Termios

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

int main(void){
    static struct termios tc, newx;
    tcgetattr( STDIN_FILENO, &tc);
    newx = tc;

    newx.c_lflag &= ~(ICANON | ECHO);

    tcsetattr( STDIN_FILENO, TCSANOW, &newx);

    while(getchar() == 'a')
        printf("teste");

    tcsetattr( STDIN_FILENO, TCSANOW, &tc);

    return 0;
}