如何使用时间函数并通过命名管道传递时间

Question

I am trying to create client server communication through named pipe. From my client I want to send current time. I am trying to use time() function but the time won't appear on my server side terminal. I just see provided text. What am I doing wrong?

server

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>

int main() {

    char *pathname = "/tmp/myfifo";
    int make_fifo = mkfifo(pathname, 0666);
    
    char str[80];
    for(;;){
        int opn = open(pathname, O_RDONLY);
        read(opn, str, sizeof(str));
        close(opn);

    }

    return 0;
}

client

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <time.h>

int main() {

    char *pathname = "/tmp/myfifo";
    time_t current_time = time(0);
    char str[80];
    
    int fd = open(pathname, O_WRONLY);
    fgets(str, 80, stdin);  
    write(fd, str, sizeof(str));
    write(fd, (void*) current_time, sizeof(current_time));

    close(fd);
    return 0;
}

Answer 1

What am I doing wrong?

1. client: Not passing the address of current_time . ^*1

    // write(fd, (void*) current_time, sizeof(current_time)); write(fd, &current_time, sizeof(current_time)); // Add &

2. server: not reading the time.

3. Ignoring return values of read()/write() .

---

^*1 Avoid casting like (void*) current_time . Casting tends to hide errors.