Question

My app reading escape sequences from terminal in raw mode. And when it’s running on xterm I got F2 like “\eOQ”. But when it’s running in linux tty terminal (Switching by Ctrl-Alt-F1) I got “\e[[[B”.
What is the correct way to determine that I got F2 independent from terminal type application running on?

Answer 1

If you’re wanting to read terminal keypresses, you likely want to look at something like libtermkey , which abstracts the general problem away for you. Internally it uses a combination of terminfo lookups, or hardcoded knowledge of the extended xterm-like model for modified keypresses, so it can understand things like Ctrl-Up, which a regular curses/etc… cannot.

while((ret = termkey_waitkey(tk, &key)) != TERMKEY_RES_EOF) {
  termkey_strfkey(tk, buffer, sizeof buffer, &key, TERMKEY_FORMAT_VIM);
  printf("You pressed key %s\n", buffer);

  if(key.type == TERMKEY_TYPE_FUNCTION &&
     !key.modifiers &&
     key.code.number = 2)
    printf("Got F2\n");
}