lab3

#include <semaphore.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <sys/mman.h>
#include <stdbool.h>

#define SEMAPHORE_NAME "/super_sem"

int main(int argc, char **argv) {
    int i, count = 0;
    sem_t *sem;
    int fd[2], nbytes;
    char readbuffer[80];
    char string[] = "";
    pid_t child_pid;
    pipe(fd);

    if ((sem = sem_open(SEMAPHORE_NAME, O_CREAT, 0777, 0)) == SEM_FAILED) {
        perror("sem_open");
        return 1;
    }
    if (fork() == 0) {
        while (true) {
            if (sem_wait(sem) < 0)
                perror("sem_wait");
            usleep(2000000);
            close(fd[1]);
            /* Read in a string from the pipe */
            nbytes = read(fd[0], readbuffer, sizeof(readbuffer));
            printf("Received string: %s \n", readbuffer);
            usleep(1000000);
            sem_post(sem);
        }
    } else {
        while (true) {
            scanf("%s", string);
            write(fd[1], string, (strlen(string) + 1));
            sem_post(sem);
        }
    }
}