limiting excerpt

//Function.php

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;
}

Now, in every place where you use the_excerpt() or the_content() in your loop, use excerpt($limit) or content($limit).

For example if you want to limit your excerpt length to 30 words use echo excerpt(30) and for content.