14_01__shmGetZ

ZC: Unix网络编程第2版 第2卷 第14章

 

1、

#include <iostream>
using namespace std;

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/ipc.h>
#include <sys/shm.h>

#define SVSHM_MODE (SHM_R | SHM_W | SHM_R >> 3 | SHM_R >> 6)

int main(int argc, char** argv)
{
    cout << "*** shmget *** Z ***" << endl;

    int c, id, oflag;
    char *ptr;
    size_t length;

    oflag = SVSHM_MODE | IPC_CREAT;
    while (c = (getopt(argc, argv, "e")) != -1)
    {
        switch (c)
        {
        case 'e':
            oflag |= IPC_EXCL;
            break;
        }
    }

    if (optind != argc-2)
    {
        printf("usage : shmget [-e] <pathname> <length>\n");
        return 0;
    }
    length = atol(argv[optind+1]);
    id = shmget(ftok(argv[optind], 0), length, oflag);
    ptr = (char*)shmat(id, NULL, 0);
    exit(0);

    return 0;
}

 

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