我制作了这段代码,我必须使用警报信号( SIGALRM
)让程序打印消息“我还活着”。每 3 秒。
但它不起作用,它仅在我按下 CTR-C 时发送消息“我还活着”,我猜
我没有把 SIGALRM 函数放在正确的地方,你能帮我吗?
#include <stdlib.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
unsigned Count = 0; //Counts the number of times it receives the signal SIGINT.
void mypause(int sign); //prototype of the function my pause.
void mypause(int sign) {
signal(SIGALRM, mypause); //Set alarm clock for 3 seconds.
alarm(3);
printf("I'm Alive");
signal(SIGINT, mypause);
switch (sign) {
case SIGINT:
printf("\nPressed CTR-C\n");
printf("I'm running, waiting for a sign\n");
Count++;
break;
case SIGQUIT:
printf("\nPressed CTR-\\n");
printf("You pressed CTR-C %d times", Conta);
exit(0); //Exit program.
break;
}
}
int main() {
signal(SIGALRM, mypause);
signal(SIGINT, mypause);
signal(SIGQUIT, mypause);
printf("\nI'm running waiting for a signal\n");
while (1) {}
return (0);
}
最佳答案
也许在您的 alarm(3)
中添加 main()
?
关于c - 如何正确使用 SIGALRM?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/16024774/