如何在 Arch Linux 的登录屏幕上显示 IP

Question

我可以通过编辑文件在 Ubuntu 中执行以下操作：

/etc/rc.local

并添加：

IP=$(/sbin/ifconfig eth0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}')

echo "IP: $IP" > /etc/issue

在 Arch 中，这个文件不存在“/etc/rc.local”，经过一番搜索，我发现我必须创建这个文件：

/etc/systemd/system/rc-local.service

内容：

[Unit]
Description=/etc/rc.local compatibility

[Service]
Type=oneshot
ExecStart=/etc/rc.local

TimeoutSec=0
StandardOutput=tty
RemainAfterExit=yes
SysVStartPriority=99

[Install]
WantedBy=multi-user.target

然后创建“/etc/rc.local”。

内容：

IP=$(/sbin/ip route get 1 | awk '{print $NF;exit}')
echo "IP: $IP" > /etc/issue

exit 0

然后使其可执行：

sudo chmod +x /etc/rc.local

最后开始/测试：

sudo systemctl start rc-local.service

得到错误：

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

的输出systemctl status rc-local.service：

* rc-local.service - /etc/rc.local Compatibility
Loaded: loaded (/etc/systemd/system/rc-local.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Fri 2016-06-10 02:52:17 AST; 1min 59s ago
Process: 760 ExecStart=/etc/rc.local (code=exited, status=203/EXEC)

Jun 10 02:52:17 maro systemd[1]: Starting /etc/rc.local Compatibility...
Jun 10 02:52:17 maro systemd[1]: rc-local.service: Control process exited, code=exited status=203
Jun 10 02:52:17 maro systemd[1]: Failed to start /etc/rc.local Compatibility.
Jun 10 02:52:17 maro systemd[1]: rc-local.service: Unit entered failed state.
Jun 10 02:52:17 maro systemd[1]: rc-local.service: Failed with result 'exit-code'.

的输出journalctl -xe：

-- Unit rc-local.service has begun starting up.
Jun 10 02:52:17 maro systemd[760]: rc-local.service: Failed at step EXEC spawning /etc/rc.local: Exec format error
-- Subject: Process /etc/rc.local could not be executed
-- Defined-By: systemd

更新：

1. 添加#!/bin/bash到/etc/rc.local
2. sudo systemctl daemon-reload
3. sudo systemctl start rc-local.service
4. 现在我没有收到任何错误！但：

5. sudo systemctl status rc-local.service 输出：

   rc-local.service - /etc/rc.local Compatibility Loaded: loaded (/etc/systemd/system/rc-local.service; enabled; vendor preset: disabled) Active: inactive (dead) since Fri 2016-06-10 13:13:04 AST; 3s ago Process: 488 ExecStart=/etc/rc.local (code=exited, status=0/SUCCESS)

   Jun 10 13:13:04 maro systemd[1]: Starting /etc/rc.local Compatibility... Jun 10 13:13:04 maro systemd[1]: Started /etc/rc.local Compatibility.

尝试重新启动并在登录前显示：

rtnetlink answers network is unreachable

在登录界面：只显示“IP:”，不显示机器IP。例如，一旦登录并 ping google，互联网就可以正常工作，并且可以通过 LAN 访问机器。

---

1. sudo env -i /etc/rc.local = 无输出
2. ip route get 1 | awk '{print $NF;exit}'用于/etc/rc.local= 192.168.0.103

的输出nav：

XDG_SESSION_ID=c2
TERM=xterm
SHELL=/bin/bash
SSH_CLIENT=192.168.0.100 64436 22
SSH_TTY=/dev/pts/0
USER=maro
MAIL=/var/spool/mail/maro
PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl
PWD=/home/maro
LANG=C
SHLVL=1
HOME=/home/maro
LOGNAME=maro
DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
SSH_CONNECTION=192.168.0.100 64436 192.168.0.103 22
XDG_RUNTIME_DIR=/run/user/1000
_=/usr/bin/env

编辑/etc/systemd/system/rc-local.service：在 ExecStart 之后删除了四个设置。我也试过改变： Type=forking

状态仍然说： Active: inactive (dead)

Answer 1

在CentOS 7和Debian 8（也许还有其他）上，只需将以下行附加到/etc/issue

My IP address: \4

这将解析为机器的 IPv4 地址。如果你有多个网络接口并且你想选择一个特定的，你可以用

My IP address: \4{eth0}