Thread: ICP shared memory

hi people i have been teaching myself C for the last few months and have recently moved onto ICP shared memory. I have with aid developed some simple code that prints out some chars i then wanted to do the same with int but cannont seem to get it to work.


producer

Code:

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>

#define SHMSZ     27

int main()
{
    int c;
    int shmid;
    key_t key;
    int *shm, *s;

    key = 5678;


    if ((shmid = shmget(key, SHMSZ, IPC_CREAT | 0666)) < 0) {
        perror("shmget");
        return(1);
    }


    if ((shm = shmat(shmid, NULL, 0)) == (int *) -1) {
        perror("shmat");
        return(1);
    }

    s = shm;

    for (c = 10; c <= 20; c++)
        *s++ = c;
    *s = -1;


    while (*shm != '*')
        sleep(1);

    return(0);
}

consumer

Code:

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdio.h>

#define SHMSZ     27

int main()
{
    int shmid;
    key_t key;
    char *shm, *s;


    key = 5678;


    if ((shmid = shmget(key, SHMSZ, 0666)) < 0) {
        perror("shmget");
        return(1);
    }


    if ((shm = shmat(shmid, NULL, 0)) == (char *) -1) {
        perror("shmat");
        return(1);
    }


    for (s = shm; *s != 0; s++)
        putchar(*s);
    putchar('\n');


    *shm = '*';

    return(0);
}

any ideas?