捕捉Ctrl+C( INT)
程序代码：#include <stdio.h>
#include <unistd.h>
#include <signal.h>
/* first, here is the signal handler */
void catch_int(int sig_num) {
/* re-set the signal handler again to
* catch_int, for next time
*/
signal(SIGINT, catch_int);
printf("Dont't do that\n");
fflush(stdout);
}
int main(int argc, char *argv[]) {
/* set the INT (Ctrl-C) signal handler to
* 'catch_int
*/
signal(SIGINT, catch_int);
/* now, lets get into an infinite loop of doing
* nothing
*/
for( ; ; )
pause();
}