use strict;
my $str = 'fruit apple
some other config line
############
fruit banana
fruit cherry
other config 1
other config';
my $regex = qr/^((?!\bfruit\b).)* # nothing with "fruit" before
( # then, either:
# 1. fruit apple, followed by things that are not "fruit", followed by fruit banana, non-fruits, and then fruit cherry, or vice versa
\bfruit\b\ apple((?!\bfruit\b).)*(\bfruit\b\ banana((?!\bfruit\b).)*fruit\ cherry|fruit\ cherry((?!\bfruit\b).)*fruit\ banana)
|
# 2. Same with banana at the beginning
fruit\ banana((?!\\bfruit\b).)*(fruit\ apple((?!\bfruit\b).)*fruit\ cherry|fruit\ cherry((?!\bfruit\b).)*fruit\ apple)
|
# 3. And with cherry
fruit\ cherry((?!\bfruit\b).)*(fruit\ apple((?!\bfruit\b).)*fruit\ banana|fruit\ banana((?!\bfruit\b).)*fruit\ apple)
)
((?!\bfruit\b).)*$ # no more fruit/sxp;
if ( $str =~ /$regex/g ) {
print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n";
# print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n";
# print "Capture Group 2 is $2 ... and so on\n";
}
# ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p'
# Named capture groups can be called via $+{name}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html