Linux Process life

With a fork statement, a new process is born, but it is only a clone of the old process.

Then, with exec, the new process was reborn and independent from home, and started a career serving the people.

A person is dead, and the process is the same. It can be a natural death, that is, the last "}" that runs to the main function. It can also be a suicide, there are two ways to commit suicide
One is to call the exit function, and the other is to use return in the main function. In any way, it can leave a suicide note and keep it in the return value; it can even be murdered,
Other processes end their lives in other ways.

After the process dies, a zombie will be left behind. Wait and waitpid act as the zombie and push the zombie to be credened, making it invisible.

This is the complete life of the process.