Created student weenix repository

1 files changed, 22 insertions, 0 deletions

diff --git a/user/lib/libc/rand.c b/user/lib/libc/rand.c
new file mode 100644
index 0000000..711ae8e
--- /dev/null
+++ b/user/lib/libc/rand.c
@@ -0,0 +1,22 @@
+#include <stdlib.h>
+
+/* Random int between lo and hi inclusive */
+
+/* TODO Fix the rand/srand implementation to use the implementation in the
+ * (unused) macro which actually has decent pseudo-randomness properties. (No,
+ * you can't just change the mod base and expect it to still work fine...) */
+
+#define RANDOM(lo, hi)                                                        \
+    ((lo) +                                                                   \
+     (((hi) - (lo) + 1) * (randseed = (randseed * 4096 + 150889) % 714025)) / \
+         714025)
+
+static unsigned long long randseed = 123456L;
+
+int rand(void)
+{
+    randseed = (randseed * 4096 + 150889) % RAND_MAX;
+    return randseed;
+}
+
+void srand(unsigned int seed) { randseed = seed; }