linux守护进程start-stop-daemon启动服务

红太狼 2021-12-21 05:34 378阅读 0赞

**start-stop-daemon**

#! /bin/sh
    
    PATH=/sbin:/bin
    
    . /lib/lsb/init-functions
    
    do_start () { 
       log_action_msg "do_start tftp here"
    
       if start-stop-daemon --start --background --pidfile /var/run/tftp.pid \
       --exec /home/zxc/tftp/tftps; then               
          log_action_msg "do_start succ"
          log_end_msg 0 || true
       else
          log_action_msg "do_start error"
          log_end_msg 1 || true
       fi
    }
    
    do_stop () { 
       log_action_msg "do_stop tftp here"
    
       if start-stop-daemon start-stop-daemon --stop --name tftps; then
          log_action_msg "do_stop succ"
          log_end_msg 0 || true
       else
          log_action_msg "do_stop error"
          log_end_msg 1 || true
       fi
    }
    
    case "$1" in
       start)
          do_start
          ;;
       restart|reload|force-reload)
          echo "Error: argument '$1' not supported" >&2
          exit 3
          ;;
       stop)
          do_stop
          ;;
       status)
          status_of_proc -p /var/run/tftp.pid /home/zxc/tftp/tftps tftps \
          && exit 0 || exit $?
          ;;
       *)
          echo "Usage: $0 start|stop" >&2
          exit 3
          ;;
    esac

**/var/run/\*.pid**

#define PID_FILE "/var/run/tftp.pid"
    
    int lock_file(int fd)
    { 
        struct flock fl;
        fl.l_type = F_WRLCK;
        fl.l_start = 0;
        fl.l_whence = SEEK_SET;
        fl.l_len = 0;
    
        return (fcntl(fd, F_SETLK, &fl));
    }
    
    int alone_runnind(void)
    { 
        int fd;
        char buf[16];
    
        fd = open(PID_FILE, O_RDWR | O_CREAT, 0666);
        if (fd < 0)
        { 
            perror("open");
            exit(1);
        }
    
        if (lock_file(fd) < 0)
        { 
            if (errno == EAGAIN)
            { 
                close(fd);
                printf("alone runnind\n");
                return -1;
            }
    
            printf("can't lock %s: %s\n", PID_FILE, strerror(errno));
        }
    
        ftruncate(fd, 0);
        sprintf(buf, "%ld\n", (long)getpid());
        write(fd, buf, strlen(buf));
    
        close(fd);
    
        return 0;
    }