使用 shell 脚本 (bash) 为特定接口查找我的系统的 ip 地址
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find ip address of my system for a particular interface with shell script (bash)
提问by Ayush joshi
I am trying to find ip-address of my own system through a shell script and write into a text thats my script content
我正在尝试通过 shell 脚本查找我自己系统的 ip 地址并写入我的脚本内容的文本
#!/bin/bash
wifiip=$(ip addr | grep inet | grep wlan0 | awk -F" " '{print }'| sed -e 's/\/.*$//')
eth0ip=$(ip addr | grep inet | grep eth0 | awk -F" " '{print }' | sed -e 's/\/.*$//')
if [ "$eth0ip" == "0" ]; then
echo "$eth0ip" | grep [0-9]$ > /home/pi/att/ip.txt
else
echo "$wifiip" | grep [0-9]$ > /home/pi/att/ip.txt
fi
and trying to do something like if one interface is not up print another ip in ip.txt
并尝试做一些事情，例如如果一个接口未启动，则在 ip.txt 中打印另一个 ip
but it's giving
但它给予
ip.sh: 14: [: unexpected operator
回答by Ed Morton
Let's clean up your code first. You don't need chains of a dozen different commands and pipes when you're already using awk. This:
让我们先清理你的代码。当您已经在使用 awk 时，您不需要十几个不同的命令和管道链。这个：
wifiip=$(ip addr | grep inet | grep wlan0 | awk -F" " '{print }'| sed -e 's/\/.*$//')
can be written simply as this:
可以简单地写成这样：
wifiip=$(ip addr | awk '/inet/ && /wlan0/{sub(/\/.*$/,"",); print }')
but your whole script can be written as just one awk command.
但是你的整个脚本可以写成一个 awk 命令。
I need you to update your question with some sample output of the ip addrcommand, the output you want from the awk command given that input, and explain more clearly what you're trying to do in order to show you the correct way to write that but it might be something like this:
我需要你用ip addr命令的一些示例输出更新你的问题，你想要的 awk 命令的输出给定该输入，并更清楚地解释你正在尝试做什么，以便向你展示正确的编写方法，但是它可能是这样的：
ip addr | awk '
/inet/ { ip[$NF] = ; sub(/\/.*$/,"",ip[$NF]) }
END { print ( "eth0" in ip ? ip["eth0"] : ip["wlan0"] ) }
' > /home/pi/att/ip.txt
回答by Jotne
Here is a nice way to get your IP address. This gives you the address used to reach the internet at the test, so it will give you correct IP even if you change from Wifi to eth or to any other IF type.
这是获取 IP 地址的好方法。这为您提供了在测试时用于访问互联网的地址，因此即使您从 Wifi 更改为 eth 或任何其他 IF 类型，它也会为您提供正确的 IP。
See more detailed post here: Linux bash script to extract IP address
在此处查看更详细的帖子：Linux bash script to extract IP address
my_ip=$(ip route get 8.8.8.8 | awk '/8.8.8.8/ {print $NF}')
To get interface name:
获取接口名称：
my_if=$(ip route get 8.8.8.8 | awk '/dev/ {f=NR} f&&NR-1==f' RS=" ")
