Shared Memory With Two Processes In C?

Question

I want to do the following:

Parent process creates a child process. Then the child process reads n int\'s from the user and store them in a shared memory. The parent

Answer 1

My problem was so stupid. I need to provide the Child process with the ability to write into the SHM. This line in the if-block :

shmid = shmget(2009, SHMSIZE, 0);

Will become like this:

shmid = shmget(2009, SHMSIZE, 0666 | IPC_CREAT);

Thanks to you all and especially to @JoachimPileborg :)