how to write the output of this function in field 'tags' on post-edit

I would like to write the tags, titles, and content the same output, just missing it so I finish something I’m doing 🙂

hello joey, thanks for answering here too, you have helped me.
Sorry not have been clear.
I have a function, and want to write the output of it in normal wordpress fields, title, tags, content, the three fields that write when we create a new post, I want to fill them with the output of a function I have, it is:

function gen_num()
{
  global $post;
  $mixnames = get_post_meta( $post->ID, 'fieldnames', true );

  if ( '' == $mixnames ) {
    $input = array("Neo", "Morpheus", "Trinity", "Cypher", "Tank");
    $rand_keys = array_rand($input, 2);
    $mixnames = $input[$rand_keys[1]];
    update_post_meta( $post->ID, 'fieldnames', $mixnames );
  }
  // DISPLAYS THE OUTCOME
  print $mixnames;
}

I enter it in the post on the_content field, and I also want to enter tags in the field (meta tag posts), and title, how do? I’ve tried to start finding something in wordpress structure that suggests it is on the meta tag field, but I see nothing! I want to fill that output in wordpress fields in post-edit the dashboard, I want to see the values ​​in the field tags, title, and body of the post. You may consider a completely different approach. Use an action like ‘wp_insert_post_data’ to enter your content in normal contents of posts, shortly before being saved to the DB. because the values ​​that this function inserted into the body of the post, in the_content not appear on the instrument panel in the posts edit mode.

your solution above not write the posts, only displays the script running, I want to write, and the above function already written, but not write in dashoboard fields in post edit understand?

note: the cleaner function without so my foolish attempts is here:

function gen_num()
{
  global $post;
  $mixnames = get_post_meta( $post->ID, 'fieldnames', true );

  if ( '' == $mixnames ) {
    $input = array("Neo ", "Morpheus ", "Trinity ", "Cypher ", "Tank ","the flash ","superman ","wolverine ", "subzero ","scorpion ");
    $rand_keys = array_rand($input, 5);
    $mixnames = $input[$rand_keys[0]].$input[$rand_keys[1]].$input[$rand_keys[2]]
.$input[$rand_keys[3]].$input[$rand_keys[4]].$input[$rand_keys[5]];
    update_post_meta( $post->ID, 'fieldnames', $mixnames );
  }
  // DISPLAYS THE OUTCOME
  print $mixnames;
}

I was not able to apply, although we understand that you were clear, I am very noob to do so. excuse me by work.
thanks again, you have helped me a lot.

Thank you again for your help and for explanations 🙂
I have tried the code above, but does not write the posts or titles in yet,
I have a tests server on a free hosting just to make tests, that is where to trying these scripts, I would like to pass the login wordpress admin for testing, after resolved, you just copy and past here the solution, I have followed you on twitter to be able to write for private, fallow me also to activate private conversation that you send login wordpress, also I wrote a message for you on robert video. 🙂

I had forgotten to write the function call in single.php with:
<? php if (function_exists ( ‘insert_gen_num’)) {insert_gen_num ();}?>

but the values ​​change with each refresh, lack that condition to not re-write the values ​​change with each refresh (F5), lack that condition to not re-write the values ​​to each page access 🙂 is almost perfect, because the values ​​that I add manually are unchanged 🙂 and when access the post in edit mode the function data are really in great 🙂 post your idea 🙂
in dashboast F5 not rewrite values :)but in this new case, as it would be for the values ​​written by the function written stay even after refresh (F5) in the pages?

Thanks so much 🙂

/ * This function appears in the post editing and website so, but not permance the same writing, which prevents the use * /

function insert_gen_num( $post )
{
  $input = array("Neo ", "Morpheus ", "Trinity ", "Cypher ", "Tank ", "the flash ","superman ","wolverine ", "subzero ","scorpion ");
  $rand_keys = array_rand($input, 5);
  $mixnames = $input[$rand_keys[0]].$input[$rand_keys[1]].$input[$rand_keys[2]].$input[$rand_keys[3]].$input[$rand_keys[4]];
  $post->post_content = $mixnames . $post->post_content;
  $post->post_title = $mixnames . $post->post_title;
  wp_update_post( $post );
}
add_action('draft_to_publish', 'insert_gen_num');

/ * This function write and remains written but does not appear in the post fields in edit mode, which is very bad for me 🙁 * /

function insert_gen_num()
{
  global $post;
  $mixnames = get_post_meta( $post->ID, 'fieldnames', true );

  if ( '' == $mixnames ) {
    $input = array("Neo ", "Morpheus ", "Trinity ", "Cypher ", "Tank ","the flash ","superman ","wolverine ", "subzero ","scorpion ");
    $rand_keys = array_rand($input, 5);
    $mixnames = $input[$rand_keys[0]].$input[$rand_keys[1]].$input[$rand_keys[2]]
.$input[$rand_keys[3]].$input[$rand_keys[4]].$input[$rand_keys[5]];
    update_post_meta( $post->ID, 'fieldnames', $mixnames );
                         }
  // DISPLAYS THE OUTCOME
  print $mixnames;
}

Another interesting note is that all script only runs when I click refresh (F5), the first access the values ​​appear not yet! I would have to go into every page and press F5 !, being a very high page number, I would have to go entering 2000 pages and exit by pressing F5 to run the code!
Thank you so much.