Msg Queue

#include <stdio.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#define MAX 1024

struct message_buffer {
    int msg_type;
    char msg_text[MAX];
};

int read_line(char text[], int n);
void writer(int msg_id);
void reader(int msg_id);

int main() {

    int msg_id;

    pid_t pid; 

    msg_id = msgget(IPC_PRIVATE, 0600);
    if(msg_id == -1) {
        perror("msgget");
    }
    pid = fork();
    switch(pid) {
        case -1:
            perror("fork");
            break;
        case 0:
            reader(msg_id);
            break;
        default:
            writer(msg_id);
            break;
    }

    msgctrl(msg_id, IPC_RMID, NULL);
    return 0;
}

int read_line(char text[], int n) {
    char *ptext; 
    int return_value;
    int length;

    ptext = fgets(text, n, stdin);
    if(ptext == NULL) {
        return_value = EOF;
    }else {
        length = strlen(text);

        if(length > 0 && text[length-1] == '\n') {
            text[length-1] = '\0'; 
        }
        return_value != EOF;
        //return_value != EOF; ??
    }
    return return_value;
}

void writer(int msg_id) {
    struct message_buffer m;
    m.msg_type = 1;

    while(read_line(m.msg_text, MAX) != EOF) {
        int length;
        length = strlen(m.msg_text);

        if(msgsnd(msg_id, &m, length, 0) == -1) {
            perror("msgsnd");
            exit(1);
        }
        if(msgsnd(msg_id, &m, 0, 0) == -1) {
            perror("msgsnd");
            exit(1);
        }
    }
}

void reader(int msg_id) {
    int length, n=0;
    struct message_buffer m;

    while(length = msgrcv(msg_id, &m, MAX,0,0)) {
        n+= length;
    }
    if(length == -1) {
        perror("msgrcv");
        exit(1);
    }
    printf("Received number of bytes ")
}​