[SOLVED] Regex on URL

[kevingarnett2000]

Hi,

 

Lets see the following URL:

 

http://somewebsite.com?var1=value1&var2=value2&var3=value3&

 

I need to replace certein parameters in this url

 

so i did something like:

 

$url = "http://somewebsite.com?var1=value1&var2=value2&var3=value3&";

 

$pattern = "/var1=.*&/";

$replace = "var1=someothervalue&";

 

echo preg_replace($pattern, $replace, $url);

 

However it is not producing the correct result, it echos:

 

"http://somewebsite.com?var1=someothervalue&"

 

My question is: How do I go about writing the regular expression?

 

Thank you,

Kevin

[MadTechie]

what about this

 

<?php
$subject= "http://somewebsite.com?var1=value1&var2=value2&var3=value3&";
$Var = "var1";
$Value = "NewValue"
$result = preg_replace('/(?:$Var=)(\w+)/im', '$1=$Value', $subject);
echo $result;
?>

[effigy]

The * is greedy, thus gobbling everything up to the last &. You can fix this by making it ungreedy: *?. Alternatively, don't bother matching the variable name only to put it back--use a lookaround:

 

/(?<=var1=)[^&]*/

[kevingarnett2000]

That was helpful, thank you very much.

 

Your regards,

Kevin