add keypad

1 files changed, 35 insertions, 0 deletions

diff --git a/util.c b/util.c
index 95268b4..ab9afcc 100644
--- a/util.c
+++ b/util.c
@@ -45,6 +45,41 @@ int fd_can_read (int fd)
   return 0;
 }
 
+ssize_t read_with_timeout (int fd, void *_b, size_t len, unsigned timeout)
+{
+  struct timeval tv = {0};
+  unsigned char *b = _b;
+  fd_set rfds;
+  ssize_t red, ret = 0;
+
+  tv.tv_sec = timeout / 10;
+  tv.tv_usec = (timeout % 10) * 100000;
+
+  while (tv.tv_sec || tv.tv_usec) {
+    FD_ZERO (&rfds);
+    FD_SET (fd, &rfds);
+
+    if (select (fd + 1, &rfds, NULL, NULL, &tv) == 1) {
+
+      red = read (fd, &b[ret], 1);
+
+      if (red == 1)
+        ret++;
+
+      if (red <= 0) {
+        if (ret) return ret;
+
+        return red;
+      }
+
+      if (ret == len)  return ret;
+
+    }
+  }
+
+  return ret;
+}
+
 int fd_drain (int fd)
 {
   char c;