1 files changed, 132 insertions, 0 deletions
diff --git a/usr.bin/notes/notes.c b/usr.bin/notes/notes.c
new file mode 100644
index 0000000..9db8b60
--- /dev/null
+++ b/usr.bin/notes/notes.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <ctype.h>
+
+#define BEEP_MSEC 100
+#define key_step(KEY) ('9' - ((KEY)))
+
+static uint8_t freq_addend = 0;
+
+static uint16_t freqtab[] = {
+    [ key_step('0') ] = 950,
+    [ key_step('9') ] = 900,
+    [ key_step('8') ] = 850,
+    [ key_step('7') ] = 800,
+    [ key_step('6') ] = 750,
+    [ key_step('5') ] = 700,
+    [ key_step('4') ] = 650,
+    [ key_step('3') ] = 600,
+    [ key_step('2') ] = 550,
+    [ key_step('1') ] = 500
+};
+
+static int beep_fd = 0;
+static bool running = false;
+
+static void
+beep(uint16_t freq)
+{
+    uint32_t payload;
+
+    if (beep_fd < 0) {
+        return;
+    }
+
+    payload = freq;
+    payload |= (BEEP_MSEC << 16);
+    write(beep_fd, &payload, sizeof(payload));
+}
+
+static inline void
+play_notekey(char key)
+{
+    uint8_t step = key_step(key);
+    uint16_t freq;
+
+    /* Should not happen */
+    if (step >= NELEM(freqtab)) {
+        step = key_step('0');
+    }
+
+    freq = freqtab[step] + freq_addend;
+    beep(freq);
+}
+
+static void
+play_loop(void)
+{
+    uint16_t freq = 0;
+    char c;
+
+    running = true;
+    while (running) {
+        c = getchar();
+        switch (c) {
+        case 'q':
+            running = false;
+            break;
+        case 'i':
+            /* NOTE: Overflow purposefully allowed here */
+            ++freq_addend;
+            printf("%d ", freq_addend);
+            break;
+        case 'd':
+            /* NOTE: Underflow purposefully allowed here */
+            --freq_addend;
+            printf("%d ", freq_addend);
+            break;
+        default:
+            if (!isdigit(c)) {
+                break;
+            }
+
+            play_notekey(c);
+        }
+    }
+
+    printf("\ncya!\n");
+}
+
+int
+main(int argc, char **argv)
+{
+    beep_fd = open("/dev/beep", O_WRONLY);
+    if (beep_fd < 0) {
+        return -1;
+    }
+
+    printf("bleep bloop time! - [i]nc/[d]ec\n");
+    play_loop();
+    close(beep_fd);
+}