FTP Error Codes

This is an excerpt/adaptation from RFC 640. Deviations from the RFC are not noted. Consider it all bogus.

Error Numbers

200  Command okay
500  Syntax error, command unrecognized [This may include errors such as command line too long.]
501  Syntax error in parameters or arguments
202  Command not imlemented, superfluous at this site. 
502  Command not implemented
503  Bad sequence of commands  
504  Command not implemented for that parameter 
110  Restart marker reply.
 	In this case the text is exact and not left to the particular implementation; it must read:
 	MARK yyyy = mmmm
 	where yyyy is User-process data stream marker, 
 	and mmmm is Server's equivalent marker.  (note the spaces between the markers and "=".) 
211  System status, or system help reply 
212  Directory status11j3
213  File status 
214  Help message (on how to use the server or the meaning of a particular non-standard command.  This reply is useful only to the human user.)
120  Service ready in nnn minutes 
220  Service ready for new user
221  Service closing TELNET connection (logged off if appropriate)
421  Service not available, closing TELNET connection. [This may be a reply to any command if the service knows it must shut down.] 
125  Data connection already open; transfer starting
225  Data connection open; no transfer in progress  
425  Can't open data connection
226  Closing data connection; requested file action successful (for example, file transfer or file abort.) 
426  Connection trouble, closed; transfer aborted.
227  Entering [passive, active] mode 
230  User logged on, proceed
530  Not logged in  
331  User name okay, need password
332  Need account for login
532  Need account for storing files
150  File status okay; about to open data connection. 
250  Requested file action okay, completed.  
350  Requested file action pending further information
450  Requested file action not taken: file unavailable (e.g. file not found, no access) 
550  Requested action not taken:  file unavailable (e.g. file busy)  
451  Requested action aborted: local error in processing
452  Requested action not taken:  insufficient storage space in system
552  Requested file action aborted:  exceeded storage allocation (for current directory or dataset)
553  Requested action not taken: file name not allowed
354  Start mail input; end with <CR><LF>.<CR><LF>

Interpreting Errors - What They Mean

There are four values for the first digit of the reply code:

1yz Positive Preliminary reply

The requested action is being initiated; expect another reply before proceeding with a new command. This type of reply can be used to indicate that the command was accepted.

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.

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.

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. Even some "permanent" error conditions can be corrected, so the human user may want to retry the command after conditions have changed.

The following function groupings are encoded in the second digit:

x0z Syntax

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 TELNET and data connections.

x3z Authentication and accounting

Replies for the logon process and accounting procedures.

x4z Unspecified

as yet

x5z File system

These replies indicate the status of the Server file system vis-a-vis the requested transfer or other file system action.