in reply to Regex: Identifying comments
Here is another approach:
#! perl use strict; use warnings; my @selects = ("select 'text' from foo --This is a comment", "select '--Not a valid comment' from foo --But t +his is", "select '--This is not a valid comment' from foo", "select '--Not this' + '--either' from foo"); for my $select (@selects) { my ($comment) = $select =~ / ( -- [^']+ ) $ /x; print $comment, "\n" if $comment; }
Output:
--This is a comment --But this is
Update: The above code does not handle single quotes in comments. The following is one way to do this (indebted to choroba’s solution, above):
#! perl use strict; use warnings; my @selects = ("select 'text' from foo --This is a comment", "select '--Not a valid comment' from foo --But t +his is", "select '--This is not a valid comment' from foo", "select '--Not this' + '--either' from foo", "select stuff from that -- a 'useful comment' goes here +?", "select 'qaws' + make from \"a\" -- comment with 'a' qu +ote", "select 'a' from 'b' with 'c' -- comment with 'a --' co +mment"); for my $select (@selects) { my $stripped = $select =~ s/ ( ' .*? ' ) /'_' x length $1/egrx; if ($stripped =~ /--/) { my $i = length($select) - (index reverse($stripped), '--') - 2 +; print substr($select, $i), "\n"; } }
Output:
--This is a comment --But this is -- a 'useful comment' goes here? -- comment with 'a' quote -- comment with 'a --' comment
Hope that helps,
Athanasius <°(((>< contra mundum
|
---|
Replies are listed 'Best First'. | |
---|---|
Re^2: Regex: Identifying comments
by RichardK (Parson) on Aug 29, 2012 at 15:03 UTC | |
by zuma53 (Beadle) on Aug 29, 2012 at 15:49 UTC | |
by choroba (Cardinal) on Aug 29, 2012 at 16:02 UTC |
In Section
Seekers of Perl Wisdom