Connected: An Internet Encyclopedia
4.1.3.1 Non-standard Command Verbs

Up: Connected: An Internet Encyclopedia
Up: Requests For Comments
Up: RFC 1123
Up: 4. FILE TRANSFER
Up: 4.1 FILE TRANSFER PROTOCOL -- FTP
Up: 4.1.3 SPECIFIC ISSUES
Prev: 4.1.3 SPECIFIC ISSUES
Next: 4.1.3.2 Idle Timeout

4.1.3.1 Non-standard Command Verbs

4.1.3.1 Non-standard Command Verbs

FTP allows "experimental" commands, whose names begin with "X". If these commands are subsequently adopted as standards, there may still be existing implementations using the "X" form. At present, this is true for the directory commands:

        RFC-959   "Experimental"

          MKD        XMKD
          RMD        XRMD
          PWD        XPWD
          CDUP       XCUP
          CWD        XCWD

All FTP implementations SHOULD recognize both forms of these commands, by simply equating them with extra entries in the command lookup table.

IMPLEMENTATION:

A User-FTP can access a server that supports only the "X" forms by implementing a mode switch, or automatically using the following procedure: if the RFC-959 form of one of the above commands is rejected with a 500 or 502 response code, then try the experimental form; any other response would be passed to the user.


Next: 4.1.3.2 Idle Timeout

Connected: An Internet Encyclopedia
4.1.3.1 Non-standard Command Verbs