syntax of sigchld and its declaration

Question

On compiling my C program for implementing multiple client server chat program using UDP ,i got some errors..I was able to correct some of them, but cannot do with some others.. They are....:

1) unknown type name sig_atomic_t

2) storage size of sigchild_action isn't known

3) SIGCHLD undeclared (first use in this function)

4) SIGUSR2 undeclared (first use in this function)

I dont know how to solve this errors...I tried a lot, but was not able to find anywhere the syntax of sigchild....n know about how to declare it...Please do help me.....

Answer 1

What about including the appropriate header:

#include <signal.h>

Does that help?