问题

I truly don't understand what I'm missing here.
我真的不明白我在这里漏掉了什么。

I have a very basic script that needs to check if text contains only numbers (more specifically, a semantic version for an app), then do some stuff.
我有一个非常基本的脚本，需要检查文本是否仅包含数字（更具体地说，是应用程序的语义版本），然后执行一些操作。

The text.txt is something like this:
text.txt的内容类似于这样：

appVersion: 2.0.1

and this is my script:
这是我的脚本：

#!/bin/bash
appVersion=`cat test.txt | awk '/^appVersion:/{print $2}'`
echo "appVersion is " $appVersion
Version=3.1.5

if [[ $appVersion =~ [0-9]+(\.[0-9]+){2,3}$ ]] ; then
    echo "is a number" $appVersion 
 else
    echo "not a number" $appVersion 
fi

Basically, I use cat to extract what I need from the text and then try to use that information in an if condition.
基本上，我使用cat从文本中提取我需要的内容，然后尝试在if条件中使用该信息。

The problem is the script is not consistently recognizing the variable $appVersion every time I run it. It keeps saying that there aren't any numbers in my variable, as if it's not matching the regex. However, if I pass the variable $Version, the script works.
问题在于，每次运行脚本时，脚本似乎不能始终识别变量$appVersion。它一直说我的变量中没有任何数字，就好像它不能匹配正则表达式一样。但是，如果我传递变量$Version，脚本就能正常工作。

By the way, the echo "appVersion is " $appVersion line is working (it's printing what I placed inside appVersion), so the command inside my variable $appVersion is actually retrieving what I need.
顺便说一下，echo "appVersion is " $appVersion这一行是有效的（它打印出了我放在appVersion中的内容），所以我的变量$appVersion内部的命令实际上是在检索我需要的内容。

I think I'm missing something with awk, but I cannot understand what.
我认为我在使用awk方面漏掉了一些东西，但我无法理解是什么。

Edit:
编辑：

I'm running this script on my local PC, on WSL2 Ubuntu 20, as a test, to later run it on a Linux Azure DevOps agent.
我正在本地PC上运行此脚本，在WSL2 Ubuntu 20上，作为测试，稍后将在Linux Azure DevOps代理上运行它。

#!/bin/bash
appVersion=`cat test.txt | awk '/^appVersion:/{print $2}'`
echo "appVersion is " $appVersion
Version=3.1.5

if [[ $appVersion =~ [0-9]+(\.[0-9]+){2,3}$ ]] ; then
    echo "is a number" $appVersion 
 else
    echo "not a number" $appVersion 
fi`

答案1

得分: 3

我建议替换

appVersion=`cat test.txt | awk '/^appVersion:/{print $2}'`

与

appVersion=$(awk '/^appVersion:/{print $2}' test.txt | dos2unix)

或者使用GNU的awk

appVersion=$(awk 'BEGIN{RS="\r\n"} /^appVersion:/{print $2}' test.txt)

以转换Windows的回车符。

参见：8 Powerful Awk Built-in Variables – FS, OFS, RS, ORS, NR, NF, FILENAME, FNR

appVersion=`cat test.txt | awk '/^appVersion:/{print $2}'`

appVersion=$(awk '/^appVersion:/{print $2}' test.txt | dos2unix)

appVersion=$(awk 'BEGIN{RS="\r\n"} /^appVersion:/{print $2}' test.txt)