Commands are not distinguished from options except for the fact that only one command is allowed. Generally speaking, irrelevant options are silently ignored, and may not be checked for correctness.
gpg may be run with no commands. In this case it will
perform a reasonable action depending on the type of file it is given
as input (an encrypted message is decrypted, a signature is verified,
a file containing keys is listed, etc.).
|• General GPG Commands:||Commands not specific to the functionality.|
|• Operational GPG Commands:||Commands to select the type of operation.|
|• OpenPGP Key Management:||How to manage your keys.|