如何在另一个程序中使用1个程序的硬编码密钥（shmget调用）

I am new so I need some help. I want to hard code a no. of keys in program 1 and it chooses 1 key from them and use the key chosen by program 1 to be used program 2. Is there a way I can pass the same key to the other source file (program 2)?I am new so I need some help. I want to hard co