From 58bbb664811aa921f44fc9af01ec5b7a60294b42 Mon Sep 17 00:00:00 2001
From: Gregory Nutt <gnutt@nuttx.org>
Date: Thu, 19 Jul 2018 11:21:49 -0600
Subject: [PATCH] libs/libc/stdlib and include/stdlib.h:  Add implementation of
 random() and srandom().

---
 include/stdlib.h            | 10 +++++++---
 libs/libc/stdlib/lib_rand.c | 19 +++++++++++++++++--
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/include/stdlib.h b/include/stdlib.h
index 0229bed72f..f8cf9d7b24 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  * include/stdlib.h
  *
- *   Copyright (C) 2007-2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2016, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -45,6 +45,7 @@
 
 #include <sys/types.h>
 #include <stdint.h>
+#include <limits.h>
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -62,9 +63,9 @@
  * in sys/types.h.
  */
 
-/* Maximum value returned by rand() */
+/* Maximum value returned by rand().  Must be a minimum of 32767. */
 
-#define RAND_MAX 32767
+#define RAND_MAX INT_MAX
 
 /* Integer expression whose value is the maximum number of bytes in a
  * character specified by the current locale.
@@ -144,6 +145,9 @@ extern "C"
 void      srand(unsigned int seed);
 int       rand(void);
 
+#define   srandom(s) srand(s)
+long      random(void);
+
 #ifndef CONFIG_DISABLE_ENVIRON
 /* Environment variable support */
 
diff --git a/libs/libc/stdlib/lib_rand.c b/libs/libc/stdlib/lib_rand.c
index 1061d33923..529d664535 100644
--- a/libs/libc/stdlib/lib_rand.c
+++ b/libs/libc/stdlib/lib_rand.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * libs/libc/stdlib/lib_rand.c
  *
- *   Copyright (C) 2007, 2011, 2016 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2011, 2016, 2018 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -41,6 +41,7 @@
 
 #include <sys/types.h>
 #include <stdlib.h>
+#include <limits.h>
 
 #include <nuttx/lib/lib.h>
 
@@ -59,5 +60,19 @@
 
 int rand(void)
 {
-  return (int)nrand(32768L);
+  return (int)nrand(INT_MAX);
+}
+
+/****************************************************************************
+ * Name:  random
+ *
+ * Description:
+ *   Generate a non-negative, integer random number in the range of 0 through
+ *   (LONG_MAX - 1)
+ *
+ ****************************************************************************/
+
+long random(void)
+{
+  return (long)nrand(LONG_MAX);
 }