Notepad ++ Regex：查找所有1和2个字母的单词

Question

I'm working with a text file with 200.000+ lines in Notepad++. Each line has only one word. I need to strip out and remove all words which only contains one letter (eg: I ) and words which contains only two letters (eg: as ).

I thought I could just pas in regular regex like this [a-zA-Z]{1,2} but I does not recognize anything (I'm trying to Mark them).

I've done manual search and I know that there do exists words of that length so therefor can it only be my regex code that's wrong. Anyone knows how to do this in Notepad++ ???

Cheers,
- Mestika

Answer 1

If you want to remove only the words but leave the lines empty, this works:

^[a-zA-Z]{1,2}$

Replace this with an empty string. ^ and $ are anchors for the beginning and the end of a line (because Notepad++'s regexes work in multi-line mode).

If you want to remove the lines completely, search for this:

^[a-zA-Z]{1,2}\r\n

And replace with an empty string. However, this won't work before Notepad++ 6, so make sure yours is up-to-date.

Note that you will have to replace \\r\\n with the specific line-endings of your file!

As Tim Pietzker suggested, a platform independent solution that also removes empty lines would be:

^[a-zA-Z]{1,2}[\r\n]+

A platform-independent solution that does not remove empty lines but only those with one or two letters would be:

^[a-zA-Z]{1,2}(\r\n?|\n)

Answer 2

我不使用Notepad ++，但我的猜测可能是因为你有太多的匹配 - 尝试包含单词边界（你的exp将匹配每组2个字母）

\b[a-zA-Z]{1,2}\b

Answer 3

The regex you specified should find 1-or-2 characters (even in Notepad++'s Find-dialog), but not in the way you'd think. You want to have the regex make sure it starts at the beginning of the line and ends at the end with ^ and $ , respecitevely:

^[a-zA-Z]{1,2}$

Notepad++ version 6.0 introduced the PCRE engine, so if this doesn't work in your current version try updating to the most recent.

Answer 4

You seem to use the version of Notepad++ that doesn't support explicit quantifiers: that's why there's no match at all (as { and } are treated as literals, not special symbols).

The solution is to use their somewhat more lengthy replacement:

\w\w?

... but that's only part of the story, as this regex will match any symbol, and not just short words. To do that, you need something like this:

^\w\w?$