Grep中“词"的含义 [英] The meaning of 'word' in Grep

问题描述

在 grep 的手册页中，它说:

In the man page for grep it says that:

> The symbols < and > respectively match the empty string at the
> beginning and end of a word.

这里的词是什么意思?

我知道这个词是在 -w 中定义的，但这里有证据表明它在这种情况下具有不同的含义:

I know that word is defined in -w, but here is the proof that it has a different meaning in this context:

如果文件 'test' 包含 hi/，并且我 grep -w 'hi/' test，我得到一个匹配，但是如果我 grep 'hi/>'测试，我没有.

If file 'test' contains hi/, and I grep -w 'hi/' test, I get a match, but if I grep 'hi/>' test, I don't.

推荐答案

单词的开头是单词字符(字母、数字或下划线)，前面没有另一个单词字符，单词的结尾是一个单词字符，后面没有另一个单词字符.那么单词"就是一系列单词字符.

The beginning of a word is a word character (a letter, number, or underscore) that is not preceded by another word character, and the end of a word is a word character that is not followed by another word character. A "word" is then just a series of word characters.

hi/> 不匹配 hi/ 的原因是因为 > 前面是一个非单词字符 (/)，所以它不能是词尾的位置.

The reason hi/> doesn't match hi/ is because the > is preceded by a non-word character (/), and so that can't be the location of an end-of-word.

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