Regex: How to match instances of text, including spaces and new lines?

Question

I want a regular expression which will match one or more instances of text followed by a newline. Following the final match of text followed by a newline I would like for a single further newline, then no more. How would I go about achieving this?

I am having difficulty in enforcing the one new line rule.

My (wrong) attempts include: [^\n]+\n\n ([^\n]+\n[^\n]+)*\n\n

An example of text i would like to match is:

"Hello text\nMore text\nLast one\n\n"

With a non-match on both:

"Hello text\nMore text\nLast one\n\n\n"

"Hello text\nMore text\nLast one\n"

PLease help me. thanks

Please go read [ask]. The question title is far from good as well. — CBroe, Mar 21 '18 at 10:27
i am sorry @CBroe i will read and do this next time. Lance Toth see my attempts above — Dilwale dulhania, Mar 21 '18 at 10:29
Your question and your example do not match. You want the regex to match _some text including spaces, a new line_, and also 2 lines, right? So 4 full lines. — Robo Mop, Mar 21 '18 at 10:37

A. Bandtock · Accepted Answer · 2018-03-21T10:35:03.827

0

You're asking to match any number of lines of text, followed by only 1 additional newline at the end, simply: ^(.+\n)+\n(?!\n) will do what you'd like.

Example here: https://regex101.com/r/Hy3buP/1

Explanation:

^                        - Assert position at start of string
 (.+\n)+                 - Match any positive number of lines of text ending in newline
        \n               - Match the next newline
          (?!\n)         - Do a negative lookahead to ascertain there are no more newlines.

edited Mar 21 '18 at 10:35

answered Mar 21 '18 at 10:29

A. Bandtock

1,233
8
14

No, i want to match stuff mainly like "Hello text\nMore text\nLast one\n\n" – Dilwale dulhania Mar 21 '18 at 10:30
Ok, so only a single extra newline at the end? – A. Bandtock Mar 21 '18 at 10:32
I need to enforce only one newline per line (except the end where there need to be two consecutive ones) – Dilwale dulhania Mar 21 '18 at 10:32

Regex: How to match instances of text, including spaces and new lines?

1 Answers1