Stop stdin while command is running

Question

How to stop stdin while command is running in ash (not bash)?

For example:

1. sleep 10
2. type echo hello while sleep is still running
3. observe hello is in stdout after sleep finishes

Desired:

1. sleep 10
2. type echo hello while sleep is still running
3. observe shell as if nothing was typed in while sleep was running

I expect the solution would be something like: tput <stop stdin>; sleep 10; tput <restart stdin>; <enter>

This will not be in a shell script (only needs to work with interactive shell).

Answer 1

stty -echo disable the echo of your terminal, but if you type something, it will be memorized and the shell will get the typed key.

Then, before leaving, stty echo (revert back the echo mode), and drain the terminal input with this program :

#include <stdio.h>
#include <unistd.h>
#include <termios.h>

int main(void)
{
    tcflush(0, TCIFLUSH);
    return 0;
}

The whole thing would be stty raw -echo;sleep 10;stty sane;./my_program.

Using raw, avoid CtrlC CtrlZ to interfere. Sane imply echo and revert the terminal to a sane mode.