如何使用grep和regex查找双引号字符串？

Question

I'm trying to find all the occurrences of the string "5.1" in all files under a certain directory. I've tried using the following command but it finds none:

#grep -Re[5]+\.+[1] .

What am I doing wrong?

Answer 1

您不需要e正则表达式，因此fgrep构造起来更简单，执行起来也更快

fgrep -R '"5.1"' .

Answer 2

Your expression doesn't make sense to me. It seems like you're looking for:

grep -R '5\.1' .

Or if you want to include the " characters:

grep -R '"5\.1"' .

But I don't see anything related to those in your original post, so it's hard to say.

Answer 3

Looking for a fixed string recursively would be

grep -fR '"5.1"' .

(if you really meant including the double quotes).

Note that the -R option is not POSIX, so may not be available. In that case, the portable solution is

find . -type f | xargs grep -f '"5.1"'