From c70b9fe8823e8f21628725e634d5db1a6e3948d0 Mon Sep 17 00:00:00 2001
From: pfg <pfg@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Fri, 19 Sep 2014 18:24:02 +0000
Subject: [PATCH] awk: Use random(3) instead of rand(3)

While none of them is considered even near to cryptographic
level, random(3) is a better random generator than rand(3).

Use random(3) for awk as is done in other systems.

Thanks to Chenguang Li for discussing this in the lists
and submitting the patch upstream.

PR:		193147
MFC after:	5 weeks

git-svn-id: svn+ssh://svn.freebsd.org/base/head@271879 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 awk.1  | 2 +-
 main.c | 2 +-
 run.c  | 8 +++++---
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/awk.1 b/awk.1
index 057d128..9961910 100644
--- a/awk.1
+++ b/awk.1
@@ -209,7 +209,7 @@ or length of
 if no argument.
 .TP
 .B rand
-random number on (0,1).
+random number on [0,1).
 .TP
 .B srand
 sets seed for
diff --git a/main.c b/main.c
index 92043f4..08af8b5 100644
--- a/main.c
+++ b/main.c
@@ -78,7 +78,7 @@ int main(int argc, char *argv[])
 	/*signal(SIGSEGV, segvcatch); experiment */
 
 	srand_seed = 1;
-	srand(srand_seed);
+	srandom((unsigned long) srand_seed);
 
 	yyin = NULL;
 	symtab = makesymtab(NSYMTAB/NSYMTAB);
diff --git a/run.c b/run.c
index 9ffad50..7ac6c0b 100644
--- a/run.c
+++ b/run.c
@@ -1579,8 +1579,10 @@ Cell *bltin(Node **a, int n)	/* builtin functions. a[0] is type, a[1] is arg lis
 		}
 		break;
 	case FRAND:
-		/* in principle, rand() returns something in 0..RAND_MAX */
-		u = (Awkfloat) (rand() % RAND_MAX) / RAND_MAX;
+		/* random() returns numbers in [0..2^31-1]
+		 * in order to get a number in [0, 1), divide it by 2^31
+		 */
+		u = (Awkfloat) random() / (0x7fffffffL + 0x1UL);
 		break;
 	case FSRAND:
 		if (isrec(x))	/* no argument provided */
@@ -1588,7 +1590,7 @@ Cell *bltin(Node **a, int n)	/* builtin functions. a[0] is type, a[1] is arg lis
 		else
 			u = getfval(x);
 		tmp = u;
-		srand((unsigned int) u);
+		srandom((unsigned long) u);
 		u = srand_seed;
 		srand_seed = tmp;
 		break;