Modifies WordPress excerpt via functions.php

modify_wp_excerpt.php

////////////////////
// CUSTOM EXCERPT //
////////////////////

function custom_excerpt_length( $length ) {
    return 20;
}
add_filter( 'excerpt_length', 'custom_excerpt_length', 999 );

function custom_excerpt_more( $more ) {
    return sprintf( '... <a class="bw-read-more" href="%1$s">%2$s</a>',
        get_permalink( get_the_ID() ),
        __( 'READ MORE &raquo;', 'textdomain' )
    );
}
add_filter( 'excerpt_more', 'custom_excerpt_more' );