add simple beep applet

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
diff --git a/miscutils/beep.c b/miscutils/beep.c
new file mode 100644
index 0000000..d5c3531
--- /dev/null
+++ b/miscutils/beep.c
@@ -0,0 +1,119 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * beep implementation for busybox
+ *
+ * Copyright (C) 2009 Bernhard Reutner-Fischer
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ *
+ */
+#include "libbb.h"
+
+#include <linux/kd.h>
+#ifndef CLOCK_TICK_RATE
+#define CLOCK_TICK_RATE 1193180
+#endif
+
+#define OPT_f (1<<0)
+#define OPT_l (1<<1)
+#define OPT_d (1<<2)
+#define OPT_r (1<<3)
+/* defaults */
+#define FREQ (4440)
+#define LENGTH (50)
+#define DELAY (0)
+#define REPETITIONS (1)
+
+#define GET_ARG do { if (!*++opt) opt = *++argv; if (opt == NULL) bb_show_usage();} while (0)
+#define NEW_BEEP() { \
+	freq = FREQ; \
+	length = LENGTH; \
+	delay = DELAY; \
+	rep = REPETITIONS; \
+	}
+
+int beep_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int beep_main(int argc UNUSED_PARAM, char **argv)
+{
+	int speaker = get_console_fd_or_die();
+	unsigned freq, length, delay, rep;
+	unsigned long ioctl_arg;
+	char *opt = NULL;
+	bool do_parse = true;
+
+	NEW_BEEP()
+	while (*argv && *++argv) {
+		opt = *argv;
+
+		while (*opt == '-')
+			++opt;
+		if (do_parse)
+			switch (*opt) {
+			case 'f':
+				GET_ARG;
+				freq = xatoul(opt);
+				continue;
+			case 'l':
+				GET_ARG;
+				length = xatoul(opt);
+				continue;
+			case 'd':
+				GET_ARG;
+				delay = xatoul(opt);
+				continue;
+			case 'r':
+				GET_ARG;
+				rep = xatoul(opt);
+				continue;
+			case 'n':
+				break;
+			default:
+				bb_show_usage();
+				break;
+			}
+ again:
+		while (rep) {
+//bb_info_msg("rep[%d] freq=%d, length=%d, delay=%d", rep, freq, length, delay);
+			ioctl_arg = (int)(CLOCK_TICK_RATE/freq);
+			xioctl(speaker, KIOCSOUND, (void*)ioctl_arg);
+			usleep(1000 * length);
+			ioctl(speaker, KIOCSOUND, 0);
+			if (rep--)
+				usleep(delay);
+		}
+		if (opt && *opt == 'n')
+				NEW_BEEP()
+		if (!do_parse && *argv == NULL)
+			goto out;
+	}
+	do_parse = false;
+	goto again;
+ out:
+	if (ENABLE_FEATURE_CLEAN_UP)
+		close(speaker);
+	return EXIT_SUCCESS;
+}
+/*
+ * so, e.g. Beethoven's 9th symphony "Ode an die Freude" would be
+ * something like:
+a=$((220*3))
+b=$((247*3))
+c=$((262*3))
+d=$((294*3))
+e=$((329*3))
+f=$((349*3))
+g=$((392*3))
+#./beep -f$d -l200 -r2 -n -f$e -l100 -d 10 -n -f$c -l400 -f$g -l200
+./beep -f$e -l200 -r2 \
+        -n -d 100 -f$f -l200 \
+        -n -f$g -l200 -r2 \
+        -n -f$f -l200 \
+        -n -f$e -l200 \
+        -n -f$d -l200  \
+        -n -f$c -l200 -r2  \
+        -n -f$d -l200  \
+        -n -f$e -l200  \
+        -n -f$e -l400  \
+        -n -f$d -l100 \
+        -n -f$d -l200 \
+*/