Re: RegEx: How to negate more than one character?

I recommend reading perlrequick and perlretut to gather some insight on how regular expressions work.

Nevertheless, here's a possible implementation:

my $re = qr/(?:a|b)h/;

print 'abcdef' !~ $re;
print 'ahcdef' !~ $re;
print 'abbhef  !~ $re;
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yields

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Re^2: RegEx: How to negate more than one character? by lokiloki (Beadle) on Mar 25, 2007 at 23:15 UTC
thanks... but I am looking for the particular negation to be part of a much more complex overall regular expression... i.e., how can i do the negation within the expression itself, rather than relying on `!~`? What I am trying to do is match outermost `<% ... %>` "brackets" while also handling possible internal pairs of my own unique bracketing system: `$re = qr{\<\%(?:(?>[^(\<\%\|\%\>)]+)\|(??{$re}))\%\>};` [download] I guess what I am looking for is a replacement to the `[^(\<\%\|\%\>)]+` part above (unless that is correct).	[reply] [d/l] [select]
Re^3: RegEx: How to negate more than one character? by jettero (Monsignor) on Mar 25, 2007 at 23:34 UTC
You can proably use a negatively asserted look ahead: `$str =~ m/$pattern(?!ab\|cd)$morepattern/;`. It is a zero-width pattern, but it might do what you want. It's about half-way through perlre. -Paul	[reply] [d/l]