Create smolcat.c

smolcat.c

@@ -0,0 +1,43 @@
+#!/bin/tcc -run
+
+/**
+ * smol cat: unbuffered echo for terminal testing
+ * Ondřej Hruška, Aug 2017
+ * MIT license
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <termios.h>
+#include <signal.h>
+
+void signal_handler(int sig);
+
+struct termios old;
+
+int main(void)
+{
+  struct termios new;
+  char c;
+  signal(SIGTERM, signal_handler);
+  signal(SIGINT, signal_handler);
+
+  tcgetattr(TCSANOW, &old);
+  new = old;
+  new.c_lflag &= (~ECHO & ~ICANON);
+  tcsetattr(0, TCSANOW, &new);
+  tcsetattr(0, TCSANOW, &new);
+
+  // buffer swap with fallback reset after
+  fputs("\e[?1049h\ec\e[r", stdout);
+
+  while(1) putchar(getchar());
+}
+
+void signal_handler(int sig)
+{
+  // buffer unswap with fallback reset before
+  fputs("\ec\e[r\e[?1049l", stdout);
+  tcsetattr(0, TCSANOW, &old);
+  exit(0);
+}