bash脚本在变量处使用cut命令，并将结果存储在另一个变量处 [英] bash script use cut command at variable and store result at another variable

问题描述

我有一个 config.txt 文件，其IP地址是这样的内容

I have a config.txt file with IP addresses as content like this

10.10.10.1:80
10.10.10.13:8080
10.10.10.11:443
10.10.10.12:80

我想 ping该文件中的每个ip 地址

#!/bin/bash
file=config.txt

for line in `cat $file`
do
  ##this line is not correct, should strip :port and store to ip var
  ip=$line|cut -d\: -f1
  ping $ip
done

我是一个初学者，很抱歉出现这样的问题，但我自己却找不到.

I'm a beginner, sorry for such a question but I couldn't find it out myself.

推荐答案

awk解决方案是我要使用的解决方案，但是如果您想了解bash的问题，请参见脚本的修订版.

The awk solution is what I would use, but if you want to understand your problems with bash, here is a revised version of your script.

#!/bin/bash -vx

##config file with ip addresses like 10.10.10.1:80
file=config.txt

while read line ; do
  ##this line is not correct, should strip :port and store to ip var
  ip=$( echo "$line" |cut -d\: -f1 )
  ping $ip
done < ${file}

您可以将顶行写为

for line in $(cat $file) ; do ...

您需要命令替换$( ... )来获取分配给$ ip的值

You needed command substitution $( ... ) to get the value assigned to $ip

通常使用while read line ... done < ${file}模式从文件中读取行更有效.

reading lines from a file is usually considered more efficient with the while read line ... done < ${file} pattern.

我希望这会有所帮助.

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