通过端口号查找进程ID

Question

我正在尝试（目前收效甚微）在我的 Fedora 24 服务器上设置 Dovecot 邮件服务器。我已经安装了 Dovecot 并设置了 conf 文件，一切都很好。但是当我运行时：

systemctl restart dovecot

编辑 conf 文件后，我收到此消息

Job for dovecot.service failed because the control process exited with error code. See "systemctl status dovecot.service" and "journalctl -xe" for details

跑步systemctl status dovecot.service给了我一个不同的错误

[root@fedora app]# systemctl status dovecot.service
? dovecot.service - Dovecot IMAP/POP3 email server
   Loaded: loaded (/usr/lib/systemd/system/dovecot.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Tue 2016-08-16 15:02:30 UTC; 37min ago
     Docs: man:dovecot(1)
           http://wiki2.dovecot.org/
  Process: 11293 ExecStart=/usr/sbin/dovecot (code=exited, status=89)
  Process: 11285 ExecStartPre=/usr/libexec/dovecot/prestartscript (code=exited, status=0/SUCCESS)

Aug 16 15:02:30 fedora dovecot[11293]: Error: service(imap-login): listen(*, 993) failed: Address already in use
Aug 16 15:02:30 fedora dovecot[11293]: master: Error: service(imap-login): listen(*, 993) failed: Address already in use
Aug 16 15:02:30 fedora dovecot[11293]: Error: service(imap-login): listen(::, 993) failed: Address already in use
Aug 16 15:02:30 fedora dovecot[11293]: master: Error: service(imap-login): listen(::, 993) failed: Address already in use
Aug 16 15:02:30 fedora dovecot[11293]: Fatal: Failed to start listeners
Aug 16 15:02:30 fedora dovecot[11293]: master: Fatal: Failed to start listeners
Aug 16 15:02:30 fedora systemd[1]: dovecot.service: Control process exited, code=exited status=89
Aug 16 15:02:30 fedora systemd[1]: Failed to start Dovecot IMAP/POP3 email server.
Aug 16 15:02:30 fedora systemd[1]: dovecot.service: Unit entered failed state.
Aug 16 15:02:30 fedora systemd[1]: dovecot.service: Failed with result 'exit-code'.

我尝试运行，lsof -i | grep 993但这不会产生任何进程。知道如何解决这个问题吗？

Answer 1

netstat当您尝试解决许多与网络相关的问题时，它是您的朋友。要找到侦听端口，我会使用netstat -tulpn | grep :<port number>

例如，要查找端口 22 上侦听的 pid，我将运行：

netstat -tulpn | grep :22
tcp  0  0 0.0.0.0:22    0.0.0.0:*    LISTEN      3062/sshd

这告诉我 pid 为 3062 的 sshd 正在侦听端口 22。