REGEX - Matching again multiple lines

Question

Given text like:

XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX.XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX.XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX. XXXXXXX.

Boss: asdasdasdasd
Date: XXX, XXXXXXXXX

I want to match the last 3 lines:

Here's what I'm trying but it's failing:

^Boss:.*$^Date:.*$

Suggestions? Thanks

Why does it have to be done with a regex? Just split on newlines. — Matt Ball, Feb 12 '11 at 00:38
+1 @Matt Ball, why does everything look like it needs to be hit with the regex hammer? — the Tin Man, Feb 12 '11 at 01:42

score 2 · Accepted Answer · answered Feb 12 '11 at 00:55

2

You might need to skip the first x lines... also you anchor ^ is probably causing you not to match.

Try

(?:.*[\r\n]*)*Boss:.*(?:.*[\r\n]*)Date:.*

answered Feb 12 '11 at 00:55

John Sobolewski

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score 2 · Answer 2 · answered Feb 12 '11 at 03:49

^Boss:.*[\r\n]+Date:.*$

The line anchors, ^ and $, are zero-width assertions; they assert that some condition holds true without consuming any characters.

^ means the current position is either the beginning of the input, or it's immediately preceded by a line separator.
$ means the current position is either the end of the input, or it's immediately followed by a line separator.

But neither of them consumes the line separator, so $^ can never match. [\r\n]+ matches (and consumes) one or more carriage-returns or linefeeds, so it handles the three most common types of line separator: \r (older Mac standard), \r\n (Windows/network standard), and \n (Unix/Linux/Mac OS X/pretty much everything else).

score 0 · Answer 3 · answered Feb 12 '11 at 00:57

0

If your file is not of size in GB range

ruby -e 'a=File.read("file"); p a.split(/\n/)[-3..-1] '

answered Feb 12 '11 at 00:57

kurumi

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REGEX - Matching again multiple lines

3 Answers3

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