http://www.perlmonks.org?node_id=907330


in reply to Regexp - match if not between [ ]

Using Text::CSV would probably be better. However, this regex approach, while more verbose, is perhaps more maintainable. Needs 5.10+ Special Backtracking Control Verbs. (I've made a guess at the proper regex for a A423.23 thingy.)

>perl -wMstrict -le "my $s = 'The fox did it[ at 12.23 ] well, Cf. 23 A423.23. The ' . 'swallow was even better'; print qq{''$s''}; ;; my $parens = qr{ \[ [^]]* \] }xms; my $cf = qr{ (?i) cf \. }xms; my $ref = qr{ [[:alpha:]]+ \d+ (?: \. \d+)+ }xms; my $splitter = qr{ (?: $parens | $cf | $ref) (*SKIP)(*FAIL) | \. }xms; ;; my @ra = split $splitter, $s; print qq{'$_'} for @ra; " ''The fox did it[ at 12.23 ] well, Cf. 23 A423.23. The swallow was eve +n better'' 'The fox did it[ at 12.23 ] well, Cf. 23 A423.23' ' The swallow was even better'