Hey guys am i doing it right or wrong? My intention is to decode hashes I just encoded of an image. How do I decode ? My code Need review ::

base64.php

<?php
// My intention is to decodeencrypted image hashes
// and export back to File(image.extension)
echo "Decrypt {string} or {file}? [input: \"str\" || \"bin\", type \"exit()\" for quit the programme]";
$__userInputOption = rtrim(fgets(STDIN));
if ($__userInputOption == "str"){
      echo "Please enter {string} you want to decode: \n";
      $_input = rtrim(fgets(STDIN));
      $_encodedString = base64_decode($_input);
      echo "Encoded String: ".$_input."\n";
      echo "Decoded String: ".$_encodedString;
} else if ($__userInputOption == "exit()") {
      exit();
} else if ($__userInputOption == "bin") {
      echo "Please enter {binary} you want to decode: \n";
      $__userInputBinary = rtrim(fgets(STDIN));
      $__post_decryption = file_get_contents($__userInputBinary);
      $__decryptedData = base64_decode($__post_decryption);
      // echo "Original binary".$__userInputBinary;
      echo "Decrypted binary hashes: ".$__decryptedData;
} else {
      printf("Please enter a valid input");
}

?>