Re: match across line using grep
On 2010年08月04日 00:57, Bob McGowan wrote:
> I would suspect
> the regex engine is still honoring '. (dot) does not match newline'
> convention but is OK with literals, if present.
>
It can be a bug in grep implementation.
If your theory holds true, the following should match, but it doesn't.
$ printf "a\nb" | grep -z 'a[^a]*b'
$
Because, if dot does not match newline, like in Java (verified in
Java-based JEdit editor), then dot is equal to
[^\n]
In that case a easy way to workaround it is to replace dot with
[^[:something-horribly-non-existent:]]
P.S. A interesting design might be: for an RE implementation where dot
does not match newline, the very RE implementation should allow [^] to
mean really "matches anything". But the java people didn't do so, they
introduced "DOTALL" mode, if you enter this mode, dot means anything,
otherwise it means [^\n]. This new mode only makes things more
complicated to my understanding.
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