如何使 grep [AZ] 独立于语言环境？
我每天都在做一些 grep 操作，突然发现一些看似微不足道的东西不起作用：
$ echo T | grep [A-Z]
没有匹配项。
为什么T不在AZ范围内？
我稍微改变了正则表达式：
$ echo T | grep [A-Y]
匹配！
哇！为什么 T 在 AY 内但不在 AZ 内？
显然这是因为我的环境设置为爱沙尼亚语言环境，其中 Y 位于字母表的末尾，而 Z 位于中间的某个位置： ABCDEFGHIJKLMNOPQRSŠZŽTUVWÕAUÜXY
$ echo $LANG
et_EE.UTF-8
这一切都让我感到有点震惊。 99% 的时间我都是 grep 计算机代码，而不是爱沙尼亚文献。我一直以来都以错误的方式使用 grep 吗？我过去曾因此犯过哪些错误？
在尝试了几件事之后，我得到了以下解决方案：
$ echo T | LANG=C grep [A-Z]
这是使 grep 区域设置独立的推荐方法吗？
此外...定义这样的别名是否安全：
$ alias grep="LANG=C grep"
PS . 我还想知道为什么像 [AZ] 这样的字符范围首先依赖于语言环境，而 \w 似乎不受语言环境的影响（尽管手册说 \w 是等效的[[:alnum:]] - 但我发现后者取决于语言环境，而 \w 则不然）。
I was doing some everyday grepping and suddenly discovered that something seemingly trivial does not work:
$ echo T | grep [A-Z]
No match.
How come T is not within A-Z range?
I changed the regex a tiny bit:
$ echo T | grep [A-Y]
A match!
Whoa! How is T within A-Y but not within A-Z?
Apparently this is because my environment is set to Estonian locale where Y is at the end of the alphabet but Z is somewhere in the middle: ABCDEFGHIJKLMNOPQRSŠZŽTUVWÕÄÖÜXY
$ echo $LANG
et_EE.UTF-8
This all came as a bit of a shock to me. 99% of the time I grep computer code, not Estonian literature. Have I been using grep the wrong way all the time? What all kind of mistakes have I made because of this in the past?
After trying several things I arrived at the following solution:
$ echo T | LANG=C grep [A-Z]
Is this the recommended way to make grep locale-independent?
Further more... would it be safe to define an alias like that:
$ alias grep="LANG=C grep"
PS. I'm also wondering of why are the character ranges like [A-Z] locale dependent in the first place while \w seems to be unaffected by locale (although the manual says \w is equivalent of [[:alnum:]] - but I found out the latter depends on locale while \w does not).
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POSIX 正则表达式（Linux 和 FreeBSD grep 自然支持，以及其他一些根据请求支持）具有一系列尊重语言环境的 [:xxx:] 模式。有关详细信息，请参阅手册页。
由于 [] 是模式名称的一部分，因此您还需要外部 []，无论它看起来多么奇怪。
随着这些 : 代码的出现，经典的 \w 等代码仍然严格保留在 C 语言环境中。因此，您对模式的选择决定了 grep 是否使用当前区域设置。
[AZ] 应遵循区域设置，但您可能需要设置 LC_ALL 而不是 LANG，特别是当系统将 LC_ALL 设置为不同的值时。
POSIX regular expressions, which Linux and FreeBSD grep support naturally, and some others support on request, have a series of [:xxx:] patterns that honor locales. See the man page for details.
As the []s are part of the pattern name you need the outer [] as well, regardless of how strange it looks.
With the advent of these : codes the classic \w, etc., remain strictly in the C locale. Thus your choice of patterns determines if grep uses the current locale or not.
[A-Z] should follow locale, but you may need to set LC_ALL rather than LANG, especially if the system sets LC_ALL to a different value for your.