How to shorten a string without slicing through a word while keeping within a character limit in PHP [duplicate]

Question

Possible Duplicate:
How to Truncate a string in PHP to the word closest to a certain number of characters?

How can I shorten a string to a maximum of 140 chars without slicing through a word.

Take the following string:

$string = "This is an example string that contains more than 140 characters. If I use PHPs substring function it will split it in the middle of this word."

Using substr($string, 0, 140) we would get something like this:

This is an example string that contains more than 140 characters. If I use PHPs substring function it will split it in the middle of this wo

Notice it sliced through the word "word".

What I need is to be able to shorten a string while preserving entire words but without going over 140 characters.

I did find the following code but even though it will preserve entire words, it does not guarantee that the entire string does not go over the 140 char limit:

function truncate($text, $length) {
   $length = abs((int)$length);
   if(strlen($text) > $length) {
      $text = preg_replace("/^(.{1,$length})(\s.*|$)/s", '\\1...', $text);
   }
   return($text);
}

Answer 1

If the string is too long, you can first use substr to truncate the string and then a regular expression to remove the last full or partial word:

$s = substr($s, 0, (140 - 3));
$s = preg_replace('/ [^ ]*$/', ' ...', $s);

Note that you have to make the original shorter than 140 bytes because when you add the ... this could increase the length of the string beyond 140 bytes.