trim.php

<?php

function wp_trim_words( $text, $num_words = 55, $more = null ) {
        if ( null === $more )
                $more = __( '&hellip;' );
        $original_text = $text;
        $text = wp_strip_all_tags( $text );
        /* translators: If your word count is based on single characters (East Asian characters),
           enter 'characters'. Otherwise, enter 'words'. Do not translate into your own language. */
        if ( 'characters' == _x( 'words', 'word count: words or characters?' ) && preg_match( '/^utf\-?8$/i', get_option( 'blog_charset' ) ) ) {
                $text = trim( preg_replace( "/[\n\r\t ]+/", ' ', $text ), ' ' );
                preg_match_all( '/./u', $text, $words_array );
                $words_array = array_slice( $words_array[0], 0, $num_words + 1 );
                $sep = '';
        } else {
                $words_array = preg_split( "/[\n\r\t ]+/", $text, $num_words + 1, PREG_SPLIT_NO_EMPTY );
                $sep = ' ';
        }
        if ( count( $words_array ) > $num_words ) {
                array_pop( $words_array );
                $text = implode( $sep, $words_array );
                $text = $text . $more;
        } else {
                $text = implode( $sep, $words_array );
        }
        return apply_filters( 'wp_trim_words', $text, $num_words, $more, $original_text );
}