How to use strpos to determine if a string exists in input string?
strpos returns false if the string is not found, and 0 if it is found at the beginning. Use the identity operator to distinguish the two:
if (strpos($filename, $match) === false) {By the way, this fact is documented with a red background and an exclamation mark in the official documentation.
The strpos() function is case-sensitive.
if(strpos($filename, $match) !== false) { // $match is present in $filename } else { // $match is not present in $filename }For using case-insensitive. use stripos() that is it finds the position of the first occurrence of a string inside another string (case-insensitive)