I am importing allot of product data from an XML file (about 5000 products). When I run the script I can make it work in about 10-12 seconds.

Now, when I add this punctuation function which makes sure each product description ends with a punctuation sign, the code runs until the php 60 seconds loadtime on my server but I'm not getting any errors. I have error reporting turned on. I just get a final error that the script could not load in 60 seconds.

The question is, looking at this function, is it that resource consuming? What can I do to make it faster?

function punctuation($string){
    if(strlen($string) > 5){
        // Get $last_char
        $desired_punctuation = array(".",",","?","!");
        $last_char = substr($string, -1); 
        // Check if $last_char is in the $desired_punctuation array
        if(!in_array($last_char, $desired_punctuation)){ 
        // strip the $mytrim string and get only letters at the end;
            while(!preg_match("/^[a-zA-Z]$/", $last_char)){
                $string = substr($string, 0, -1);
                $last_char = substr($string, -1);
            }
            // add "." to the string
            $string .= '.'; 
        } 
    }
    return $string;
}

If the function is ok, the long runtime must come from something else which I'll have to discover.

I just want your input on this part.