在CSS文件中查找重复的十六进制值的正则表达式

Question

I have a large amount of CSS files that I've extracted the hex colour values from. What I'd like to do now is to strip out any duplicates not found by uniq. For example, I have:

#ccc
#cccccc
#eee
#eeeeee

What I'd like to do is to run a regular expression against the file to identify the #cccccc and #eeeeee (or any other similar) strings, remove the last three characters so I can then run uniq against them to remove the new duplicates.

How can I do this?

Thanks!

Answer 1

You could match (make sure it's case insensitive):

#([\da-f])\1([\da-f])\2([\da-f])\3\b

and replace it with:

#$1$2$3

For example in Perl written as:

s/#([\da-f])\1([\da-f])\2([\da-f])\3\b/#$1$2$3/gi

Example input:

#ccc
#cccccc
#123
#112233
#123123

Output:

#ccc
#ccc
#123
#123
#123123