Excerpt if there is no more tag? REVISTED

you won’t see the <!--more--> on the screen as it is a html comment.

do the var_dump or echo $post->post_content and look into the html in the browser – and it should be there.

(it is at least in my local setup)

simple test line for index.php within the post div:
<?php if( strpos($post->post_content, '<!--more-->') >= 1 ) echo 'we have a more tag!'; ?>

Just because this took me hours to sort out – I just posted my solution to this to another thread about custom excerpt lengths because I was having trouble getting those to show (resolved, http://wordpress.org/support/topic/custom-excerpt-length-doesnt-work-anymore ).

My fix in the end was Instead of using the_excerpt if there isn’t a more tag, I’m doing a custom function to get a content at an arbitrary length.

I’m using a child theme of twenty eleven, hence the $content .= twentyeleven_continue_reading_link(); at the end.

in my showcase.php

// Set $more to 0 in order to only get the first part of the post.
						global $more;
						$more = 0;

						if ( has_post_format()) {
                            get_template_part( 'content', get_post_format() );
                        } else {
                            get_template_part( 'content', 'index' );
						}

In my content-index.php

<?php if (has_more()) {
		        the_content( __( 'Continue reading <span class="meta-nav">→</span>', 'twentyeleven' ) );
		    } else {
                $my_content = limit_content();
                //$my_content = apply_filters('the_content', $my_content);
                //$my_content = str_replace(']]>', ']]>', $my_content);
                echo $my_content;
            }?>

in the functions.php

//more tag detection
//http://wordpress.org/support/topic/check-if-post-has-more
function has_more()
{
 global $post;
 if ( empty( $post ) ) return;

    if ($pos=strpos($post->post_content, '<!--more-->')) {
        return true;
    } else {
        return false;
    }
}

function more_posistion()
{
    if ($pos=strpos($post->post_content, '<!--more-->')) {
        return $pos;
    }
}

//limit content length
//http://www.fusedthought.com/archives/wordpress-custom-content-length-code-snippet
function limit_content($content_length = 150, $allowtags = true, $allowedtags = '') {
	global $post;
	$content = $post->post_content;
	$content = apply_filters('the_content', $content);
	if (!$allowtags){
		$allowedtags .= '<style>';
		$content = strip_tags($content, $allowedtags);
	}
	$content = str_replace(']]>', ']]>', $content);
	$wordarray = explode(' ', $content, $content_length + 1);
	if(count($wordarray) > $content_length) :
		array_pop($wordarray);
		//array_push($wordarray, '...');
		$content = implode(' ', $wordarray);
		$content .= "</p>";
		$content .= twentyeleven_continue_reading_link();
	endif;

	echo $content;
}

other relevant pages:
http://codex.wordpress.org/Customizing_the_Read_More (“Displaying a “more…” link without a <–more–> tag”)

Actually… even better…

global $more;
 $more = 0;
$format = get_post_format( $post_id );

if ( ! $format ) {
     get_template_part( 'content', 'index' );
} else {
     get_template_part( 'content', get_post_format() );
}