如何在从末尾匹配的字符串中获取模式的位置

Question

$a = "this is school of sachin";
$pattern = "sch";

I want to get the position of the pattern matched from the end. For example in this case, sch matches school -- so the position of the pattern should be 3, i.e. from the end:

as mentioned below the index for the word school are arranged in this manner,so if the match of sch is successful than the position from the end of the word which is getting matched(school) and to the start of the pattern(from the end) should be returned.

s c h o o l
5 4 3 2 1 0

^---^

matched pattern.

I have tried strpos() but could not make it to serve my purpose.

echo strpos($a, $pattern); // this is wrong 

The output of strpos() should be 3 according to my question.

Answer 1

<?php
$a = "this is school of sachin";
$pattern = "sch";
$words = explode(" ", $a);
$pattern = strrev($pattern);
foreach($words as $word){
$pos = strpos(strrev($word), $pattern);
    if($pos !== false){
    print($pos);
    break;
    }
}
?>

OR

<?php
$a = "this is sachinùs school of sachin";
$pattern = "sach";
if(preg_match("/[^ [:punct:]]*".$pattern."([^ [:punct:]]*)/u", $a, $match)){
print(mb_strlen($match[1], "UTF-8"));
    if($pattern == $match[0]){
    print(" (full word)");
    }
}
?>