信号（一）

1 信号函数

代码示例

#include "ourhdr.h"
#include "signal.h"

static void	sig_usr(int);	/* one handler for both signals */

int
main(void)
{
	if (signal(SIGUSR1, sig_usr) == SIG_ERR)
		err_sys("can't catch SIGUSR1");
	if (signal(SIGUSR2, sig_usr) == SIG_ERR)
		err_sys("can't catch SIGUSR2");
	for ( ; ; )
		pause();
}

static void
sig_usr(int signo)		/* argument is signal number */
{
	if (signo == SIGUSR1)
		printf("received SIGUSR1
");
	else if (signo == SIGUSR2)
		printf("received SIGUSR2
");
	else
		err_dump("received signal %d
", signo);
}

运行结果：

[root@rac1 signal]# ./a.out  &
[1] 10516
[root@rac1 signal]# kill -USR1 10516
received SIGUSR1
[root@rac1 signal]# kill -USR2 10516
[root@rac1 signal]# received SIGUSR2

[root@rac1 signal]# kill 10516
[root@rac1 signal]# 
[1]+  Terminated              ./a.out