Question

Which of the following functions can be performed using signal system call?

(a) ignore the signal

(b) restore the default

(c) invoke a signal handling function

(d) ignore the signal, restore the default and invoke a signal handling function

The question was posed to me during an internship interview.

This intriguing question comes from Performance Components and Tools in portion System Programming II – Process Control & Unix System Performance of Unix

Answer 1

The correct choice is (d) ignore the signal, restore the default and invoke a signal handling function

To explain: signal system call doesn’t generate any signal but only specifies its disposition. Using signal call we can either ignore the signal, restore the default (if it was changed earlier) or invoke a signal handling function.