使用systemd，程序崩溃后，自动重启

• 代码

设计了两种退出方式：exit和NULL崩溃。

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>

void sleep_second(int seconds)
{
    usleep(seconds*1000*1000);
}

#define NULL_EXCEPTION
#define LOG_FILE "/home/weiyu/service.log"

int main(int argc, char** argv)
{
    int count = 0;
    while (1)
    {
        int fd = open(LOG_FILE, O_RDWR|O_APPEND|O_CREAT, 0666);
        char data[128] = {0};
        count ++;

        sprintf(data, "count=%d\n", count);
        write(fd, data, strlen(data));

        if (count == 3) 
        {
#ifdef NULL_EXCEPTION
             sprintf(data, "count=3, NULL error and restart to 1\n");
#else
             sprintf(data, "count=3, exit(0) and restart to 1\n");
#endif

             write(fd, data, strlen(data));
        }

        close(fd);

        if (count == 3)
        {
#ifdef NULL_EXCEPTION
            char* pError = NULL;
            sprintf(pError, "EXCEPTION\n");
#else
            exit(0);
#endif
        }
        sleep_second(5); 
    }
    return 0;
}

• 编译

gcc test.cpp -o worker

• weiyu.service

[Unit]
Description=巍宇航天科技
After=systemd-user-sessions.service

[Service]
Type=simple
ExecStart=/home/weiyu/worker

KillSignal=SIGQUIT

# 重启模式是无论怎样都会重启这个程序，无法用 kill -9 杀死
Restart=always

# 这个表示重启的信号，也反过来映射的只有使用 systemctl stop  程序名，才能停止此程序
RestartPreventExitStatus=1 6 SIGABRT

• 复制

$ cp weiyu.service /etc/systemd/system

$ systemctl stop  weiyu.service
$ systemctl start weiyu.service