prog.l_ada/TMP/Practice/04.10/shmat/svshm_string.h

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

static void
usage(const char *pname)
{
    fprintf(stderr, "Usage: %s [-cx] pathname proj-id num-sems\n",
            pname);
    fprintf(stderr, "    -c           Use IPC_CREAT flag\n");
    fprintf(stderr, "    -x           Use IPC_EXCL flag\n");
    exit(EXIT_FAILURE);
}

int main(int argc, char *argv[])
{
    int semid, nsems, flags, opt;
    key_t key;

    flags = 0;
    while ((opt = getopt(argc, argv, "cx")) != -1)
    {
        switch (opt)
        {
        case 'c':
            flags |= IPC_CREAT;
            break;
        case 'x':
            flags |= IPC_EXCL;
            break;
        default:
            usage(argv[0]);
        }
    }

    if (argc != optind + 3)
        usage(argv[0]);

    key = ftok(argv[optind], argv[optind + 1][0]);
    if (key == -1)
    {
        perror("ftok");
        exit(EXIT_FAILURE);
    }

    nsems = atoi(argv[optind + 2]);

    semid = semget(key, nsems, flags | 0600);
    if (semid == -1)
    {
        perror("semget");
        exit(EXIT_FAILURE);
    }

    printf("ID = %d\n", semid);

    exit(EXIT_SUCCESS);
}