trim a string.

[zozzen]

Hi i faced a problem about trimming a string.

If I fetch a page, and get a sequence of strings like:
http://www.example.com/cook/french/article_id=001
http://www.example.com/cook/japanese/article_id=002
http://www.example.com/cook/english/article_id=003
http://www.example.com/deepfried/american/article_id=004
http://www.example.com/steam/abc/article_id=005
http://www.example.com/steam/dddd/article_id=006

Only article_id is useful to me and the rest is relevant, is there any function that i can ONLY keep the article_id?

Thanks a lot!

[edited by: dreamcatcher at 1:32 pm (utc) on Feb. 17, 2008]
[edit reason] Use example.com, thanks. [/edit]

[zozzen]

corrected:

....only article_id is useful to me and the rest is irrelevant. sorry for the typo.

[RonPK]

You could either use a combination of substr() [php.net] and strrpos() [php.net], or preg_replace() [php.net] with a regular expression.

[zozzen]

thanks for the hints! Regular expression is very useful.

eregi_replace("http://www.example.com/[a-z]/[a-z]","http://www.example.com",$output);

[edited by: dreamcatcher at 1:33 pm (utc) on Feb. 17, 2008]
[edit reason] Use example.com, thanks. [/edit]

[jatar_k]

if the urls are always in that form you could just split [php.net] it on =

[PHP_Chimp]

Or if you just want to keep the last few numbers but there may be a different splitting character then -

preg_match('%(\d+)$%', $input, $matches);
echo $matches[1];

As this will match any numbers at the end of a string. So as long as the splitting character isnt another number then this will return the last numbers (so long as there is at least 1) from the end of the string.

[dragon master mokuba]

here is a little function i use in some of my coding.

<?php
function lastIndexOf($string,$item) {
$index=strpos(strrev($string),strrev($item));
if ($index)
{
$index=strlen($string)-strlen($item)-$index;
return $index;
}
else {
return -1;
}
}
function processText($txt) {
$length1 = lastIndexOf($txt,"article_id");
$length2 = strrev($txt);
$length3 = substr($length2, 0, -$length1);
$length4 = strrev($length3);
//uncomment the next two lines if you just want the number and change "return $length4" to "return $length6"
//$length5 = explode("=",trim($length4));
//$length6 = $length5[1];
return $length4;
}
?>

and to use it:

$sample = "http://www.example.com/cook/french/article_id=001"; // input string
$sample2 = processText($sample);
echo $sample2;

[zozzen]

Thanks for all inspirations here. s a beginner i'm really exhausted with the fact that the same task can be done by so many different function, but it makes php more interesting to me. Thanks again!