Using str_replace so that it only acts on the first match?

Question

I want a version of str_replace() that only replaces the first occurrence of $search in the $subject. Is there an easy solution to thi

Answer 1

=> CODE WAS REVISED, so consider some comments too old

And thanks everyone on helping me to improve that

Any BUG, please communicate me; I'll fix that up right after

So, lets go for:

Replacing the first 'o' to 'ea' for example:

$s='I love you';
$s=str_replace_first('o','ea',$s);
echo $s;

//output: I leave you

The function:

function str_replace_first($a,$b,$s)
         {
         $w=strpos($s,$a);
         if($w===false)return $s;
         return substr($s,0,$w).$b.substr($s,$w+strlen($a));
         }