Multiple excerpt lengths in wordpress

How about...

function excerpt($limit) {
      $excerpt = explode(' ', get_the_excerpt(), $limit);

      if (count($excerpt) >= $limit) {
          array_pop($excerpt);
          $excerpt = implode(" ", $excerpt) . '...';
      } else {
          $excerpt = implode(" ", $excerpt);
      }

      $excerpt = preg_replace('`\[[^\]]*\]`', '', $excerpt);

      return $excerpt;
}

function content($limit) {
    $content = explode(' ', get_the_content(), $limit);

    if (count($content) >= $limit) {
        array_pop($content);
        $content = implode(" ", $content) . '...';
    } else {
        $content = implode(" ", $content);
    }

    $content = preg_replace('/\[.+\]/','', $content);
    $content = apply_filters('the_content', $content); 
    $content = str_replace(']]>', ']]>', $content);

    return $content;
}

then in your template code you just use..

<?php echo excerpt(25); ?>

from: http://bavotasan.com/tutorials/limiting-the-number-of-words-in-your-excerpt-or-content-in-wordpress/

I was looking for this feature as well and most of the functions here are good and flexible. For my own case I was looking for a solution that shows a different excerpt length only on specific pages. I'm using this:

function custom_excerpt_length( $length ) {
    return (is_front_page()) ? 15 : 25;
}
add_filter( 'excerpt_length', 'custom_excerpt_length', 999 );

Paste this code inside the themes functions.php file.

As for now, you can upgrade Marty's reply:

function excerpt($limit) {
    return wp_trim_words(get_the_excerpt(), $limit);
}

You can also define custom 'read more' link this way:

function custom_read_more() {
    return '... <a class="read-more" href="'.get_permalink(get_the_ID()).'">more&nbsp;&raquo;</a>';
}
function excerpt($limit) {
    return wp_trim_words(get_the_excerpt(), $limit, custom_read_more());
}

This is what I came up with.

Add this to your functions.php

class Excerpt {

  // Default length (by WordPress)
  public static $length = 55;

  // So you can call: my_excerpt('short');
  public static $types = array(
      'short' => 25,
      'regular' => 55,
      'long' => 100
    );

  /**
   * Sets the length for the excerpt,
   * then it adds the WP filter
   * And automatically calls the_excerpt();
   *
   * @param string $new_length 
   * @return void
   * @author Baylor Rae'
   */
  public static function length($new_length = 55) {
    Excerpt::$length = $new_length;

    add_filter('excerpt_length', 'Excerpt::new_length');

    Excerpt::output();
  }

  // Tells WP the new length
  public static function new_length() {
    if( isset(Excerpt::$types[Excerpt::$length]) )
      return Excerpt::$types[Excerpt::$length];
    else
      return Excerpt::$length;
  }

  // Echoes out the excerpt
  public static function output() {
    the_excerpt();
  }

}

// An alias to the class
function my_excerpt($length = 55) {
  Excerpt::length($length);
}

It can be used like this.

my_excerpt('short'); // calls the defined short excerpt length

my_excerpt(40); // 40 chars

This is the easiest way that I know of to add filters, that are callable from one function.