Ommitting a specific pattern from a regex statement - php

Question

I've spent the last couple of days trying to figure out how to resolve this particular issue and posting on SO, but no dice so far. I think this is probably easier than I've been making it to be, but I need some help;
Here is a pretty basic regex statement that linkifies pretty much any link. It's not the only regex pattern I have, so I've included a piece that skips over the link if it includes the specific pattern "img.youtube.com/vi/" It works great;
$message = preg_replace("#(((f|ht)tp(s)?://)?!(img.youtube.com/vi/)[-a-zA-Z?-??-?()0-9#:%_+.~\#?&;//=,])+#i", "<a href=$1 target='_blank'><b>$1</b></a>", $message);
I do not want this to linkify any url with .jpeg, jpg, gif, or any popular image format, I have another expression that will embed those kinds of links (and it works fine, too). So, I need to find a way to get this expression to reject those kinds of links.
I've gotten advice on negative lookarounds, matching to specific strings, but none of them seem to work so far. I need to find a way to get this regex to ignore any URL that ends with .jpeg and so forth;
So, the regex statement above already has an example of a string that disqualifies certain URLs - ?!(img.youtube.com/vi/). This seems like that's all I need to do, but where do I put it and how does it look? The + symbol in the statement makes it so that the regex will scrutinize the string all the way to the end of it, using the matching characters of [-a-zA-Z?-??-?()0-9#:%_+.~#?&;//=,]. So, this matching string should probably be put somewhere before the + symbol. Does it go in "?!(img.youtube.com/vi/)" ? In my mind, it should probably look like this;
$message = preg_replace("#(((f|ht)tp(s)?://)?!(img.youtube.com/vi/|/^\.jpeg$/|/^\.jpg$/|/^\gif$/)[-a-zA-Z?-??-?()0-9#:%_+.~\#?&;//=,])+#i",
"<a href=$1 target='_blank'><b>$1</b></a>", $message);
Any help is appreciated.

Answer 1

I answer and also clean up your regexp
(?i)((?:f|ht)tps?://((?!img|jpe?g|gif|png|bmp))(?:([-a-z0-9()#:%_+.~#?&;/=,])(?2))+(?!(?3)))
Now the img etc you don't want is in the neg lookahead and you can add a things you don't like.
$good="http://www.google.com/";
$bad="http://img.google.com/";
$r="#(?i)((?:f|ht)tps?://((?!img|jpe?g|gif|png|bmp))(?:([-a-z0-9()#:%_+.~\#?&;/=,])(?2))+(?!(?3)))#";
$rep="<a href=$1 target='_blank'><b>$1</b></a>";
echo preg_replace($r,$rep,$good);
echo preg_replace($r,$rep,$bad);
You can try here http://ideone.com/419yfm

Answer 2

Just remove this part of the regex:
img|
<?php
$good="http://www.google.com/";
$bad="http://img.google.com/";
$r="#(?i)((?:f|ht)tps?://((?!jpe?g|gif|png|bmp))(?:([-a-z0-9()#:%_+.~\#?&;/=,])(?2))+(?!(?3)))#";
$rep="<a href=$1 target='_blank'><b>$1</b></a>";
echo preg_replace($r,$rep,$good); echo "\n";
echo preg_replace($r,$rep,$bad);
?>
DEMO