How to replicate openssl encrypt/decrypt between PHP and Command Line?

Question

I am trying to create a PHP method to replicate the OpenSSL command line function so I can encrypt using the command line and then decrypt it using PHP or the opposite by encrypting using PHP and then decrypting using the command line.

the command line that is needed and this is fixed, I can not change it. I need to replicate it in PHP

openssl  enc -aes-256-cbc -in original.txt -out encrypted.bin -pass file:unwrappedoaep.key

I tried the below in PHP to replicate the above command line but it is not working.

$key = file_get_contents('unwrappedoaep.key');
$key = bin2hex($key);
$iv = '';

$data = file_get_contents('original.txt');
$encrypted = openssl_encrypt($data, 'AES-256-CBC', $key, OPENSSL_RAW_DATA, $iv);

the above generated $encrypted string needs to be decrypted using the below command line, but it failed and got bad magic number , I need to modify the above PHP code to be able to generate an encrypted file similar to the one created using the command line to be able to decrypt it using the below command as it is exactly

openssl  enc -d -aes-256-cbc -in encrypted.bin -out decrypted.txt -pass file:unwrappedoaep.key

---

I try to decrypt a file encrypted by the command line, I use below PHP code as mentioned by @Topaco:

$salt = substr($encrypted, 8, 8);   //ignore first 8 'Salted__'
$ciphertext = substr($encrypted, 16);
$keyIv = EVP_BytesToKey($salt, $secret);
$key = substr($keyIv, 0, 32);
$iv = substr($keyIv, 32);

$original = openssl_decrypt($ciphertext, 'AES-256-CBC', $key, OPENSSL_RAW_DATA, $iv);

where the function EVP_BytesToKey is defined:

function EVP_BytesToKey($salt, $password) {
    $bytes = '';
    $last = '';
    while(strlen($bytes) < 48) {
        $last = hash('sha256', $last . $password . $salt, true);
        $bytes.= $last;
    }
    return $bytes;
}

it is working if I create a file with a text inside it and in the command line use -pass file:unwrappedoaep.key and in the PHP replace the $secret with file_get_contents('unwrappedoaep.key')

but when i but in the unwrappedoaep.key a binary not a text then the decrypt from php method is not working anymore.