p11-11.c

SUN Solaris8平台下进程间通信

#include <stdio.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include "err_exit.h"
int main(void)
{
    key_t  key, msgflg;      /* 传递给msgget的key值和标志*/
    int  perm_flags, flags;  /* 读写许可权限和创建标志 */
    int  msqid;              /* msgget的返回值 */
    /* 输入key值 */
    printf("Enter the disired key in hex = ");
    scanf("%x",&key);
    /* 输入八进制读写许可权限 */
    printf("\nEnter the operation permiddipns in octal = ");
    scanf("%x",&perm_flags);
    /* 输入创建标志 */
    printf( "\nEnter corresponding number to set the disired flags:\n");
    printf( "No flags    = 0\n");
    printf( "IPC_CREAT   = 1\n");
    printf( "IPC_EXCL    = 2\n ");
    printf( "IPC_CREAT and IPC_EXCL = 3\n");
    printf( "Flags = ");
    scanf("%d",&flags);
    /* 检查输入值 */
    printf( "\nkey =0x%x, perm_flags = 0%o, flags = 0%o\n", 
            key, perm_flags, flags);
    /* 形成msgget的第二参数 */
    switch(flags){
    case 0:       /* 没有指定标志 */
        msgflg = (perm_flags | 0);
        break;
    case 1:       /* 要求设置IPC_CREAT标志 */
        msgflg = (perm_flags | 0);
        break;
    case 2:       /* 要求设置IPC_EXCL标志 */
        msgflg = (perm_flags | 0);
        break;
    case 3:       /* 要求设置IPC_EXCL和IPC_EXCL标志 */
        msgflg = (perm_flags | 0);
    }
    /* 调msgget打开消息队列 */
    printf( "\nmsgget: Calling msgget(%#lx, %#o)\n", key, msgflg);
    if ((msqid = msgget(key, msgflg)) == -1)
        err_exit("The msgget failed");
    else {
        printf( "The msgget succeeded: msqid = %d\n", msqid);
        exit(0);
    }
}