/urandom if available to obtain its random

numbers.  If /dev/urandom is unavailable, it will fall back to
using the random() function.

I did this because I'm sick of seeing the same handful of fortunes
over and over, and I've seen the exact same fortune one too many times
when starting up two login shells at the same time.

2.2 safe.

1 files changed, 37 insertions, 6 deletions

diff --git a/games/fortune/fortune/fortune.c b/games/fortune/fortune/fortune.c
index e993a1be2bb4..5853bbf60cae 100644
--- a/games/fortune/fortune/fortune.c
+++ b/games/fortune/fortune/fortune.c
@@ -135,6 +135,7 @@ int	 form_file_list __P((char **, int));
 int	 fortlen __P((void));
 void	 get_fort __P((void));
 void	 get_pos __P((FILEDESC *));
+long 	 get_random __P((void));
 void	 get_tbl __P((FILEDESC *));
 void	 getargs __P((int, char *[]));
 void	 init_prob __P((void));
@@ -952,7 +953,7 @@ get_fort()
 	if (File_list->next == NULL || File_list->percent == NO_PROB)
 		fp = File_list;
 	else {
-		choice = random() % 100;
+		choice = get_random() % 100;
 		DPRINTF(1, (stderr, "choice = %d\n", choice));
 		for (fp = File_list; fp->percent != NO_PROB; fp = fp->next)
 			if (choice < fp->percent)
@@ -972,7 +973,7 @@ get_fort()
 	else {
 		if (fp->next != NULL) {
 			sum_noprobs(fp);
-			choice = random() % Noprob_tbl.str_numstr;
+			choice = get_random() % Noprob_tbl.str_numstr;
 			DPRINTF(1, (stderr, "choice = %d (of %ld) \n", choice,
 				    Noprob_tbl.str_numstr));
 			while (choice >= fp->tbl.str_numstr) {
@@ -1014,7 +1015,7 @@ FILEDESC	*parent;
 	register int		choice;
 
 	if (Equal_probs) {
-		choice = random() % parent->num_children;
+		choice = get_random() % parent->num_children;
 		DPRINTF(1, (stderr, "    choice = %d (of %d)\n",
 			    choice, parent->num_children));
 		for (fp = parent->child; choice--; fp = fp->next)
@@ -1024,7 +1025,7 @@ FILEDESC	*parent;
 	}
 	else {
 		get_tbl(parent);
-		choice = random() % parent->tbl.str_numstr;
+		choice = get_random() % parent->tbl.str_numstr;
 		DPRINTF(1, (stderr, "    choice = %d (of %ld)\n",
 			    choice, parent->tbl.str_numstr));
 		for (fp = parent->child; choice >= fp->tbl.str_numstr;
@@ -1113,13 +1114,13 @@ FILEDESC	*fp;
 #ifdef	OK_TO_WRITE_DISK
 		if ((fd = open(fp->posfile, 0)) < 0 ||
 		    read(fd, &fp->pos, sizeof fp->pos) != sizeof fp->pos)
-			fp->pos = random() % fp->tbl.str_numstr;
+			fp->pos = get_random() % fp->tbl.str_numstr;
 		else if (fp->pos >= fp->tbl.str_numstr)
 			fp->pos %= fp->tbl.str_numstr;
 		if (fd >= 0)
 			(void) close(fd);
 #else
-		fp->pos = random() % fp->tbl.str_numstr;
+		fp->pos = get_random() % fp->tbl.str_numstr;
 #endif /* OK_TO_WRITE_DISK */
 	}
 	if (++(fp->pos) >= fp->tbl.str_numstr)
@@ -1128,6 +1129,36 @@ FILEDESC	*fp;
 }
 
 /*
+ * get_random:
+ *	Get a random number, either via /dev/urandom, or random()
+ *	if /dev/urandom is not available.
+ */
+long
+get_random()
+{
+	static int	how = 0;
+	int	fd;
+	long	rnd;
+
+	if (how == 0) {
+		if ((fd = open("/dev/urandom", O_RDONLY)) >= 0)
+			how = 1;
+		else
+			how = 2;
+	}
+	if (how == 1) {
+		if (read(fd, (void *) &rnd, sizeof(rnd)) < 0) {
+			how = 2;
+		}
+		else {
+			rnd = abs(rnd);
+			return (rnd);
+		}
+	}
+	return (random());
+}
+
+/*
  * get_tbl:
  *	Get the tbl data file the datfile.
  */