Reply |
Short Description |
Detailed Description |
1yz |
Positive Preliminary Reply |
The requested action is being initiated; expect another
reply before proceeding with a new command. (The
user-process sending another command before the
completion reply would be in violation of protocol; but
server-FTP processes should queue any commands that
arrive while a preceding command is in progress.) This
type of reply can be used to indicate that the command
was accepted and the user-process may now pay attention
to the data connections, for implementations where
simultaneous monitoring is difficult. The server-FTP
process may send at most, one 1yz reply per command. |
2yz |
Positive Completion Reply |
The requested action has been successfully completed. A
new request may be initiated. |
3yz |
Positive Intermediate Reply |
The command has been accepted, but the requested action
is being held in abeyance, pending receipt of further
information. The user should send another command
specifying this information. This reply is used in
command sequence groups. |
4yz |
Transient Negative Completion Reply |
The command was not accepted and the requested action did
not take place, but the error condition is temporary and
the action may be requested again. The user should
return to the beginning of the command sequence, if any.
It is difficult to assign a meaning to "transient",
particularly when two distinct sites (Server- and
User-processes) have to agree on the interpretation.
Each reply in the 4yz category might have a slightly
different time value, but the intent is that the
user-process is encouraged to try again. A rule of thumb
in determining if a reply fits into the 4yz or the 5yz
(Permanent Negative) category is that replies are 4yz if
the commands can be repeated without any change in
command form or in properties of the User or Server
(e.g., the command is spelled the same with the same
arguments used; the user does not change his file access
or user name; the server does not put up a new
implementation.) |
5yz |
Permanent Negative Completion Reply |
The command was not accepted and the requested action did
not take place. The User-process is discouraged from
repeating the exact request (in the same sequence). Even
some "permanent" error conditions can be corrected, so
the human user may want to direct his User-process to
reinitiate the command sequence by direct action at some
point in the future (e.g., after the spelling has been
changed, or the user has altered his directory status.) |
x0z |
Syntax Error |
These replies refer to syntax errors,
syntactically correct commands that don't fit any
functional category, unimplemented or superfluous
commands. |
x1z |
Information |
These are replies to requests for information, such as
status or help. |
x2z |
Connections |
Replies referring to the control and data connections. |
x3z |
Authentication and Accounting |
Replies for the login process and accounting procedures. |
x4z |
Unspecified |
Unspecified |
x5z |
Filesystem status |
These replies indicate the status of the
Server file system vis-a-vis the requested transfer or
other file system action. |