What is the output of this program?

#include<stdio.h>
#include<signal.h>
 
void response (int);
void response (int sig_no)
{
    printf("%s\n",sys_siglist[sig_no]);
}
int main()
{
    pid_t child;
    int status;
    child = fork();        
    switch(child){
        case -1:
            perror("fork");
        case 0:
            break;               
        default :
            signal(SIGCHLD,response);
            wait(&status);
            break;
    }
}