Remove x characters from the middle of a string.

[Markus]

I'm stuck on a little bit of logic.

Imagine, if a string's length, l, exceeds some specified maximum length, m. How could you then remove the correct amount of characters from the center of the string (replace with ellipsis: ...) so that it is less than or equal to the maximum length.

m = 20
string = averylongstring over20chars

would become: averylongs...ve r20chars

I'm befuddled on this one.

[code green]

I wrote this 2-3 years ago that did similar to what you are asking (I think)
Not making any great claims on how it works but maybe will help you.
I used it as part of a search engine.
I think BLOCK is a constant int.
highlight() is another function that colours matching terms red

function parseText($text,$findme)
{
    $textArray = preg_split ('/ /', $text );
    $words = sizeof($textArray);
    
    $side = (int)(BLOCK/2);
    $line = '';

    for($key=0;$key<$words;$key++)
    {
        if($key<$side)
            $start = 0;
        else
            $start = $key-$side;
        if(($start+BLOCK)>$words)
            $start = $words-BLOCK;

        $pos = stripos($textArray[$key], $findme);
        if ($pos !== false)
        {
            $chunk =  array_slice ($textArray,$start,BLOCK);
            $chunk = implode($chunk,' ');

            //Add Ellipses
            if($start>0)
                $line .= '.....';
           if($words>($start+BLOCK))
                $chunk .= '.....';
            $line .= $chunk;
            $line .= '<br>';
        }
    }//for
    if($line!='')
        $display = highlight($line,$findme);
    //No matches found so just truncate text
    else
    {
        $chunk =  array_slice ($textArray,0,BLOCK);
        $display = implode($chunk,' ');
        $display .= '.....';
    }
    return $display;
}