PracticeDev/study_clang/ipc_test/shared_mem/ipc_share_mem_posix_read.c

29 lines
746 B
C

/*************************************************************************
> File Name : ipc_share_mem_posix_read.c
> Author : TL Song
> EMail : songtianlun@frytea.com
> Created Time : Wed 30 Dec 2020 03:22:20 PM CST
************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
int main(int argc, char ** argv)
{
int fd = shm_open("posixsm", O_RDONLY, 0666);
ftruncate(fd, 0x400000);
char *p = mmap(NULL, 0x400000, PROT_READ, MAP_SHARED, fd, 0);
int i = 0;
for(i = 0 ;i < 100; i++)
{
printf("Read '%c' in mem '%p'\n", *p, p);
sleep(1);
}
munmap(p, 0x400000);
return 0;
}