在AWK表达式中使用bash变量 [英] Use bash variable in AWK expression

问题描述

我在shell脚本中尝试了以下代码段，但awk找不到$REF

I tried the following snippet in a shell script but awk didn't find $REF

REF=SEARCH_TEXT
echo "some text" | awk '/$REF/{print $2}'

推荐答案

您的问题的措辞是真的很差...

You question is worded really poor...

无论如何，我想你想要这个:

Anyway, I think you want this:

REF=SEARCH_TEXT
echo "some text" | awk "/$REF/{print \$2}"

请注意$2的转义和双引号.

Note the escaping of $2 and the double quotes.

或者这个:

REF=SEARCH_TEXT
echo "some text" | awk "/$REF/"'{print $2}'

请注意谨慎使用双引号和单引号，并且不要在$2上转义.

Note the judicious use of double and single quotes and no escaping on $2.

您必须使用shell扩展，否则将包括导出shell变量并从awk的环境中使用它-在这种情况下，这是 overkill :

You have to use shell expansion, as otherwise it would encompass exporting a shell variable and using it from the environment with awk - which is overkill in this situation:

export REF=SEARCH_TEXT
echo "some text" | awk '{if (match($0, ENVIRON["REF"])) print $2}'

我认为awk不支持/.../卫队中的变量. 如果我错了，请纠正我.

I think awk does not support variables in /.../ guards. Please correct me if I'm wrong.

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