Characteristics of the parent-child process capture signal

After experiment: Except for 2 signals that cannot be captured

As long as the parent process does not define the signal, when the signal is captured, the parent is processed by default

The parent process is defined, the child process is undefined, and the parent process is handled as defined, and the child process is handled by default;

Both parent and child processes are defined and captured to be handled in their own way.

Characteristics of the parent-child process capture signal