not 100% sure of what you are after, below, a trivial example to capture each char as entered plus catch a couple of signals .... if this is not what you are after (or could form the basis of ... ), please elaborate, also - share what you have tried - regardless of any shortcomings !

//
//use(d) https://www.man7.org/linux/man-pages/man3/termios.3.html as reference
//

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

struct termios currentSettings;

void resetSTDIN(struct termios *currentSettings) {
    tcsetattr(STDIN_FILENO, TCSAFLUSH, currentSettings);  // reset to original settings
}

void setSTDIN(struct termios *currentSettings) {
    struct termios updatedSettings;

    tcgetattr(STDIN_FILENO, currentSettings);  // get current settings

    updatedSettings = *currentSettings;        // use those as basis for new settings

    updatedSettings.c_lflag &= ~ICANON;   // unset 'normal' aka canonical mode, add '|ECHO' if you don't want to see input
    updatedSettings.c_cc[VTIME] = 0;      // VTIME Timeout in deciseconds for noncanonical read (TIME) 0 == no timeout
    updatedSettings.c_cc[VMIN] = 1;       // VMIN  Minimum number of characters for noncanonical read (MIN).

    tcsetattr(STDIN_FILENO, TCSAFLUSH, &updatedSettings);
}

void catchSignals(int sig) {
    resetSTDIN(&currentSettings);
    exit(1);
}

int main() {

    setSTDIN(&currentSettings);

    signal(SIGINT|SIGQUIT, catchSignals);  // trap ^C, ^\ amend as reqd

    printf("[q|Q|^C|^D]' to exit):\n");

    char c;
    const char ctrlD=4;
    while ( read(STDIN_FILENO, &c, 1) == 1 ) {
        if ( c == ctrlD || c == 'q' || c == 'Q' )
        break;

        //printf("%c", c); // if ECHO masked and you want to see the output ...
    }

    resetSTDIN(&currentSettings);
    return 0;
}