PHP Detect Duplicate Text

Question

I have a site where users can put in a description about themselves.

Most users write something appropriate but some just copy/paste the same text a number of times (to

Answer 1

You could use a regex, like this:

if (preg_match('/(.{10,})\\1{2,}/', $theText)) {
    echo "The string is repeated.";
}

Explanation:

• (.{10,}) looks for and captures a string that is at least 10 characters long
• \\1{2,} looks for the first string at least 2 more times

Possible tweaks to suit your needs:

• Change 10 to a higher or lower number to match longer or shorter repeated strings. I just used 10 as an example.
• If you want to catch even one repetition (love and peace love and peace), delete the {2,}. If you want to catch a higher number of repetitions, increase the 2.
• If you don't care how many times the repetition occurs, only that it occurs, delete the , in {2,}.