From: Markus Schirp <mbj@...>
Date: 2008-09-29T07:41:41+09:00
Subject: multiline regexp and newlines

Hello Community,

Im trying to reject any newline in a string using regexp. 
The string must not be empty.

Yes, this can be done without regexp.

So my Regexp is like:

"Match any character from the begin to the end of a string witch is not
newline, and ensure there is at least one character, and to this match
over multiple lines (so if there are multiple lines reject it)"

Results in /^[^\n]+$/m

My ruby 1.8.6 does:

/^[^\n]+$/m =~ "a\n" -> 0

without multiline flag the same:

/^[^\n]+$/ =~ "a\n" -> 0

But:

/^[^\n]+$/m =~ "\n" -> nil

If I replace "reject newline" with "reject character x" it worked as
expected (x is 'a' in this example):

/^[^a]+$/m =~ "ba" -> nil

Is the multiline-regexp implementation broken or my multiline behaviour
expectation?

Mfg

Markus Schirp