替换不在标记内的所有换行实例

Question

I have a body of text with newlines in it, and I would like to replace all instances of newlines that are not inside certain tags with <br />s. The tags are [something][~something], where something could be anything.

Sorry for not including what I have already tried, but I have no idea how to get a regex to match something not inside something else. Is that even possible?

Answer 1

While remembering that you should not parse XML/HTML with a regex and this is an instance of that:

#!/usr/bin/perl
#

$in = "foo
bar
baz[something]else
is
[~something]
Happening
[something]else
is
[~something]here
";
$out = "";

while ($in =~ s/^(.*?)(\[something\].*?\[~something\])//s)
{
  my($before,$during) = ($1,$2);
  $before =~ s/
/<br \/>/g;
  $out .= $before.$during;
}
$in =~ s/
/<br \/>/g;
$out .= $in;
print $out;

Yes, not in your language of choice, but the concept (parsing the data in stages stuff before your tags and stuff inside your tags while deleting the processed data) should be portable.