php trim a string

Question

I'm trying to build a function to trim a string is it's too long per my specifications.

Here's what I have:

function trim_me($s,$max) 
{
    if (strlen($s) > $max) 
    {
        $s = substr($s, 0, $max - 3) . '...';
    }
    return $s;
}

The above will trim a string if it's longer than the $max and will add a continuation...

I want to expand that function to handle multiple words. Currently it does what it does, but if I have a string say: How are you today? which is 18 characters long. If I run trim_me($s,10) it will show as How are yo..., which is not aesthetically pleasing. How can I make it so it adds a ... after the whole word. Say if I run trim_me($s,10) I want it to display How are you... adding the continuation AFTER the word. Any ideas?

I pretty much don't want to add a continuation in the middle of a word. But if the string has only one word, then the continuation can break the word then only.

Answer 1

function trim_me($s,$max) {
    if( strlen($s) <= $max) return $s;
    return substr($s,0,strrpos($s," ",$max-3))."...";
}

strrpos is the function that does the magic.

Answer 2

So, here's what you want:

<?php
// Original PHP code by Chirp Internet: www.chirp.com.au 
// Please acknowledge use of this code by including this header.
function myTruncate($string, $limit, $break=".", $pad="...") { 
    // is $break present between $limit and the end of the string? 
    if(false !== ($breakpoint = strpos($string, $break, $limit))) { 
        if($breakpoint < strlen($string) - 1) { 
            $string = substr($string, 0, $breakpoint) . $pad; 
        } 
    } 
    return $string;
}
?>

Also, you can read more at http://www.the-art-of-web.com/php/truncate/

Answer 3

I've named the function str_trunc. You can specify strict being TRUE, in which case it will only allow a string of the maximum size and no more, otherwise it will search for the shortest string fitting in the word it was about to finish.

var_dump(str_trunc('How are you today?', 10)); // string(10) "How are..."
var_dump(str_trunc('How are you today? ', 10, FALSE)); // string(14) "How are you..."

// Returns a trunctated version of $str up to $max chars, excluding $trunc.
// $strict = FALSE will allow longer strings to fit the last word.
function str_trunc($str, $max, $strict = TRUE, $trunc = '...') {
    if ( strlen($str) <= $max ) {
        return $str;
    } else {
        if ($strict) {
            return substr( $str, 0, strrposlimit($str, ' ', 0, $max + 1) ) . $trunc;
        } else {
            return substr( $str, 0, strpos($str, ' ', $max) ) . $trunc;
        }
    }
}

// Works like strrpos, but allows a limit
function strrposlimit($haystack, $needle, $offset = 0, $limit = NULL) {
    if ($limit === NULL) {
        return strrpos($haystack, $needle, $offset);
    } else {
        $search = substr($haystack, $offset, $limit);
        return strrpos($search, $needle, 0);
    }
}

Answer 4

It's actually somehow simple and I add this answer because the suggested duplicate does not match your needs (but it does give some pointers).

What you want is to cut a string a maximum length but preserve the last word. So you need to find out the position where to cut the string (and if it's actually necessary to cut it at all).

As getting the length (strlen) and cutting a string (substr) is not your problem (you already make use of it), the problem to solve is how to obtain the position of the last word that is within the limit.

This involves to analyze the string and find out about the offsets of each word. String processing can be done with regular expressions. While writing this, it reminds me on some actually more similar question where this has been already solved:

• Extract a fixed number of chars from an array, just full words (with regex)
• How to get first x chars from a string, without cutting off the last word? (with wordwrap)

It does exactly this: Obtaining the "full words" string by using a regular expression. The only difference is, that it removes the last word (instead of extending it). As you want to extend the last word instead, this needs a different regular expression pattern.

In a regular expression \b matches a word-boundary. That is before or after a word. You now want to pick at least $length characters until the next word boundary.

As this could contain spaces before the next word, you might want to trim the result to remove these spaces at the end.

You could extend your function like the following then with the regular expression pattern (preg_replace) and the trim:

/**
 * Cut a string at length while preserving the last word.
 * 
 * @param string $str
 * @param int $length
 * @param string $suffix (optional)
 */
function trim_word($str, $length, $suffix = '...') 
{
    $len = strlen($str);

    if ($len < $length) return $str;

    $pattern = sprintf('/^(.{%d,}?)\b.*$/', $length);
    $str = preg_replace($pattern, '$1', $str);
    $str = trim($str);
    $str .= $suffix;

    return $str;
}

Usage:

$str = 'How are you today?';
echo trim_word($str, 10); # How are you...

You can further on extend this by reducing the minimum length in the pattern by the length of the suffix (as it's somehow suggested in your question, however the results you gave in your question did not match with your code).

I hope this is helpful. Also please use the search function on this site, it's not perfect but many gems are hidden in existing questions for alternative approaches.