#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
void catchsignal(int signo) {
char handmsg[] = "You cannot \"Ctrl-C\" me!\n";
int msglen = sizeof(handmsg);
write(STDERR_FILENO, handmsg, msglen);
}
int main() {
struct sigaction act;
act.sa_handler = catchsignal;
act.sa_flags = 0;
if ((sigemptyset(&act.sa_mask) == -1) ||
(sigaction(SIGINT, &act, NULL) == -1)) {
printf("Failed to set SIGINT to handle Ctrl-C");
}
while(1);
}
that program catches the signal Ctrl C which if I'm not mistaken is one of the kill commands in linux. i can't remember what specific kill command is that. my question is how does the catchsignal function learn which signal to ignore? thanks.
Last edited by blowtorch; 12-11-2006 at 05:22 AM..
This bunch of statements is where the signal handler is being setup. The "act.sa_handler=catchsignal;" statement spells out the function that will be used (catchsignal). And the statement signaction(SIGINT,&act,NULL) specifies that values from the act structure are to be associated with the reception of SIGINT.
This bunch of statements is where the signal handler is being setup. The "act.sa_handler=catchsignal;" statement spells out the function that will be used (catchsignal). And the statement signaction(SIGINT,&act,NULL) specifies that values from the act structure are to be associated with the reception of SIGINT.
