If you have to both Encode or Decode a Base64 worth, there are various methods to attain this, considered one of them is instantly out of your commandline itself!
The right way to Encode a Base64 worth in CLI
echo 'It is a check' | base64
It will output a base64 encoded worth of
The right way to Decode a Base64 worth in CLI
echo VGhpcyBpcyBhIHRlc3QK | base64 --decode
It will output a decoded worth from our base64 worth of
It is a check