PHP port of the Python 2.7 `fnmatch::translate()` function to convert shell-expansion patterns to regular expressions.

python_fnmatch_translate.php

<?php
/**
 * Direct port of the Python 2.7 fnmatch::translate(pat) function.
 * Converts a shell-expansion pattern to a regular expression.
 *
 * by Steve Kamerman
 *
 * @see https://hg.python.org/cpython/file/2.7/Lib/fnmatch.py
 */
function pythonFnmatchTranslate($pat, $delimiter=null) {
    $i = 0;
    $n = strlen($pat);
    $res = '';

    while ($i < $n) {
        $c = $pat[$i];
        $i++;
        if ($c === '*') {
            $res .= '.*';
        } else if ($c === '?') {
            $res .= '.';
        } else if ($c === '[') {
            $j = $i;
            if ($j < $n && $pat[$j] === '!') {
                $j++;
            }
            if ($j < $n && $pat[$j] === ']') {
                $j++;
            }
            while ($j < $n && $pat[$j] !== ']') {
                $j++;
            }
            if ($j >= $n) {
                $res .= '\\[';
            } else {
                $stuff = substr($pat, $i, ($j - $i));
                $stuff = str_replace('\\','\\\\', $stuff);
                $i = $j + 1;
                if ($stuff[0] === '!') {
                    $stuff = '^' . substr($stuff, 1);
                } else if ($stuff[0] === '^') {
                    $stuff = '\\' . $stuff;
                }
                $res = sprintf('%s[%s]', $res, $stuff);
            }
        } else {
            $res .= preg_quote($c);
        }
    }

    $res = '^(?ms)' . $res . '$';

    // Unlike in Python, PHP requires delimiters.
    if ($delimiter !== null) {
        $res = str_replace($delimiter, '\\'.$delimiter, $res);
        $res = $delimiter . $res . $delimiter;
    }

    return $res;
}