preg_replace and regular expressions

timbr8ks

I have a long block of text ($oldText), and I need to insert a second block of text right after the first paragraph. Paragraphs are divided by <br /><br />, except there's a line break between them. The goal is to insert $newText right after the first two line breaks.

So, I wanted to do something like this:

$pattern = '<br />\n<br />';
$completeText = preg_replace('$pattern', '$pattern.$newText', '$oldText', 1);
echo $completeText;

But, it didn't work, probably because I'm struggling with regular expressions.

Can anyone help me with this one?

Thanks.

alimadzi

Use double quotes instead of single quotes. Variables inside single quotes are not interpolated (replaced by their values).

xblue

1) PCRE need delimiters (some special characters that enclose the pattern). In your pattern, the < and > would be treated as delimiter instead of being part of the pattern. Use e.g. $pattern = '#<br />\n<br />#';

2) Are you sure that the line breaks will always be *nix style? If not, you could e.g. use [\r\n]+ to match \n, \r and \r\n (it would also match a sequence of linebreaks, but usually this shouldn't hurt I think).

3) If you intend to reuse what was matched in the replacement argument, use a backreference, like $0 for the complete match.