Add a controller shell.

This adds a mini shell to the tcp server that allows the user
to modify the current state.

Commands are in the form:

  set [int_attribute] (=|+=|-=) [number]
  set [bool_attribute] (on|off|toggle)
  print
  end

for example:

  set brightness += 5
  set power on
  print
  end

1 files changed, 43 insertions, 0 deletions

diff --git a/main/sockbuf.c b/main/sockbuf.c
new file mode 100644
index 0000000..0fede63
--- /dev/null
+++ b/main/sockbuf.c
@@ -0,0 +1,43 @@
+#include "sockbuf.h"
+
+#include <unistd.h>
+#include <string.h>
+
+void sockbuf_write(sockbuf_t* sockbuf, const char* value)
+{
+  write(sockbuf->socket, value, strlen(value));
+}
+
+sockbuf_t* init_sockbuf(sockbuf_t* sockbuf, int socket)
+{
+  memset(sockbuf, 0, sizeof(sockbuf_t));
+  sockbuf->socket = socket;
+
+  return sockbuf;
+}
+
+int peek_char(sockbuf_t* sockbuf)
+{
+  if (sockbuf->next == sockbuf->last) {
+    sockbuf->next = 0;
+    int size = read(sockbuf->socket, sockbuf->buf, sizeof(sockbuf->buf));
+    sockbuf->last = (uint8_t) size;
+
+    if (size <= 0) {
+      return size - 1;
+    }
+  }
+
+  return sockbuf->buf[sockbuf->next];
+}
+
+int get_char(sockbuf_t* sockbuf)
+{
+  int ret = peek_char(sockbuf);
+
+  if (ret >= 0) {
+    sockbuf->next ++;
+  }
+
+  return ret;
+}