共享内存

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include<unistd.h>
 4 #include<string.h>
 5 #include<sys/types.h>
 6 #include<sys/wait.h>
 7 
 8 #include<sys/ipc.h>
 9 #include<sys/shm.h>
10 
11 int main(int arg ,char *args[])
12 {
13     
14 /*    创建共享文件
15  * int shmid = shmget(IPC_PRIVATE,1024,0666);
16     if(shmid < 0)
17         printf("error
");
18     else
19         printf("success
");
20 */
21     
22     
23     
24 /*    进程挂载共享文件
25     char* shmbuf;
26     int shmid=0;
27     if(arg>1)
28     {
29         shmid = atoi(args[1]);//通过命令行传递共享内存IP号
30         shmbuf = shmat(shmid,0,0);//附加到共享内存
31         sleep(60);
32         shmdt(shmbuf);
33     }
34 */
35         char* shmbuf;
36         int shmid=0;
37         if(arg>2)
38         {
39             shmid = atoi(args[1]);//通过命令行传递共享内存IP号
40             shmbuf = shmat(shmid,0,0);//附加到共享内存
41             if(atoi(args[2])==1)  //write shared mem
42             {
43                 scanf("%s",shmbuf);
44             }
45             if(atoi(args[2])==2)//read shared mem
46             {
47                 printf("%s
",shmbuf);
48             }
49             shmdt(shmbuf);
50         }
51 
52     return 0;
53 }