# Encrypt your file
encrypt my_text_file > my_encrypted_file
# ERROR! You try to decrypt the unencrypted file DON'T DO THIS
decrypt my_text_file > decrypted_file
gpg: no valid OpenPGP data found.
gpg: decrypt_message failed: Unknown system error
# You unencrypt the correct (encrypted) file and it works
decrypt my_encrypted_file > decrypted_file