ash: factor out $RANDOM support

function                                             old     new   delta
next_random                                            -      46     +46
ash_main                                            1361    1356      -5
change_random                                        132      97     -35
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 46/-40)              Total: 6 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/shell/random.h b/shell/random.h
new file mode 100644
index 000000000..2d29a60e8
--- /dev/null
+++ b/shell/random.h
@@ -0,0 +1,19 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * $RANDOM support.
+ *
+ * Copyright (C) 2008 Denys Vlasenko
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+
+typedef struct random_t {
+        /* Random number generators */
+        int32_t galois_LFSR; /* Galois LFSR (fast but weak). signed! */
+        uint32_t LCG;        /* LCG (fast but weak) */
+} random_t;
+
+#define INIT_RANDOM_T(rnd, nonzero, v) \
+        ((rnd)->galois_LFSR = (nonzero), (rnd)->LCG = (v))
+
+uint32_t next_random(random_t *rnd) FAST_FUNC;