PHP check for double posting on the site

Question

I want to run a check when a user submits a form that will compare the new post to old once to avoid double (or more) postings of the same content.

I thought of something like

if(strtolower($string1) == strtolower($string2))
{
//do this
}

but not sure how that would work for checking an entire website full of posts with unique id's

Any help is much appreciated!

Answer 1

You could use the similar_text in PHP..

<?php 
$post1 = 'test1'; 
$post2 = 'test2'; 
similar_text($post1, $post2, $percent); 
if(round($percent)>90)
{
  echo "The two posts are 90% similar.. sorry try again. No spamming !";
}