Major update

- Add an IO system to hijack a bit of the terminal.
- Other minor fixes.

include/internal/generic.h

@@ -7,4 +7,20 @@ enum struct Direction : uint8_t {
   Forward,
   Backward
 };
+
+inline static bool write_all(int fd, const void *data, size_t len) {
+  const char *p = (const char *)data;
+  while (len > 0) {
+    ssize_t n = write(fd, p, len);
+    if (n > 0) {
+      p += n;
+      len -= (size_t)n;
+      continue;
+    }
+    if (n == -1 && errno == EINTR)
+      continue;
+    return false;
+  }
+  return true;
 }
+} // namespace bed::internal