[PHP] Finding a word in a string

I'm getting really annoyed because I've been trying to do this for the past hour, and it certainly can't be that hard. I'm trying to find a word in a string, and replace it just once. So for instance;

"Hello, this is my string and this is the {word} I will be replacing. I won't replace this {word} because it should only work once per message."

I've tried strpos, strstr, eregi, preg, and each and every time it, for some reason, cannot find the word in the string. I'm stuck so if anyone can help me I'll love you.

Sorry misunderstood you.

php code

function str_replace_once($needle , $replace , $haystack){ // Looks for the first occurence of $needle in $haystack // and replaces it with $replace. $pos = strpos($haystack, $needle); if ($pos === false) { // Nothing found return $haystack; } return substr_replace($haystack, $replace, $pos, strlen($needle)); }

ereg_replace() uses POSIX-compatible regular expressions and preg_replace() uses Perl-compatible ones. preg_replace() is often faster and the manual recommends you use it exclusively over ereg_replace().

For questions like this, it's often easier and faster to just go to php.net/<function name here>, for example: php.net/ereg_replace.