Linux (C) 信号处理

Question

我的简单代码将捕获所有信号并显示您在确切时间触发的信号，但我的问题是当信号被捕获时代码将结束并且我无法触发其他 SIGINT 的任何其他信号我该如何触发喜欢 (SIGSEGV , SIGABRT)

#include<stdio.h>
#include<time.h>
#include<signal.h>
#include<unistd.h>
//bos501_hw_signals_handling_Linux
void sig_handler(int signo)
{ time_t current_time;
    char* c_time_string;
    //Catch the current time. /
    current_time = time(NULL);
    // Convert to local time  /
    c_time_string = ctime(&current_time);
//putting a condition for signals when they are caught to print the signal.
    if (signo == SIGINT)
printf("received SIGUSR1\n"" ::Current time is %s", c_time_string);
    else if (signo == SIGSEGV)
printf("received SIGSEGV\n"" ::Current time is %s", c_time_string);
    else if (signo == SIGABRT)
printf("received SIGABRT\n"" ::Current time is %s", c_time_string);
    else if (signo == SIGKILL)
printf("received SIGKILL\n"" ::Current time is %s", c_time_string);
    else if (signo == SIGSTOP)
printf("received SIGSTOP\n"" ::Current time is %s", c_time_string);
}

int main(void)
{    //putting a conditon to show the signal that isnt caught like (SIGKILL,SIGSTOP)
    if (signal(SIGUSR1, sig_handler) == SIG_ERR)
        printf("\ncan't catch SIGUSR1\n");
    if (signal(SIGSEGV, sig_handler) == SIG_ERR)
        printf("\ncan't catch SIGSEGV\n");
    if (signal(SIGABRT, sig_handler) == SIG_ERR)
        printf("\ncan't catch SIGABRT\n");
    if (signal(SIGKILL, sig_handler) == SIG_ERR)
        printf("\ncan't catch SIGKILL\n");
    if (signal(SIGSTOP, sig_handler) == SIG_ERR)
        printf("\ncan't catch SIGSTOP\n");
    // long wait to process the signal 
    while (1)
        sleep(1);
    return 0;
    //end of code
}

Answer 1

1. SIGKILL 和 SIGSTOP 信号不能被捕获、阻止或忽略。对于这些，默认操作总是发生。

2. 不推荐使用信号系统调用。使用 sigaction 系统调用来设置信号动作。

3. printf 不应在信号处理程序中使用。请改用文件描述符 2 上的 write 系统调用。