program that starts two threads and waits for their completion

Question

My program contains two threads for which they are expected to end. I use a single variable that is shared between threads and this is x and a single mutex. The q key ends the thread

Problems I want to solve:

1. I want the stars (*) that are displayed one by one on the line now, I want them to be one after the other on the same line
2. I don't want to have to press enter after q to exit the program. I want it to exit the program immediately when I press q (no additional keys)

What should I change?

P.S (I have two warnings when running the program with gcc program.c -o program -lpthread, but that's not what I'm interested in at the moment, I'll solve it later)

program.c: In function ‘first’:
program.c:24:1: warning: control reaches end of non-void function [-Wreturn-type]
   24 | }
      | ^
program.c: In function ‘second’:
program.c:44:1: warning: control reaches end of non-void function [-Wreturn-type]
   44 | }
      | ^

code:

#include <stdio.h>
#include <pthread.h>
#include <stdlib.h>
#include <sys/time.h>

pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond_q = PTHREAD_COND_INITIALIZER;

char *x;

void *first(void *arg) {

        x = (char*)malloc(sizeof(char));
        do {
                scanf("%c", x);
                pthread_mutex_lock(&mut);
                if(x[0] == 'q') {
                        pthread_cond_signal(&cond_q);
                }
                pthread_mutex_unlock(&mut);
        } while( x[0] != 'q');
        free(x);
        printf("exited thread 1\n");
}

void *second(void *arg) {

        struct timespec ts;
        int ok = 1;

        pthread_mutex_lock(&mut);
        while(ok) {

                clock_gettime(CLOCK_REALTIME, &ts);
                ts.tv_sec += 1;

                ok = pthread_cond_timedwait(&cond_q, &mut, &ts);
                if(ok == 0) break;
                printf("*\n");

        }
        pthread_mutex_unlock(&mut);
        printf("exited thread 2\n");
}

int main()
{
        pthread_t read;
        pthread_t write;

        pthread_create(&read, NULL, &first,NULL);
        pthread_create(&write, NULL, &second,NULL);
        pthread_join(read, NULL);
        pthread_join(write, NULL);

        pthread_cond_destroy(&cond_q);
        pthread_mutex_destroy(&mut);

        return 0;
}