Drupal 7 - access to page content in template.php In Drupal 7 I'm trying to access the body field of a page from template.php. I want to find a keyword in the text and then send subsequent text to a separate variable so that I can format it in page.tpl.php

I can access the node using 
    $vars['node']
but can't find a way of accessing the content part of the node.

I can access the content in page.tpl.php using:
    $node->body[$node->language][0]['value']
but cant use the same or similar syntax in template.php
In page.tpl.php the content of the page is available in $page['content']. It seems that your are mixing two different concepts here: pages, any page on the site (including administration page, taxonomy terms page, and other not directly editable pages) and nodes, editable content. This can be rather confusing as a default Drupal installation provides a page content type. So you end up with page nodes, which are nodes of a the page content type.

The layout of the content of a page displaying a node, is handled in the node.tpl.php template. In this template, the body of the displayed node is available in $content['body'].

If you really need to access a field (handled using the Field API) of the node object ($node) from the page preprocess function in your template.php, you can use:

function THEME_preprocess_page(&amp;$variables) {
    $node =&amp; $variables['node'];
    $value = field_get_items('node', $node, 'FIELDNAME);
}