Convert php file variables. methods and variables from snake case to camel case

convert-cammelcase.php

#!/usr/bin/env php
<?php

$path     = $argv[1];
$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($path));
foreach ($iterator as $file) {
    if (substr($file, -4) !== '.php') {
        continue;
    }
    echo "Converted: " . $file . PHP_EOL;
    $out = convert(file_get_contents($file));
    file_put_contents($file, $out);
}

/**
 * Convert string Snake case to Camel case
 * @param $val
 * @return string
 */
function snakeToCamel($val)
{
    if (in_array($val, array(
        '_SERVER',
        '_POST',
        '_GET',
        '_REQUEST',
        '_ENV',
        '_COOKIE',
        '_SESSION',
        '_FILES',
        'GLOBALS',
        'argc',
        'argv',
        'php_error_msg',
        'http_response_header',
    ))) {
        return $val;
    }

    $starts = array(
        "HTTP_",
    );
    foreach ($starts as $start) {
        if (strpos($val, $start) === 0) {
            return $val;
        }
    }

    preg_match('#^_*#', $val, $underscores);
    $underscores = current($underscores);
    $camel       = str_replace(' ', '', ucwords(str_replace('_', ' ', $val)));
    $camel       = strtolower(substr($camel, 0, 1)) . substr($camel, 1);

    return $underscores . $camel;
}

/**
 * Convert Snake case to Camel case
 * @param $str
 * @return string|string[]|null
 */
function convert($str)
{
    $name          = '[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*';
    $snakeRegexps = array(
        "#->($name)#i",
        '#\$(' . $name . ')#i',
        "#function ($name)#i",
    );
    foreach ($snakeRegexps as $regexp) {
        $str = preg_replace_callback($regexp, function ($matches) {
            $camel = snakeToCamel($matches[1]);
            return str_replace($matches[1], $camel, $matches[0]);
        }, $str);
    }

    return $str;
}