运行守护进程后找不到守护进程日志

Question

这是我的守护进程:

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <syslog.h>
#include <string.h>

using namespace std;

#define DAEMON_NAME "vdaemon"

void process(){

    syslog (LOG_NOTICE, "Writing to my Syslog");
}   

int main(int argc, char *argv[]) {

    //Set our Logging Mask and open the Log
    setlogmask(LOG_UPTO(LOG_NOTICE));
    openlog(DAEMON_NAME, LOG_CONS | LOG_NDELAY | LOG_PERROR | LOG_PID, LOG_USER);

    syslog(LOG_INFO, "Entering Daemon");

    pid_t pid, sid;

   //Fork the Parent Process
    pid = fork();

    if (pid < 0) { exit(EXIT_FAILURE); }

    //We got a good pid, Close the Parent Process
    if (pid > 0) { exit(EXIT_SUCCESS); }

    //Change File Mask
    umask(0);

    //Create a new Signature Id for our child
    sid = setsid();
    if (sid < 0) { exit(EXIT_FAILURE); }

    //Change Directory
    //If we cant find the directory we exit with failure.
    if ((chdir("/")) < 0) { exit(EXIT_FAILURE); }

    //Close Standard File Descriptors
    close(STDIN_FILENO);
    close(STDOUT_FILENO);
    close(STDERR_FILENO);

    //----------------
    //Main Process
    //----------------
    while(true){
        process();    //Run our Process
        sleep(2);    //Sleep for 2 seconds
    }

    //Close the log
    closelog ();
}

我这样编译，

gcc vdaemon.cpp -o vdaemon

并运行它

./vdaemon 

然后当我得到

shishir@dewsworld:~/daemon$ ps -A | grep --color='auto' "vdaemon"
 5060 ?        00:00:00 vdaemon

然后我就没有日志了

shishir@dewsworld:~/daemon$ dmesg | grep --color='auto' "Writing to my Syslog"
shishir@dewsworld:~/daemon$ 

我需要知道如何获取日志。

Answer 1

我们建议您查看 /var/log/messages 区域以查看 syslog 守护程序将写入的位置。如果您仍然无法在那里找到您的消息，那么您应该查看您的系统日志守护程序的配置。它可能正在丢弃 LOG_NOTICE 消息或 LOG_USER 消息。您可以在系统级别配置 syslog 守护程序报告的内容。