php string searching

danbhala

I'd like search a string for a link

for example, in the string there is the following link and image that i'd like to hunt down

<a href=http://mysite.com/page.php><img src="http://mysite.com/img.gif&quot; /></a>

i'd like to search the entire string for that specific url. then would like to get the location of the image that is inside the <a> tag

could anyone help?!

basically i want to find the url of the image that lies within a certain link

Evil Phil

Dunno php very well (yet!) but this sounds like a job for regular expressions*.



*Note: regular expressions may not wear a cloak.

democrates

I think a full html tokenizer would be overkill, and I'm guessing if you can't do this then regexes might be a bit of a stretch, but something you should look at when you get time, they're priceless.

I'd start searching for the position of known character sequences eg "gif" and working backwards to the preceding "http". Play around with the values for offsets, echo the variables if it's not working, and bit by bit build up your program.

All the functions you need to search strings forwards and backwards are in the usual place :
http://www.php.net/manual/en/ref.strings.php
In particular
http://www.php.net/manual/en/function.strpos.php
http://www.php.net/manual/en/function.strrpos.php

As you're dealing with lists of links this might be handy
http://www.php.net/manual/en/ref.array.php

GoneShootin

1 - GET pos1 of '<img'

THEN

2 - GET pos2 of '/>' with

http://ie2.php.net/manual/en/function.stripos.php

THEN

3 - GET string from pos1 to pos2 (the entire img tag) with

http://ie.php.net/substr

THEN

REPEAT 1 and 2 for <img src="http://mysite.com/img.gif&quot; /> using

4 - pos3 as ' " ' AND

5 - pos4 as ' " /> '

THEN

REPEAT 3 from pos3 plus 1 (move counter from " to h) AND pos 4 minus 4 (move counter from " /> to f)

OR

http://ie2.php.net/manual/en/function.preg-match-all.php


What do you expect, its late on a Friday!

skiff79

Regular expressions is best idea, no matter what programming language is about.