Use the ABORT command to abandon a file-in-transit.
The purpose of the ABORT command is to indicate client-initiated cancel or client-detected failure.
An ABORT statement must come before any EOF or QUIT command.
The syntax is
The ABORT command has no parameters.
The ABORT command is, like all other "commands",
sent from the client to the server.
Servers indicate failure with a 5xx response code, not with ABORT.