try to discover if there is input waiting on stdin

otherwise give the user a hint resolves #12
2015-01-12 16:24:47 +01:00
parent 98320c2c0d
commit b1a673b1f9
3 changed files with 38 additions and 0 deletions
@@ -57,6 +57,23 @@ FILE *open_file(const char *file_name, int mode) {
  return file;
 }

+bool input_ready(FILE *file) {
+  int fd = fileno(file);
+  fd_set rfds;
+  struct timeval tv;
+
+  FD_ZERO(&rfds);
+  FD_SET(fd, &rfds);
+
+  tv.tv_sec = 0;
+  tv.tv_usec = 0;
+
+  if(select(fd + 1, &rfds, NULL, NULL, &tv) == 1) {
+    return true;
+  }
+  return false;
+}
+
 unsigned char get_algorithm(EVP_PKEY *key) {
  int type = EVP_PKEY_type(key->type);
  switch(type) {