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

#include <stdlib.h>
#include <sys/wait.h>

int main(int argc, char** argv){
    int pipefds[2];
    int pipe_ret = pipe(pipefds);
    pid_t child_pid = fork();


    if (child_pid < 0) {
        perror("fork error");
        exit(1);
    } else if (child_pid == 0) {
        // child
        char* buf = "Hello parent\n";
        close(pipefds[0]);
        printf("Child sending: %s\n", buf);
        write(pipefds[1], buf, strlen(buf) + 1 /* \0 terminator */);

    } else {
        // parent
        char buf[1024];
        int child_exit_status;
        close(pipefds[1]);
        read(pipefds[0], buf, 1024);
        printf("Child sent:\n");
        puts(buf);
    
        waitpid(child_pid, &child_exit_status, 0);

    }
    return 0;

}