trim() expects parameter 1 to be string, array given in - php

Question

I have this PHP function for converts all the html special characters to html entities, UTF-8 compatible.
function safe($input) {
$text = trim($input); //<-- LINE 31
$text = preg_replace("/(\r\n|\n|\r)/", "\n", $text); // cross-platform newlines
$text = preg_replace("/\n\n\n\n+/", "\n", $text); // take care of duplicates
$text = htmlspecialchars($text, ENT_QUOTES, 'UTF-8');
$text = stripslashes($text);
$text = str_replace ( "\n", " ", $text );
$text = str_replace ( "\t", " ", $text );
return $text;
}
Now, I check my script using acunetix web vuln scanner and i see this error :
This page contains an error/warning message that may disclose sensitive information.The message can also contain the location of the file that produced the unhandled exception.
This may be a false positive if the error message is found in documentation pages.
This vulnerability affects /cms/submit.php.
Discovered by: Scripting (Error_Message.script).
Attack details
URL encoded POST input access was set to 2
Error message found:
<b>Warning</b>: trim() expects parameter 1 to be string, array given in <b>C:\xampp\htdocs\cms\includes\safefunc.php</b> on line <b>31</b><br />
How do i fix this?

Answer 1

As others have said, the error is self explanatory and this function is not built to handle arrays. If you need to handle arrays then something like this:
function safe($input) {
if(is_array($input)) {
return array_map('safe', $input);
}
// rest of code
}

Answer 2

Read the Warning, and your answer is there.
Trim must receive a string as parameter, not a array.
Use
var_dump($input) to check your input variable type.
Could you show the code that call function safe()?

Answer 3

try to stringify the $input by using
json_encode($input)
it worked for me