grep中哪个空白是最佳标准? [英] Which white space in grep is the best standard?

问题描述

我需要找到一个在文件中用空格括起来的单词.

I needed to find a word which is enclosed by white spaces in a file.

文件test.txt

A file, test.txt

head target_word tail

上面的单词之间的空格可以是制表符.我尝试过

Spaces between words above can be tab. And I tried

grep -e '\starget_word\s' test.txt

找不到"target_word".但是

It failed to find "target_word". But

grep -e "[[:space:]]target_word[[:space:]]" test.txt

和

grep -e "[ \t]target_word[ \t]" test.txt

运作良好.

哪个空白是最可接受的空格?请让我知道.

Which white space is the most acceptable one? Please let me know.

推荐答案

要匹配空格或制表符，可以使用 [[:: blank:]] .不管区域设置如何，都将其定义为空格或制表符.

To match either a space or a tab, you can use [[:blank:]]. This is defined as either a space or a tab, regardless of the locale settings.

来自 POSIX规范:

在POSIX语言环境中，仅应包含< space> 和< tab> .

在语言环境定义文件中，< space> 和< tab> 会自动包含在此类中.

In a locale definition file, the <space> and <tab> are automatically included in this class.

您还可以使用 [[:: space:]] ，但这除了空格和制表符之外，还包含其他字符.

You can also use [[:space:]] but this contains other characters in addition to spaces and tabs.

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