preg_replace() syntax off

[justride]

I'm very imcompetent with this regexp stuff.

anyways I am using the function preg_replace to replace backslashes with forward slashes for all html links. This is what I have

return preg_replace('/<a[^>]*>/','whatgoeshere',$str);

The function spots the links in the str, but I dont know the syntax to use to replace only the backslashes with forward slashes. any idea???

THANKS!

 

[DRJ478]

I just had a very similar thread: thread434-966516
Read there for the detailed explanation of the expression. There is very little difference, which I will explain.

<?
$text = '<A name="whatever" class="myclass" href = "here.com\test.html" id="whatever">';
$pattern = '/(<a[^>]*href\s*=\s*[\'"])([^\'"]*)([\'"][^>]*>)/ie';
$newText = preg_replace($pattern,"'\\1'.str_replace(chr(92),'/','\\2').'\\3'",$text);
?>

The regex is basically the same, just that three parts are captured with subpatterns. They are re-assembled because we need the full anchor tag.
The pattern also has the added modifier e which means that in preg_replace the second parameter (which is the replacement specifier) will be interpreted as PHP code. That way we are able to reassemble part1 + str_replace() on part2 where backslash is converted to forward slash + part3.
Be careful with the final result and see if a stripslashes() is necessary.

 

[justride]

That appeared to work except it added a slash before the qoutes in the start and end of the url

 

[DRJ478]

Be careful with the final result and see if a stripslashes() is necessary.

This is installation dependent (magic quotes). The only thing to add is the stripslashes($newText);

 

[justride]

the final results look like this
<a href =\"

http://...\"

>

is it possible to eliminate the baclskashes before the qoutes? no clue why it puts these in. I could do a string replace I guess. It be nicer to do it in the pregreplace so its done right. thanks though!

 

[DRJ478]

Yes, it is possible to eliminate the escaped doublequotes. The function for that is stripslashes().

$newText = stripslashes(preg_replace($pattern,"'\\1'.str_replace(chr(92),'/','\\2').'\\3'",$text));

 

[justride]

but what about slashes that are needed? we dont want to strup all slashes

 

[DRJ478]

The function stripslashes() removes backslashes not forward slashes. Since we just replaced all backslashes with forward slashes there aren't any that would be wrongly removed.

 

[justride]

Well there are some instances where I dont want to strip the back slashes. I did a replace on all \" instead of \.

Anyways, this script worked well. I came across a file where not all the links had there slashes reversed. I can post the file when I get to work tomorrow, but the example was something like
<a href = "...e\7..."> and the slash was not switched. I didnt have time to go through all the files but all appeared ok except this one. I'll post tomrorow, maybe there is a bug in the script?

Thanks
Chris

 

[justride]

Hi,

I have numerous html files, here is an example of where a slash wasnt changed.

<a
href="PIWG's_774_Dockside_Harmonic_Database\774_Dockside_Harmonic_Database_2_Nov_04.xls">PIWG’s
SSN774 Dockside Harmonic Database<span style="mso-spacerun: yes">   </span></a>

the slsh between the e and the 7 remained. However I added other slashes in that link elsewhere and they were switched.

Any ideas?

Here is the file:

http://www.ctremblay.com/ASC/774_Dockside_index.htm

Thanks!

 

[DRJ478]

The slash is not replaced because there is a single quote inside the URL. As far as I am concerned I consider the URL faulty. Quotes, single or double, have no place in filenames.

I'll try to devise a regex that will process the above URL. Check back.

 

[justride]

Ahhh, Nice find.

I agree with you completely! This is a wacky design; originally all the file names had spaces etc... Now I'm just cleaning up the links so this whole thing works in Linux.

Don’t worry about creating a regex, now that I know the problem, I can fix it in the very few places that I have seen and just go from there. It’s no biggie. This whole design will be scraped soon anyways as I am going to redo the whole thing using php and mysql.

Thanks!

 

[DRJ478]

Here's the result. Let me know if you want an explanation.

<?
$text = '<a href="PIWG\'s_774_Dockside_Harmonic_Database\774_Dockside_Harmonic_Database_2_Nov_04.xls" class="whatever">Link text<span style="mso-spacerun: yes">';
$pattern = '/(<a[^>]*href\s*=\s*)(?:"(.*?)"|\'(.*?)\')([^>]*>)/ie';
$newText = preg_replace($pattern,"'\\1\"'.str_replace(chr(92),'/','\\2').'\"\\3\\4'",$text);
print(stripslashes($newText));
?>