[Resolved] Regular expression help...

The_Chancer

I am trying to remove part of a string - but the exact part may well vary...

From print_r(parse_url($_SERVER['REQUEST_URI']))

I get
(
[path] => /
[query] => pg=products&what=neworder&lookup=1&view=false&add=3&supplier=Bose&company=all&category=all&search=&offset=0
)

What I need to do is remove the add=x part - however this can be anything from 1 number upwards... however it will always be followed by the & for the next part in the query.

As it isn't static I can't really use the str_replace - so regular expressions will be able to do the trick...

Any ideas ?

Cheers,

bubblenut

<?php
$_SERVER['REQUEST_URI']['query']=preg_replace('/&add=\\d+&/','&',$_SERVER['REQUEST_URI']['query']);
?>

Looks like my regex investigating has payed off (even if notmuch for my own work 🙁 )
Bubble
[edit]
Damn backslashes !!

The_Chancer

Cheers for that.... looks like I was on sorta the right track...

I had preg_replace("/&add=[a-z][A-Z][0-9]/","",$_SERVER['REQUEST_URI']['query'])

But is only gives /

Very strange....

What does the "d" stand for in yours ?

bubblenut

any digit (same as [0-9]) and then the + after means we want 'at least one'.
Bubble

The_Chancer

It does work...

But I had to change it a little to;

$stuff=parse_url($_SERVER['REQUEST_URI']);
$str=preg_replace('/&add=\d+&/','&',$stuff['query']);

If I was to include a-z A-Z 0-9 as well - is there a short code for this, or would I use
[a-z][A-Z] etc ?

Cheers,

bubblenut

There probably is a shortcut but I'd just put it in a character class. However, note that you must put them all in the same character class. The way you had done it you were defining three seperate character classes. [a-z][A-Z][0-9] would match on three characters, the first would have to be a lower case letter the second an upper case letter and the third a digit. You would need [a-zA-Z0-9] or just [A-z0-9].
HTH
Bubble

The_Chancer

Ahh - you learn something new every day..

Many thanks,

Weedpacket

Originally posted by The Chancer
Ahh - you learn something new every day..

Many thanks,

<thread now resolved>

Just as an aside; [A-z] matches the characters `_^][ as well, if that might be a problem.

You could write [[:alnum:]] but that's hardly shorter than [A-Za-z0-9].

The_Chancer

Would the [[:alnum:]] also include `_^{][ as it is referring to a userdefined field - I am just wondering which chars I should let through...

<and guess what I watched last night ?>

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Fun, fun, fun, in the sun, sun, sun.

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Robot Wars don't know how good they have got it....}

Weedpacket

Originally posted by The Chancer
Would the [[:alnum:]] also include `^][ as it is referring to a userdefined field - I am just wondering which chars I should let through...

No, [[:alnum:]] matches a-z, A-Z, and 0-9; it matches the same characters as [man]ctype_alnum[/man] (and there are similar classes for the other ctype* functions).

Which characters you want to allow through depends of course on what the data is for: even if it would be safe for it to contain [, say, it might be that disallowing it will be helpful in cases where the user intended to strike p but didn't notice the mistake.

bubblenut

Originally posted by Weedpacket
Just as an aside; [A-z] matches the characters `_^{][ as well, if that might be a problem.}

Oh, cool! I had my suspicions it was done on ascii codes (adn that's why it goes from A-z rather a-Z).
Thanks
Bubble

jenni

Just to clarify...
[A-Za-z0-9] will only allow alpha-numeric characters, but
[A-z] will allow `_^{][

Is that right?}

bubblenut

Yes, have alook at this ASCII Table , you will notice that between 05A (Z) and 061(a) are those characters, this is why they are contained within [A-z].
HTH
Bubble

jenni

Crazy...

Luckily the ultimate regex tutorial (http://phpbuilder.com/columns/dario19990616.php3 ) that got me started, had it the correct way. It is a good thing to know for the future. Thanks for the tip.

bubblenut

It may be sacriligous to say so but there are some even better regex tutorials out there going in more detail (mainley with pcre regex) Here 's a good one for example. Explaines about backreferencing, greed and lookaheads.
Also, if you've got some time free, have a look here , admitadly a much better explained tutorial, just a little long.
If you're looking for a book on them everyone seems to recomend O'Reilly: Mastering Regular Expressions . My copy's just come through today so I haven't had much of a chance to read through it yet but it looks pretty damn comprehensive. Too much information?
HTH
Bubble

jenni

Thanks for the info. I bookmarked the sites. The reason I prefer the other tutorial is that I was a designer, not a coder when I got into this. Most stuff I found assumed that you had a certain amount of prior experience...I didn't even know it was called regex until I found this forum. 🙂