IPC---共享内存的使用

  1 #include<stdio.h>
  2 #include<stdlib.h>
  3 #include<sys/mman.h>
  4 #include<unistd.h>
  5 #include<fcntl.h>
  6 #include<string.h>
  7 
  8 int main()
  9 {
 10         int fd = open("mytest.txt",O_RDWR | O_CREAT,0644);
 11         if(fd == -1 )
 12         {
 13                 perror("open error");
 14                 exit(1);
 15         }
 16 
 17         int len = ftruncate(fd,4);
 18         if(len == -1)
 19         {
 20                 perror("ftruncate error");
 21                 exit(1);
 22         }
 23         char * p=NULL;
 24         p = mmap(NULL,4,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);
 25         if( p == MAP_FAILED )
 26         {
 27                 perror("mmap error");
 28                 exit(1);
 29         }
 30         strcpy(p,"abvc\n");
 31 
 32         int ret = munmap(p,4);
 33         if(ret == -1)
 34         {
 35                 perror("mummap error");
 36                 exit(1);
 37         }
 38         close(fd);
 39         return 0;
 40 }

来源：CSDN

作者：YanWenCheng_

链接：https://blog.csdn.net/YanWenCheng_/article/details/103935650