linux 信号

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>

char buf[1024];

void signal_handler(int type)
{
	switch (type)
	{
	case SIGINT:
		printf("catch SIGINT\n");
		//write(STDOUT_FILENO,"catch SIGINT\n",sizeof("catch SIGINT\n"));
		break;
		//kill信号是不可捕捉的，默认退出的，这儿这样写没有用
	case SIGKILL:
		printf("catch SIGKILL\n");
		//write(STDOUT_FILENO,"catch SIGKILL\n",sizeof("catch SIGKILL\n"));
		break;
	case SIGALRM:
		printf("catch SIGALRM\n");
		//write(STDOUT_FILENO,"catch SIGALRM\n",sizeof("catch SIGALRM\n"));
		break;
	default:
		printf("catch unrecognized signal\n");
		//write(STDOUT_FILENO,"catch unrecognized signal\n",sizeof("catch unrecognized signal\n"));
		break;
	}
}

int main(int argc, char *argv[])
{
	memset(buf, 0, sizeof(buf));

	signal(SIGINT, signal_handler);
	signal(SIGKILL, signal_handler);
	signal(SIGALRM, signal_handler);
	int i = 0;
	char s[128];
	memset(s, 0, sizeof(s));
	while (1)
	{
		sprintf(s, "SIGINT = %d,SIGKILL = %d,SIGALRM = %d,index = %d\n", SIGINT, SIGKILL, SIGALRM, i++);
		write(STDOUT_FILENO, s, sizeof(s));
		pause();
	}
	exit(0);
}