Convert (unescape) all hex and octal chars into readable text

convert_hex-octal_to_text.php

<?php

/**
 * Try to convert (unescape) all hex and octal chars into readable text
 * '\x4e\145\166\x65\162\40\164\150\162\x6f\167\156' -> 'Never thrown'
 */
 
$file = __DIR__ . '/my.file';

$string = file_get_contents($file);

// convert octal part to readable text
$string = preg_replace_callback('/\\\\([0-7]{1,3})/', static function ($m) {
    return mb_convert_encoding(chr(octdec($m[1])), 'UTF-8');
}, $string);

// convert hexadecimal part to readable text
$string = preg_replace_callback('/\\\\x([0-9A-F]{1,2})/i', static function ($m) {
    return mb_convert_encoding(chr(hexdec($m[1])), 'UTF-8');
}, $string);

file_put_contents($file . '.converted', $string);