fork download
copy 
  1. use v5.12;
  2.  
  3.  
  4. my $re = qr/^
  5.   (?=
  6.     (
  7.       (?:
  8.           (?= (X.*\n | .(?-1). ) X)
  9.           .*\n # go to next line
  10.       ){2}
  11.       .* # include next line in $1
  12.     )
  13.   )
  14. /mx;
  15.  
  16. my $no = <<'STR';
  17. ....X...
  18. .X..X...
  19. .X......
  20. STR
  21.  
  22. my @m = $no =~ $re;
  23. say @m ? "matched": "no match";
  24.  
  25.  
Success #stdin #stdout 0s 3608KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
matched
https://ideone.com/UxVxJ9
language:
Perl (perl 5.28.1)
created:
10 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!