Shmat permission denied Solution

The memory can be shared between processes through a series of functions such as shmget/shmat.

With reference to these blogs, we can achieve:

Http://nnssll.blog.51cto.com/902724/199808 (the original is wrong, pay attention to view the comment)

Http://wellwy.blog.51cto.com/1609602/492083

However, some difficulties were encountered during the attempt:

Shm_addr = (char *) shmat (shm_id, null, 0 );-1 is returned.

Perror:Permission denied

I checked some information on the Internet, saying that I had to add 0666 permissions to shmget, for example:

Shm_id = shmget (Key, 4096, ipc_creat |0666);

But it still does not work.

When I thought about ftok, I used a filepath.

Key = ftok (filepath, 0 );

This ftok must already have a real file. Is it a File Permission problem?

After chmod 777 filepath is used, it is enough...

If not, you can run sudo.ProgramTry it.