1 SESSION LAYER PROTOCOL FOR CITADEL/UX
2 (c) 1995-1999 by Art Cancro et. al. All Rights Reserved
8 This is an attempt to document the session layer protocol used by the
9 Citadel/UX system, beginning with version 4.00, which is the first version
10 to implement a client/server paradigm. It is intended as a resource for
11 programmers who intend to develop their own Citadel clients, but it may have
15 IMPORTANT NOTE TO DEVELOPERS!
16 -----------------------------
18 Anyone who wants to add commands or other functionality to this protocol,
19 *please* get in touch so that these efforts can be coordinated. New
20 commands added by other developers can be added to this document, so we
21 don't end up with new server commands from multiple developers which have
22 the same name but perform different functions. If you don't coordinate new
23 developments ahead of time, please at least send in an e-mail documenting
24 what you did, so that your new commands can be added to this document.
26 The coordinator of the Citadel/UX project is Art Cancro <ajc@uncnsrd.mt-kisco.ny.us>.
29 CONNECTING TO A SERVER
30 ----------------------
32 The protocols used below the session layer are beyond the scope of this
33 document, but we will briefly cover the methodology employed by Citadel/UX.
35 Citadel/UX offers Citadel BBS service using TCP/IP. It does so via a
36 multithreaded server listening on a TCP port. Older (4.xx) versions employed
37 an inetd-based server.
39 The port number officially assigned to Citadel by the IANA is TCP/504. Since
40 our session layer assumes a clean, reliable, sequenced connection, the use
41 of UDP would render the server unstable and unusable, so we stick with TCP.
44 GENERAL INFORMATION ABOUT THE SERVER
45 ------------------------------------
47 The server is connection-oriented and stateful: each client requires its own
48 connection to a server process, and when a command is sent, the client must
49 read the response, and then transfer data or change modes if necessary.
51 The session layer is very much like other Internet protocols such as SMTP
52 or NNTP. A client program sends one-line commands to the server, and the
53 server responds with a three-digit numeric result code followed by a message
54 describing what happened. This cycle continues until the end of the
57 Unlike protocols such as FTP, all data transfers occur in-band. This means
58 that the same connection that is used for exchange of client/server
59 messages, will also be used to transfer data back and forth. (FTP opens a
60 separate connection for data transfers.) We do this to allow the server to
61 function over transports which can only handle one session at a time (such
62 as a dialup connection).
68 The server will respond to all commands with a 3-digit result code, which
69 will be the first three characters on the line. The rest of the line may
70 contain a human-readable string explaining what happened. (Some client
71 software will display some of these strings to the user.)
73 The first digit is the most important. The following codes are defined for
74 this position: ERROR, OK, MORE_DATA, LISTING_FOLLOWS, and SEND_LISTING.
76 The second and third digits may provide a reason as to why a command
77 succeeded or failed. See ipcdef.h for the available codes.
79 ERROR means the command did not complete.
80 OK means the command executed successfully.
81 MORE_DATA means the command executed partially. Usually this means that
82 another command needs to be executed to complete the operation. For example,
83 sending the USER command to log in a user usually results in a MORE_DATA
84 result code, because the client needs to execute a PASS command to send the
85 password and complete the login.
86 LISTING_FOLLOWS means that after the server response, the server will
87 output a listing of some sort. The client *must* read the listing, whether
88 it wants to or not. The end of the listing is signified by the string
89 "000" on a line by itself.
90 SEND_LISTING is the opposite of LISTING_FOLLOWS. It means that the client
91 should begin sending a listing of some sort. The client *must* send something,
92 even if it is an empty listing. Again, the listing ends with "000" on a line
99 Zero or more parameters may be passed to a command. When more than one
100 parameter is passed to a command, they should be separated by the "|"
103 In this example, we're using the "SETU" command and passing three
104 parameters: 80, 24, and 260.
106 When the server spits out data that has parameters, if more than one
107 parameter is returned, they will be separated by the "|" symbol like
110 In this example, we just executed the "GETU" command, and it returned us
111 an OK result code (the '2' in the 200) and three parameters: 80, 24, and
118 This is a listing of all the commands that a Citadel/UX server can execute.
123 This command does nothing. It takes no arguments and always returns
124 OK. It is intended primarily for testing and development, but it might also
125 be used as a "keep alive" command to prevent the server from timing out, if
126 it's running over a transport that needs this type of thing.
129 ECHO (ECHO something)
131 This command also does nothing. It simply returns OK followed by whatever
137 Terminate the server connection. This command takes no arguments. It
138 returns OK and closes the connection immediately.
143 Log out the user without closing the server connection. It always returns
144 OK even if no user is logged in.
147 USER (send USER name)
149 The first step in logging in a user. This command takes one argument: the
150 name of the user to be logged in. If the user exists, a MORE_DATA return
151 code will be sent, which means the client should execute PASS as the next
152 command. If the user does not exist, ERROR is returned.
157 The second step in logging in a user. This command takes one argument: the
158 password for the user we are attempting to log in. If the password doesn't
159 match the correct password for the user we specified for the USER command,
160 or if a USER command has not been executed yet, ERROR is returned. If the
161 password is correct, OK is returned and the user is now logged in... and
162 most of the other server commands can now be executed. Along with OK, the
163 following parameters are returned:
165 0 - The user's name (in case the client wants the right upper/lower casing)
166 1 - The user's current access level
169 4 - Various flags (see citadel.h)
173 NEWU (create NEW User account)
175 This command creates a new user account and logs it in. The argument to
176 this command will be the name of the account. No case conversion is done
177 on the name. Note that the new account is installed with a default
178 configuration, and no password, so the client should immediately prompt the
179 user for a password and install it with the SETP command as soon as this
180 command completes. This command returns OK if the account was created and
181 logged in, or ERROR if another user already exists with this name. If OK,
182 it will also return the same parameters that PASS returns.
185 SETP (SET new Password)
187 This command sets a new password for the currently logged in user. The
188 argument to this command will be the new password. The command always
189 returns OK, unless the client is not logged in, in which case it will return
193 LKRN (List Known Rooms with New messages)
195 List known rooms with new messages. If the client is not logged in, ERROR
196 is returned. Otherwise, LISTING_FOLLOWS is returned, followed by the room
197 listing. Each line in the listing contains the full name of a room, followed
198 by the '|' symbol, and then a number that may contain the following bits:
201 #define QR_PERMANENT 1 /* Room does not purge */
202 #define QR_PRIVATE 4 /* Set for any type of private room */
203 #define QR_PASSWORDED 8 /* Set if there's a password too */
204 #define QR_GUESSNAME 16 /* Set if it's a guessname room */
205 #define QR_DIRECTORY 32 /* Directory room */
206 #define QR_UPLOAD 64 /* Allowed to upload */
207 #define QR_DOWNLOAD 128 /* Allowed to download */
208 #define QR_VISDIR 256 /* Visible directory */
209 #define QR_ANONONLY 512 /* Anonymous-Only room */
210 #define QR_ANON2 1024 /* Anonymous-Option room */
211 #define QR_NETWORK 2048 /* Shared network room */
212 #define QR_PREFONLY 4096 /* Preferred status needed to enter */
213 #define QR_READONLY 8192 /* Aide status required to post */
216 Other bits may be defined in the future. The listing terminates, as with
217 all listings, with "000" on a line by itself.
219 Starting with version 4.01 and above, floors are supported. The first
220 argument to LKRN should be the number of the floor to list rooms from. Only
221 rooms from this floor will be listed. If no arguments are passed to LKRN, or
222 if the floor number requested is (-1), rooms on all floors will be listed.
224 The third field displayed on each line is the number of the floor the room
225 is on. The LFLR command should be used to associate floor numbers with
228 The fourth field displayed on each line is a "room listing order." Unless
229 there is a compelling reason not to, clients should sort any received room
230 listings by this value.
234 LKRO (List Known Rooms with Old [no new] messages)
236 This follows the same usage and format as LKRN.
239 LZRM (List Zapped RooMs)
241 This follows the same usage and format as LKRN and LKRO.
244 LKRA (List All Known Rooms)
246 Same format. Lists all known rooms, with or without new messages.
249 LRMS (List all accessible RooMS)
251 Again, same format. This command lists all accessible rooms, known and
252 forgotten, with and without new messages. It does not, however, list
253 inaccessible private rooms.
256 GETU (GET User configuration)
258 This command retrieves the screen dimensions and user options for the
259 currently logged in account. ERROR will be returned if no user is logged
260 in, of course. Otherwise, OK will be returned, followed by three parameters.
261 The first parameter is the user's screen width, the second parameter is the
262 user's screen height, and the third parameter is a bag of bits with the
265 #define US_LASTOLD 16 /* Print last old message with new */
266 #define US_EXPERT 32 /* Experienced user */
267 #define US_UNLISTED 64 /* Unlisted userlog entry */
268 #define US_NOPROMPT 128 /* Don't prompt after each message */
269 #define US_DISAPPEAR 512 /* Use "disappearing msg prompts" */
270 #define US_PAGINATOR 2048 /* Pause after each screen of text */
272 There are other bits, too, but they can't be changed by the user (see below).
275 SETU (SET User configuration)
277 This command does the opposite of SETU: it takes the screen dimensions and
278 user options (which were probably obtained with a GETU command, and perhaps
279 modified by the user) and writes them to the user account. This command
280 should be passed three parameters: the screen width, the screen height, and
281 the option bits (see above).
283 Note that there exist bits here which are not listed in this document. Some
284 are flags that can only be set by Aides or the system administrator. SETU
285 will ignore attempts to toggle these bits. There also may be more user
286 settable bits added at a later date. To maintain later downward compatibility,
287 the following procedure is suggested:
289 1. Execute GETU to read the current flags
290 2. Toggle the bits that we know we can toggle
291 3. Execute SETU to write the flags
293 If we are passed a bit whose meaning we don't know, it's best to leave it
294 alone, and pass it right back to the server. That way we can use an old
295 client on a server that uses an unknown bit without accidentally clearing
296 it every time we set the user's configuration.
301 This command is used to goto a new room. When the user first logs in (login
302 is completed after execution of the PASS command) this command is
303 automatically and silently executed to take the user to the first room in the
304 system (usually called the Lobby).
306 This command can be passed one or two parameters. The first parameter is,
307 of course, the name of the room. Although it is not case sensitive, the
308 full name of the room must be used. Wildcard matching or unique string
309 matching of room names should be the responsibility of the client.
311 Note that the reserved room name "_BASEROOM_" can be passed to the server
312 to cause the goto command to take the user to the first room in the system,
313 traditionally known as the Lobby>. As long as a user is logged in, a
314 GOTO command to _BASEROOM_ is guaranteed to succeed. This is useful to
315 allow client software to return to the base room when it doesn't know
318 There are also two additional reserved room names:
319 "_MAIL_" translates to the system's designated room for e-mail messages.
320 "_BITBUCKET_" goes to whatever room has been chosen for messages
323 The second (and optional) parameter is a password, if one is required for
324 access to the room. This allows for all types of rooms to be accessed via
325 this command: for public rooms, invitation-only rooms to which the user
326 has access, and preferred users only rooms to which the user has access, the
327 room will appear in a room listing. For guess-name rooms, this command
328 will work transparently, adding the room to the user's known room list when
329 it completes. For passworded rooms, access will be denied if the password
330 is not supplied or is incorrect, or the command will complete successfully
331 if the password is correct.
333 The possible result codes are:
335 OK - The command completed successfully. User is now in the room.
336 (See the list of returned parameters below)
338 ERROR - The command did not complete successfully. Check the second and
339 third positions of the result code to find out what happened:
341 NOT_LOGGED_IN - Of course you can't go there. You didn't log in.
342 PASSWORD_REQUIRED - Either a password was not supplied, or the supplied
343 password was incorrect.
344 NO_SUCH_ROOM - The requested room does not exist.
346 The typical procedure for entering a passworded room would be:
348 1. Execute a GOTO command without supplying any password.
349 2. ERROR+PASSWORD_REQUIRED will be returned. The client now knows that
350 the room is passworded, and prompts the user for a password.
351 3. Execute a GOTO command, supplying both the room name and the password.
352 4. If OK is returned, the command is complete. If, however,
353 ERROR+PASSWORD_REQUIRED is still returned, tell the user that the supplied
354 password was incorrect. The user remains in the room he/she was previously
357 When the command succeeds, these parameters are returned:
358 0. The name of the room
359 1. Number of unread messages in this room
360 2. Total number of messages in this room
361 3. Info flag: set to nonzero if the user needs to read this room's info
362 file (see RINF command below)
363 4. Various flags associated with this room. (See LKRN cmd above)
364 5. The highest message number present in this room
365 6. The highest message number the user has read in this room
366 7. Boolean flag: 1 if this is a Mail> room, 0 otherwise.
367 8. Aide flag: 1 if the user is either the Room Aide for this room, *or* is
368 a regular Aide (this makes access checks easy).
369 9. The number of new Mail messages the user has (useful for alerting the
370 user to the arrival of new mail during a session)
371 10. The floor number this room resides on
374 MSGS (get pointers to MeSsaGeS in this room)
376 This command obtains a listing of all the messages in the current room
377 which the client may request. This command may be passed a single parameter:
378 either "all", "old", or "new" to request all messages, only old messages, or
379 new messages. Or it may be passed two parameters: "last" plus a number, in which
380 case that many message pointers will be returned, or "first" plus a number, for
381 the corresponding effect. If no parameters are specified, "all" is assumed.
383 In Citadel/UX 5.00 and above, the client may also specify "gt" plus a number, to
384 list all messages in the current room with a message number greater than the one
387 This command can return two possible results. An ERROR code may be returned
388 if no user is currently logged in or if something else went wrong. Otherwise,
389 LISTING_FOLLOWS will be returned, and the listing will consist of zero or
390 more message numbers, one per line. The listing ends, as always, with the
391 string "000" alone on a line by itself. The listed message numbers can be used
392 to request messages from the system.
395 MSG0 (read MeSsaGe, mode 0)
397 This is a command used to read the text of a message. "Mode 0" implies that
398 other MSG commands (MSG1, MSG2, etc.) will probably be added later on to read
399 messages in more robust formats. This command should be passed two arguments.
400 The first is the message number of the message being requested. In server
401 version 4.04 and above, the second argument may be set to either 0 to read the
402 entire message, or 1 to read the headers only.
404 The server should, of course, make sure that the client actually has access
405 to the message being requested before honoring this request. Citadel/UX does
406 so by checking the message number against the contents of the current room. If
407 it's not there, the request is denied.
409 If the request is denied, an ERROR code will be returned. Otherwise, the
410 LISTING_FOLLOWS code will be returned, followed by the contents of the message.
411 The following fields may be sent:
413 type= Formatting type. The currently defined types are:
414 0 = "traditional" Citadel formatting. This means that newlines should be
415 treated as spaces UNLESS the first character on the next line is a space. In
416 other words, only indented lines should generate a newline on the user's screen
417 when the message is being displayed. This allows a message to be formatted to
418 the reader's screen width. It also allows the use of proportional fonts.
419 1 = a simple fixed-format message. The message should be displayed to
420 the user's screen as is, preferably in a fixed-width font that will fit 80
422 4 = MIME format message. The message text is expected to contain a header
423 with the "Content-type:" directive (and possibly others).
425 msgn= The message ID of this message on the system it originated on.
426 path= An e-mailable path back to the user who wrote the message.
428 time= The date and time of the message, in Unix format (the number of
429 seconds since midnight on January 1, 1970, GMT).
431 from= The name of the author of the message.
432 rcpt= If the message is a private e-mail, this is the recipient.
433 room= The name of the room the message originated in.
434 node= The short node name of the system this message originated on.
435 hnod= The long node name of the system this message originated on.
437 text Note that there is no "=" after the word "text". This string
438 signifies that the message text begins on the next line.
441 WHOK (WHO Knows room)
443 This command is available only to Aides. ERROR+HIGHER_ACCESS_REQUIRED will
444 be returned if the user is not an Aide. Otherwise, it returns
445 LISTING_FOLLOWS and then lists, one user per line, every user who has
446 access to the current room.
449 INFO (get server INFO)
451 This command will *always* return LISTING_FOLLOWS and then print out a
452 listing of zero or more strings. Client software should be written to expect
453 anywhere from a null listing to an infinite number of lines, to allow later
454 backward compatibility. The current implementation defines the following
455 parts of the listing:
457 Line 1 - Your unique session ID on the server
458 Line 2 - The node name of the server BBS
459 Line 3 - Human-readable node name of the server BBS
460 Line 4 - The fully-qualified domain name (FQDN) of the server
461 Line 5 - The name of the server software, i.e. "Citadel/UX 4.00"
462 Line 6 - (The revision level of the server code) * 100
463 Line 7 - The geographical location of the BBS (city and state if in the US)
464 Line 8 - The name of the system administrator
465 Line 9 - A number identifying the server type (see below)
466 Line 10 - The text of the system's paginator prompt
467 Line 11 - Floor Flag. 1 if the system supports floors, 0 otherwise.
468 Line 12 - Paging level. 0 if the system only supports inline paging,
469 1 if the system supports "extended" paging (check-only and
470 multiline modes). See the SEXP command for further information.
472 *** NOTE! *** The "server type" code is intended to promote global
473 compatibility in a scenario in which developers have added proprietary
474 features to their servers or clients. We are attempting to avoid a future
475 situation in which users need to keep different client software around for
476 each BBS they use. *Please*, if you are a developer and plan to add
477 proprietary features:
479 -> Your client programs should still be able to utilize servers other than
481 -> Clients other than your own should still be able to utilize your server,
482 even if your proprietary extensions aren't supported.
483 -> Please contact Art Cancro <ajc@uncnsrd.mt-kisco.ny.us> and obtain a unique
484 server type code, which can be assigned to your server program.
485 -> If you document what you did in detail, perhaps it can be added to a
486 future release of the Citadel/UX program, so everyone can enjoy it. Better
487 yet, just work with the Citadel development team on the main source tree.
489 If everyone follows this scheme, we can avoid a chaotic situation with lots
490 of confusion about which client program works with which server, etc. Client
491 software can simply check the server type (and perhaps the revision level)
492 to determine ahead of time what commands may be utilized.
494 Please refer to "developers.txt" for information on what codes belong to whom.
498 RDIR (Read room DIRectory)
500 Use this command to read the directory of a directory room. ERROR+NOT_HERE
501 will be returned if the room has no directory, or some other error; ERROR +
502 HIGHER_ACCESS_REQUIRED will be returned if the room's directory is not
503 visible and the user does not have Aide or Room Aide privileges; otherwise
504 LISTING_FOLLOWS will be returned, followed by the room's directory. Each
505 line of the directory listing will contain three fields: a filename, the
506 length of the file, and a description.
508 The server message contained on the same line with LISTING_FOLLOWS will
509 contain the name of the system and the name of the directory, such as:
510 uncnsrd.mt-kisco.ny.us|/usr/bbs/files/my_room_directory
513 SLRP (Set Last-message-Read Pointer)
515 This command is used to mark messages as having been read. Its sole parameter
516 is the number of the last message that has been read. This allows the pointer
517 to be set at any arbitrary point in the room. Optionally, the parameter
518 "highest" may be used instead of a message number, to set the pointer to the
519 number of the highest message in the room, effectively marking all messages
520 in the room as having been read (ala the Citadel <G>oto command).
522 The command will return OK if the pointer was set, or ERROR if something
523 went wrong. If OK is returned, it will be followed by a single argument
524 containing the message number the last-read-pointer was set to.
527 INVT (INViTe a user to a room)
529 This command may only be executed by Aides, or by the room aide for the
530 current room. It is used primarily to add users to invitation-only rooms,
531 but it may also be used in other types of private rooms as well. Its sole
532 parameter is the name of the user to invite.
534 The command will return OK if the operation succeeded, or ERROR if it did
535 not. ERROR+HIGHER_ACCESS_REQUIRED may also be returned if the operation
536 would have been possible if the user had higher access, and ERROR+NOT_HERE
537 may be returned if the room is not a private room.
540 KICK (KICK a user out of a room)
542 This is the opposite of INVT: it is used to kick a user out of a private
543 room. It can also be used to kick a user out of a public room, but the
544 effect will only be the same as if the user <Z>apped the room - a non-stupid
545 user can simply un-zap the room to get back in.
548 GETR (GET Room attributes)
550 This command is used for editing the various attributes associated with a
551 room. A typical "edit room" command would work like this:
552 1. Use the GETR command to get the current attributes
553 2. Change some of them around
554 3. Use SETR (see below) to save the changes
555 4. Possibly also change the room aide using the GETA and SETA commands
557 GETR takes no arguments. It will only return OK if the SETR command will
558 also return OK. This allows client software to tell the user that he/she
559 can't edit the room *before* going through the trouble of actually doing the
560 editing. Possible return codes are:
562 ERROR+NOT_LOGGED_IN - No user is logged in.
563 ERROR+HIGHER_ACCESS_REQUIRED - Not enough access. Typically, only aides
564 and the room aide associated with the current room, can access this command.
565 ERROR+NOT_HERE - Lobby>, Mail>, and Aide> cannot be edited.
566 OK - Command succeeded. Parameters are returned.
568 If OK is returned, the following parameters will be returned as well:
570 0. The name of the room
571 1. The room's password (if it's a passworded room)
572 2. The name of the room's directory (if it's a directory room)
573 3. Various flags (bits) associated with the room (see LKRN cmd above)
574 4. The floor number on which the room resides
575 5. The room listing order
578 SETR (SET Room attributes)
580 This command sets various attributes associated with the current room. It
581 should be passed the following arguments:
583 0. The name of the room
584 1. The room's password (if it's a passworded room)
585 2. The name of the room's directory (if it's a directory room)
586 3. Various flags (bits) associated with the room (see LKRN cmd above)
587 4. "Bump" flag (see below)
588 5. The floor number on which the room should reside
589 6. The room listing order
591 *Important: You should always use GETR to retrieve the current attributes of
592 the room, then change what you want to change, and then use SETR to write it
593 all back. This is particularly important with respect to the flags: if a
594 particular bit is set, and you don't know what it means, LEAVE IT ALONE and
595 only toggle the bits you want to toggle. This will allow for upward
598 If the room is a private room, you have the option of causing all users who
599 currently have access, to forget the room. If you want to do this, set the
600 "bump" flag to 1, otherwise set it to 0.
605 This command is used to get the name of the Room Aide for the current room.
606 It will return ERROR+NOT_LOGGED_IN if no user is logged in, ERROR if there
607 is no current room, or OK if the command succeeded. Along with OK there will
608 be returned one parameter: the name of the Room Aide.
613 The opposite of GETA, used to set the Room Aide for the current room. One
614 parameter should be passed, which is the name of the user who is to be the
615 new Room Aide. Under Citadel/UX, this command may only be executed by Aides
616 and by the *current* Room Aide for the room. Return codes possible are:
617 ERROR+NOT_LOGGED_IN (Not logged in.)
618 ERROR+HIGHER_ACCESS_REQUIRED (Higher access required.)
619 ERROR+NOT_HERE (No current room, or room cannot be edited.
620 Under Citadel/UX, the Lobby> Mail> and Aide> rooms are non-editable.)
621 OK (Command succeeded.)
624 ENT0 (ENTer message, mode 0)
626 This command is used to enter messages into the system. It accepts four
629 0 - Post flag. This should be set to 1 to post a message. If it is
630 set to 0, the server only returns OK or ERROR (plus any flags describing
631 the error) without reading in a message. Client software should, in fact,
632 perform this operation at the beginning of an "enter message" command
633 *before* starting up its editor, so the user does not end up typing a message
634 in vain that will not be permitted to be saved. If it is set to 2, the
635 server will accept an "apparent" post name if the user is privileged enough.
636 This post name is arg 4.
637 1 - Recipient. This argument is utilized only for private mail messages.
638 It is ignored for public messages. It contains, of course, the name of the
639 recipient of the message.
640 2 - Anonymous flag. This argument is ignored unless the room allows
641 anonymous messages. In such rooms, this flag may be set to 1 to flag a
642 message as anonymous, otherwise 0 for a normal message.
643 3 - Format type. Any valid Citadel/UX format type may be used (this will
644 typically be 0; see the MSG0 command above).
645 4 - Post name. When postflag is 2, this is the name you are posting as.
646 This is an Aide only command.
648 Possible result codes:
649 OK - The request is valid. (Client did not set the "post" flag, so the
650 server will not read in message text.) If the message is an e-mail with
651 a recipient, the text that follows the OK code will contain the exact name
652 to which mail is being sent. The client can display this to the user. The
653 implication here is that the name that the server returns will contain the
654 correct upper and lower case characters. In addition, if the recipient is
655 having his/her mail forwarded, the forwarding address will be returned.
656 SEND_LISTING - The request is valid. The client should now transmit
657 the text of the message (ending with a 000 on a line by itself, as usual).
658 ERROR - Miscellaneous error. (Explanation probably follows.)
659 ERROR + NOT_LOGGED_IN - Not logged in.
660 ERROR + HIGHER_ACCESS_REQUIRED - Higher access is required. An
661 explanation follows, worded in a form that can be displayed to the user.
662 ERROR + NO_SUCH_USER - The specified recipient does not exist.
665 RINF (read Room INFormation file)
667 Each room has associated with it a text file containing a description of
668 the room, perhaps containing its intended purpose or other important
669 information. The info file for the Lobby> (the system's base room) is
670 often used as a repository for system bulletins and the like.
672 This command, which accepts no arguments, is simply used to read the info
673 file for the current room. It will return LISTING_FOLLOWS followed by
674 the text of the message (always in format type 0) if the request can be
675 honored, or ERROR if no info file exists for the current room (which is
676 often the case). Other error description codes may accompany this result.
678 When should this command be used? This is, of course, up to the discretion
679 of client software authors, but in Citadel it is executed in two situations:
680 the first time the user ever enters a room; and whenever the contents of the
681 file change. The latter can be determined from the result of a GOTO command,
682 which will tell the client whether the file needs to be read (see GOTO above).
685 DELE (DELEte a message)
687 Delete a message from the current room. The one argument that should be
688 passed to this command is the message number of the message to be deleted.
689 The return value will be OK if the message was deleted, or an ERROR code.
692 MOVE (MOVE a message to a different room)
694 Move a message to a different room. The two arguments that should be passed
695 to this command are the message number of the message to be deleted, and the
696 name of the target room. If the operation succeeds, the message will be
697 deleted from the current room and moved to the target room. An ERROR code
698 usually means that either the user does not have permission to perform this
699 operation, or that the target room does not exist.
702 KILL (KILL current room)
704 This command deletes the current room. It accepts a single argument, which
705 should be nonzero to actually delete the room, or zero to merely check
706 whether the room can be deleted.
708 Once the room is deleted, the current room is undefined. It is suggested
709 that client software immediately GOTO another room (usually _BASEROOM_)
710 after this command completes.
712 Possible return codes:
714 OK - room has been deleted (or, if checking only, request is valid).
715 ERROR+NOT_LOGGED_IN - no user is logged in.
716 ERROR+HIGHER_ACCESS_REQUIRED - not enough access to delete rooms.
717 ERROR+NOT_HERE - this room can not be deleted.
720 CRE8 (CRE[ate] a new room)
722 This command is used to create a new room. Like some of the other
723 commands, it provides a mechanism to first check to see if a room can be
724 created before actually executing the command. CRE8 accepts the following
727 0 - Create flag. Set this to 1 to actually create the room. If it is
728 set to 0, the server merely checks that there is a free slot in which to
729 create a new room, and that the user has enough access to create a room. It
730 returns OK if the client should go ahead and prompt the user for more info,
731 or ERROR or ERROR+HIGHER_ACCESS_REQUIRED if the command will not succeed.
732 1 - Name for new room.
733 2 - Access type for new room:
735 1 - Private; can be entered by guessing the room's name
736 2 - Private; can be entered by knowing the name *and* password
737 3 - Private; invitation only (sometimes called "exclusive")
738 3 - Password for new room (if it is a type 2 room)
739 4 - Floor number on which the room should reside (optional)
741 If the create flag is set to 1, the room is created (unless something
742 went wrong and an ERROR return is sent), and the server returns OK, but
743 the session is **not** automatically sent to that room. The client still
744 must perform a GOTO command to go to the new room.
747 FORG (FORGet the current room)
749 This command is used to forget (zap) the current room. For those not
750 familiar with Citadel, this terminology refers to removing the room from
751 a user's own known rooms list, *not* removing the room itself. After a
752 room is forgotten, it no longer shows up in the user's known room list,
753 but it will exist in the user's forgotten room list, and will return to the
754 known room list if the user goes to the room (in Citadel, this is
755 accomplished by explicitly typing the room's name in a <.G>oto command).
757 The command takes no arguments. If the command cannot execute for any
758 reason, ERROR will be returned. ERROR+NOT_LOGGED_IN or ERROR+NOT_HERE may
759 be returned as they apply.
761 If the command succeeds, OK will be returned. At this point, the current
762 room is **undefined**, and the client software is responsible for taking
763 the user to another room before executing any other room commands (usually
764 this will be _BASEROOM_ since it is always there).
767 MESG (read system MESsaGe)
769 This command is used to display system messages and/or help files. The
770 single argument it accepts is the name of the file to display. IT IS CASE
771 SENSITIVE. Citadel/UX looks for these files first in the "messages"
772 subdirectory and then in the "help" subdirectory.
774 If the file is found, LISTING_FOLLOWS is returned, followed by a pathname
775 to the file being displayed. Then the message is printed, in format type 0
776 (see MSG0 command for more information on this). If the file is not found,
779 There are some "well known" names of system messages which client software
780 may expect most servers to carry:
782 hello - Welcome message, to be displayed before the user logs in.
783 changepw - To be displayed whenever the user is prompted for a new
784 password. Warns about picking guessable passwords and such.
785 register - Should be displayed prior to the user entering registration.
786 Warnings about not getting access if not registered, etc.
787 help - Main system help file.
788 goodbye - System logoff banner; display when user logs off.
789 roomaccess - Information about how public rooms and different types of
790 private rooms function with regards to access.
791 unlisted - Tells users not to choose to be unlisted unless they're
792 really paranoid, and warns that aides can still see
793 unlisted userlog entries.
795 Citadel/UX provides these for the Citadel/UX Unix text client. They are
796 probably not very useful for other clients:
798 mainmenu - Main menu (when in idiot mode).
803 saveopt - Options to save a message, abort, etc.
804 entermsg - Displayed just before a message is entered, when in
808 GNUR (Get Next Unvalidated User)
810 This command shows the name of a user that needs to be validated. If there
811 are no unvalidated users, OK is returned. Otherwise, MORE_DATA is returned
812 along with the name of the first unvalidated user the server finds. All of
813 the usual ERROR codes may be returned as well (for example, if the user is
814 not an Aide and cannot validate users).
816 A typical "Validate New Users" command would keep executing this command,
817 and then validating each user it returns, until it returns OK when all new
818 users have been validated.
821 GREG (Get REGistration for user)
823 This command retrieves the registration info for a user, whose name is the
824 command's sole argument. All the usual error messages can be returned. If
825 the command succeeds, LISTING_FOLLOWS is returned, followed by the user's name
826 (retrieved from the userlog, with the right upper and lower case etc.) The
827 contents of the listing contains one field per line, followed by the usual
828 000 on the last line.
830 The following lines are defined. Others WILL be added in the futre, so all
831 software should be written to read the lines it knows about and then ignore
837 Line 4: Street address or PO Box
838 Line 5: City/town/village/etc.
839 Line 6: State/province/etc.
841 Line 8: Telephone number
843 Line 10: Internet e-mail address
845 Users without Aide privileges may retrieve their own registration using
846 this command. This can be accomplished either by passing the user's own
847 name as the argument, or the string "_SELF_". The command will always
848 succeed when used in this manner, unless no user is logged in.
853 This command is used to validate users. Obviously, it can only be executed
854 by users with Aide level access. It should be passed two parameters: the
855 name of the user to validate, and the desired access level
857 If the command succeeds, OK is returned. The user's access level is changed
858 and the "need validation" bit is cleared. If the command fails for any
859 reason, ERROR, ERROR+NO_SUCH_USER, or ERROR+HIGHER_ACCESS_REQUIRED will be
863 EINF (Enter INFo file for room)
865 Transmit the info file for the current room with this command. EINF uses
866 a boolean flag (1 or 0 as the first and only argument to the command) to
867 determine whether the client actually wishes to transmit a new info file, or
868 is merely checking to see if it has permission to do so.
870 If the command cannot succeed, it returns ERROR.
871 If the client is only checking for permission, and permission will be
872 granted, OK is returned.
873 If the client wishes to transmit the new info file, SEND_LISTING is
874 returned, and the client should transmit the text of the info file, ended
875 by the usual 000 on a line by itself.
880 This is a simple user listing. It always succeeds, returning
881 LISTING_FOLLOWS followed by zero or more user records, 000 terminated. The
882 fields on each line are as follows:
887 4. Date/time of last login (Unix format)
890 7. Password (listed only if the user requesting the list is an Aide)
892 Unlisted entries will also be listed to Aides logged into the server, but
893 not to ordinary users.
896 REGI (send REGIstration)
898 Clients will use this command to transmit a user's registration info. If
899 no user is logged in, ERROR+NOT_LOGGED_IN is returned. Otherwise,
900 SEND_LISTING is returned, and the server will expect the following information
901 (terminated by 000 on a line by itself):
904 Line 2: Street address or PO Box
905 Line 3: City/town/village/etc.
906 Line 4: State/province/etc.
908 Line 6: Telephone number
909 Line 7: e-mail address
912 CHEK (CHEcK various things)
914 When logging in, there are various things that need to be checked. This
915 command will return ERROR+NOT_LOGGED_IN if no user is logged in. Otherwise
916 it returns OK and the following parameters:
918 0: Number of new private messages in Mail>
919 1: Nonzero if the user needs to register
920 2: (Relevant to Aides only) Nonzero if new users require validation
925 This command deletes a file from the room's directory, if there is one. The
926 name of the file to delete is the only parameter to be supplied. Wildcards
927 are not acceptable, and any slashes in the filename will be converted to
928 underscores, to prevent unauthorized access to neighboring directories. The
929 possible return codes are:
931 OK - Command succeeded. The file was deleted.
932 ERROR+NOT_LOGGED_IN - Not logged in.
933 ERROR+HIGHER_ACCESS_REQUIRED - Not an Aide or Room Aide.
934 ERROR+NOT_HERE - There is no directory in this room.
935 ERROR+FILE_NOT_FOUND - Requested file was not found.
940 This command is similar to DELF, except that it moves a file (and its
941 associated file description) to another room. It should be passed two
942 parameters: the name of the file to move, and the name of the room to move
943 the file to. All of the same return codes as DELF may be returned, and also
944 one additional one: ERROR+NO_SUCH_ROOM, which means that the target room
945 does not exist. ERROR+NOT_HERE could also mean that the target room does
946 not have a directory.
949 NETF (NETwork send a File)
951 This command is similar to MOVF, except that it attempts to send a file over
952 the network to another system. It should be passed two parameters: the name
953 of the file to send, and the node name of the system to send it to. All of
954 the same return codes as MOVF may be returned, except for ERROR+NO_SUCH_ROOM.
955 Instead, ERROR+NO_SUCH_SYSTEM may be returned if the name of the target
958 The name of the originating room will be sent along with the file. Most
959 implementations will look for a room with the same name at the receiving end
960 and attempt to place the file there, otherwise it goes into a bit bucket room
961 for miscellaneous files. This is, however, beyond the scope of this document;
962 see elsewhere for more details.
965 RWHO (Read WHO's online)
967 Displays a list of all users connected to the server. No error codes are
968 ever returned. LISTING_FOLLOWS will be returned, followed by zero or more
969 lines containing the following three fields:
971 0 - Session ID. Citadel/UX fills this with the pid of a server program.
973 2 - The name of the room the user is currently in. This field might not
974 be displayed (for example, if the user is in a private room) or it might
975 contain other information (such as the name of a file the user is
977 3 - (server v4.03 and above) The name of the host the client is connecting
978 from, or "localhost" if the client is local.
979 4 - (server v4.04 and above) Description of the client software being used
980 5 - The last time, locally to the server, that a command was received from
981 this client (Note: NOOP's don't count)
982 6 - The last command received from a client. (NOOP's don't count)
983 7 - Session flags. These are: + (spoofed address), - (STEALTH mode), *
984 (posting) and . (idle). (Citserver 5.02 and above)
986 The listing is terminated, as always, with the string "000" on a line by
990 OPEN (OPEN a file for download)
992 This command is used to open a file for downloading. Only one download
993 file may be open at a time. The only argument to this command is the name
994 of the file to be opened. The user should already be in the room where the
995 file resides. Possible return codes are:
998 ERROR+NOT_HERE (no directory in this room)
999 ERROR+FILE_NOT_FOUND (could not open the file)
1003 If the file is successfully opened, OK will be returned, along with the
1004 size (in bytes) of the file, and (in version 5.00 and above) the time of last
1008 CLOS (CLOSe the download file)
1010 This command is used to close the download file. It returns OK if the
1011 file was successfully closed, or ERROR if there wasn't any file open in the
1015 READ (READ from the download file)
1017 Two arguments are passed to this command. The first is the starting position
1018 in the download file, and the second is the total number of bytes to be
1019 read. If the operation can be performed, BINARY_FOLLOWS will be returned,
1020 along with the number of bytes to follow. Then, immediately following the
1021 newline, will be that many bytes of binary data. The client *must* read
1022 exactly that number of bytes, otherwise the client and server will get out
1025 If the operation cannot be performed, any of the usual error codes will be
1029 UOPN (OPeN a file for Uploading)
1031 This command is similar to OPEN, except that this one is used when the
1032 client wishes to upload a file to the server. The first argument is the name
1033 of the file to create, and the second argument is a one-line comment
1034 describing the contents of the file. Only one upload file may be open at a
1035 time. Possible return codes are:
1038 ERROR+NOT_HERE (no directory in this room)
1039 ERROR+FILE_NOT_FOUND (a name must be specified)
1040 ERROR (miscellaneous errors)
1041 ERROR+ALREADY_EXISTS (a file with the same name already exists)
1044 If OK is returned, the command has succeeded and writes may be performed.
1047 UCLS (CLoSe the Upload file)
1049 Close the file opened with UOPN. An argument of "1" should be passed to
1050 this command to close and save the file; otherwise, the transfer will be
1051 considered aborted and the file will be deleted. This command returns OK
1052 if the operation succeeded or ERROR if it did not.
1055 WRIT (WRITe to the upload file)
1057 If an upload file is open, this command may be used to write to it. The
1058 argument passed to this command is the number of bytes the client wishes to
1059 transmit. An ERROR code will be returned if the operation cannot be
1062 If the operation can be performed, SEND_BINARY will be returned, followed
1063 by the number of bytes the server is expecting. The client must then transmit
1064 exactly that number of bytes. Note that in the current implementation, the
1065 number of bytes the server is expecting will always be the number of bytes
1066 the client requested to transmit, but the client software should never assume
1067 that this will always happen, in case changes are made later.
1070 QUSR (Query for a USeR)
1072 This command is used to check to see if a particular user exists. The only
1073 argument to this command is the name of the user being searched for. If
1074 the user exists, OK is returned, along with the name of the user in the userlog
1075 (so the client software can learn the correct upper/lower casing of the name
1076 if necessary). If the user does not exist, ERROR+NO_SUCH_USER is returned.
1077 No login or current room is required to utilize this command.
1080 OIMG (Open an IMaGe file)
1082 Open an image (graphics) file for downloading. Once opened, the file can be
1083 read as if it were a download file. This implies that an image and a download
1084 cannot be opened at the same time. OIMG returns the same result codes as OPEN.
1086 All images will be in GIF (Graphics Interchange Format). In the case of
1087 Citadel/UX, the server will convert the supplied filename to all lower case,
1088 append the characters ".gif" to the filename, and look for it in the "images"
1089 subdirectory. As with the MESG command, there are several "well known"
1090 images which are likely to exist on most servers:
1092 hello - "Welcome" graphics to be displayed alongside MESG "hello"
1093 goodbye - Logoff banner graphics to be displayed alongside MESG "goodbye"
1094 background - Background image (usually tiled) for graphical clients
1096 The following "special" image names are defined in Citadel/UX server version
1099 _userpic_ - Picture of a user (send the username as the second argument)
1100 _floorpic_ - A graphical floor label (send the floor number as the second
1101 argument). Clients which request a floor picture will display
1102 the picture *instead* of the floor name.
1103 _roompic_ - A graphic associated with the *current* room. Clients which
1104 request a room picture will display the picture in *addition*
1105 to the room name (i.e. it's used for a room banner, as
1106 opposed to the floor picture's use in a floor listing).
1109 NETP (authenticate as network session with system NET Password)
1111 This command is used by client software to identify itself as a transport
1112 session for IGnet/Open BBS to BBS networking. It should be called with
1113 two arguments: the node name of the calling system, and the system net
1114 password for the server. If the authentication succeeds, NETP will return
1115 OK, otherwise, it returns ERROR.
1118 NUOP (Network Upload OPen file)
1120 Open a network spool file for uploading. The client must have already
1121 identified itself as a network session using the NETP command. If the command
1122 returns OK, the client may begin transmitting IGnet/Open spool data using
1123 a series of WRIT commands. When a UCLS command is issued, the spooled data
1124 is entered into the BBS if the argument to UCLS is 1 or discarded if the
1125 argument to UCLS is 0. If the client has not authenticated itself with a
1126 NETP command, ERROR+HIGHER_ACCESS_REQUIRED will be returned.
1129 NDOP (Network Download OPen file)
1131 Open a network spool file for downloading. The client must have already
1132 identified itself as a network session using the NETP command. If the command
1133 returns OK, the client may begin receiving IGnet/Open spool data using
1134 a series of READ commands. When a CLOS command is issued, the spooled data
1135 is deleted from the server and may not be read again. If the client has not
1136 authenticated itself with a NETP command, ERROR+HIGHER_ACCESS_REQUIRED will
1140 LFLR (List all known FLooRs)
1142 On systems supporting floors, this command lists all known floors. The
1143 command accepts no parameters. It will return ERROR+NOT_LOGGED_IN if no
1144 user is logged in. Otherwise it returns LISTING_FOLLOWS and a list of
1145 the available floors, each line consisting of three fields:
1147 1. The floor number associated with the floor
1148 2. The name of the floor
1149 3. Reference count (number of rooms on this floor)
1152 CFLR (Create a new FLooR)
1154 This command is used to create a new floor. It should be passed two
1155 arguments: the name of the new floor to be created, and a 1 or 0 depending
1156 on whether the client is actually creating a floor or merely checking to
1157 see if it has permission to create the floor. The user must be logged in
1158 and have Aide privileges to create a floor.
1160 If the command succeeds, it will return OK followed by the floor number
1161 associated with the new floor. Otherwise, it will return ERROR (plus perhaps
1162 HIGHER_ACCESS_REQUIRED, ALREADY_EXISTS, or INVALID_FLOOR_OPERATION)
1163 followed by a description of why the command failed.
1168 This command is used to delete a floor. It should be passed two
1169 argument: the *number* of the floor to be deleted, and a 1 or 0 depending
1170 on whether the client is actually deleting the floor or merely checking to
1171 see if it has permission to delete the floor. The user must be logged in
1172 and have Aide privileges to delete a floor.
1174 Floors that contain rooms may not be deleted. If there are rooms on a floor,
1175 they must be either deleted or moved to different floors first. This implies
1176 that the Main Floor (floor 0) can never be deleted, since Lobby>, Mail>, and
1177 Aide> all reside on the Main Floor and cannot be deleted.
1179 If the command succeeds, it will return OK. Otherwise it will return
1180 ERROR (plus perhaps HIGHER_ACCESS_REQUIRED or INVALID_FLOOR_OPERATION)
1181 followed by a description of why the command failed.
1186 Edit the parameters of a floor. The client may pass one or more parameters
1189 1. The number of the floor to be edited
1190 2. The desired new name
1192 More parameters may be added in the future. Any parameters not passed to
1193 the server will remain unchanged. A minimal command would be EFLR and a
1194 floor number -- which would do nothing. EFLR plus the floor number plus a
1195 floor name would change the floor's name.
1197 If the command succeeds, it will return OK. Otherwise it will return
1198 ERROR (plus perhaps HIGHER_ACCESS_REQUIRED or INVALID_FLOOR_OPERATION)
1201 IDEN (IDENtify the client software)
1203 The client software has the option to identify itself to the server.
1204 Currently, the server does nothing with this information except to write
1205 it to the syslog to satisfy the system administrator's curiosity. Other
1206 uses might become apparent in the future.
1208 The IDEN command should contain five fields: a developer ID number (same as
1209 the server developer ID numbers in the INFO command -- please obtain one if
1210 you are a new developer), a client ID number (which does not have to be
1211 globally unique - only unique within the domain of the developer number),
1212 a version number, a free-form text string describing the client, and the name
1213 of the host the user is located at.
1215 It is up to the server to determine whether to accept the host name or to
1216 use the host name it has detected itself. Generally, if the client is
1217 running on a trusted host (either localhost or a well-known publically
1218 accessible client) it should use the host name transmitted by IDEN,
1219 otherwise it should use the host name it has detected itself.
1221 IDEN always returns OK, but since that's the only way it ever returns
1222 there's no point in checking the result code.
1225 IPGM (identify as an Internal ProGraM)
1227 IPGM is a low-level command that should not be used by normal user clients.
1228 It is used for various utilities to communicate with the server on the same
1229 host. For example, the networker (netproc.c) logs onto the server as an
1230 internal program in order to fetch and store messages. Since user clients
1231 do not utilize this command (or any of its companion commands), developers
1232 writing Citadel-compatible servers need not implement it.
1234 The sole argument to IPGM is the system's internal program password. This
1235 password is generated by the setup program and stored in the config file.
1236 Since internal programs have access to the config file, they know the correct
1239 IPGM returns OK for a correct authentication or ERROR otherwise.
1242 CHAT (enter CHAT mode)
1244 This command functions differently from every other command in the system. It
1245 is used to implement multi-user chat. For this to function, a new transfer
1246 mode, called START_CHAT_MODE, is implemented. If a client does not support
1247 chat mode, it should never send a CHAT command!
1249 In chat mode, messages may arrive asynchronously from the server at any
1250 time. The client may send messages at any time. This allows the arrival of
1251 messages without the client having to poll for them. Arriving messages will
1252 be of the form "user|message", where the "user" portion is, of course, the
1253 name of the user sending the message, and "message" is the message text.
1255 Chat mode ends when the server says it ends. The server will signal the end
1256 of chat mode by transmitting "000" on a line by itself. When the client reads
1257 this line, it must immediately exit from chat mode without sending any
1258 further traffic to the server. The next transmission sent to the server
1259 will be a regular server command.
1261 The Citadel/UX server understands the following commands:
1262 /quit - Exit from chat mode (causes the server to do an 000 end)
1263 /who - List users currently in chat
1264 /whobbs - List users currently in chat and on the bbs
1265 /me - Do an irc-style action.
1266 /join - Join a new "room" in which all messages are only heard by
1267 people in that room.
1268 /msg - /msg <user> <msg> will send the msg to <user> only.
1269 /help - Print help information
1270 NOOP - Do nothing (silently)
1272 Any other non-empty string is treated as message text and will be broadcast
1273 to other users currently in chat.
1276 SEXP (Send EXPress messages)
1278 This is one of two commands which implement "express messages" (also known
1279 as "paging"). An express message is a near-real-time message sent from one
1280 logged in user to another. When an express message is sent, it will be
1281 displayed the next time the target user executes a PEXP command.
1283 The SEXP command accepts two arguments: the name of the user to send the
1284 message to, and the text of the message. If the message is successfully
1285 transmitted, OK is returned. If the target user is not logged in or if
1286 anything else goes wrong, ERROR is returned.
1288 If the server supports extended paging, sending a zero-length message
1289 merely checks for the presence of the requested user without actually sending
1290 a message. Sending a message consisting solely of a "-" (hyphen) will cause
1291 the server to return SEND_LISTING if the requested user is logged in, and the
1292 client can then transmit a multi-line page.
1294 The reserved name "broadcast" may be used instead of a user name, to
1295 broadcast an express message to all users currently connected to the server.
1297 Do be aware that if an express message is transmitted to a user who is logged
1298 in using a client that does not check for express messages, the message will
1302 PEXP (Print EXPress messages)
1304 This command, called without any arguments, simply dumps out the contents
1305 of any waiting express messages. It returns ERROR if there is a problem,
1306 otherwise it returns LISTING_FOLLOWS followed by all messages.
1308 So how does the client know there are express messages waiting? It could
1309 execute a random PEXP every now and then. Or, it can check the byte in
1310 server return code messages, between the return code and the parameters. In
1311 much the same way as FTP uses "-" to signify a continuation, Citadel uses
1312 an "*" in this position to signify the presence of waiting express messages.
1315 EBIO (Enter BIOgraphy)
1317 Transmit to the server a free-form text file containing a little bit of
1318 information about the user for other users to browse. This is typically
1319 referred to as a 'bio' online. EBIO returns SEND_LISTING if it succeeds,
1320 after which the client is expected to transmit the file, or any of the usual
1321 ERROR codes if it fails.
1324 RBIO (Read BIOgraphy)
1326 Receive from the server a named user's bio. This command should be passed
1327 a single argument - the name of the user whose bio is requested. RBIO returns
1328 LISTING_FOLLOWS plus the bio file if the user exists and has a bio on file,
1329 ERROR+NO_SUCH_USER if the named user does not exist, or ERROR+FILE_NOT_FOUND
1330 if the user exists but has no bio on file.
1333 STEL (enter STEaLth mode)
1335 When in "stealth mode," a user will not show up in the "Who is online"
1336 listing (the RWHO server command). Only Aides may use stealth mode. The
1337 STEL command accepts one argument: a 1 indicating that the user wishes to
1338 enter stealth mode, or a 0 indicating that the user wishes to exit stealth
1339 mode. STEL returns OK if the command succeeded, ERROR+NOT_LOGGED_IN if no
1340 user is logged in, or ERROR+HIGHER_ACCESS_REQUIRED if the user is not an Aide.
1342 The STEL command also makes it so a user does not show up in the chat room
1346 LBIO (List users who have BIOs on file)
1348 This command is self-explanatory. Any user who has used EBIO to place a bio
1349 on file is listed. LBIO almost always returns LISTING_FOLLOWS followed by
1350 this listing, unless it experiences an internal error in which case ERROR
1354 MSG2 (read MeSsaGe, mode 2)
1356 MSG2 follows the same calling convention as MSG0. The difference between
1357 the two commands is that MSG2 outputs messages in standard RFC822 format
1358 rather than in Citadel/UX proprietary format.
1360 This command was implemented in order to make various gateway programs
1361 easier to implement, and to provide some sort of multimedia support in the
1362 future. Keep in mind that when this command is used, all messages will be
1363 output in fixed 80-column format.
1366 MSG3 (read MeSsaGe, mode 3 -- internal command)
1368 MSG3 is for use by internal programs only and should not be utilized by
1369 user-mode clients. It does require IPGM authentication. MSG3 follows the
1370 same calling convention as the other MSG commands, but upon success returns
1371 BINARY_FOLLOWS followed by a data block containing the _raw_ message format
1375 ENT3 (ENTer message, mode 3 -- internal command)
1377 ENT3 is for use by internal programs only and should not be utilized by
1378 user-mode clients. It does require IPGM authentication. This command posts
1379 a raw message straight into the message base without modification or performing
1380 any checks. It accepts the following arguments:
1382 0 - Post flag. This should be set to 1 to post a message. If it is
1383 set to 0, the server only returns OK or ERROR (plus any flags describing
1384 the error) without reading in a message. This is used to verify the operation
1385 before actually transmitting a message.
1386 1 - Recipient. This argument is utilized only for private mail messages.
1387 It is ignored for public messages. It contains, of course, the name of the
1388 recipient of the message.
1389 2 - The size (in bytes) of the message to be transmitted.
1391 ENT3 returns OK to tell the client that a message can be posted, ERROR if
1392 there would be a problem with the operation, or SEND_BINARY followed by a byte
1393 count if it is expecting the message to be transmitted.
1396 TERM (TERMinate another session)
1398 In a multithreaded environment, it sometimes becomes necessary to terminate
1399 a session that is unusable for whatever reason. The TERM command performs
1400 this task. Naturally, only Aides can execute TERM. The command should be
1401 called with a single argument: the session ID (obtained from an RWHO command)
1402 of the session to be terminated.
1404 TERM returns OK if the session was terminated, or ERROR otherwise. Note that
1405 a client program is prohibited from terminating the session it is currently
1409 NSET (Network SETup commands)
1411 Aides may use this command to configure the networker. This command's
1412 parameters are passed directly to the 'netsetup' command line utility. If
1413 netsetup returns a non-zero exit code, ERROR is returned, along with the
1414 error message (if any). If netsetup returns a zero (success) exit code,
1415 LISTING_FOLLOWS is returned, followed by zero or more lines of output (since
1416 netsetup may have information to display, such as a room or node list) and
1417 the usual '000' listing terminator.
1420 DOWN (shut DOWN the server)
1422 This command, which may only be executed by an Aide, immediately shuts down
1423 the server. It is only implemented on servers on which such an operation is
1424 possible, such as a multithreaded Citadel engine. The server does not restart.
1425 DOWN returns OK if the user is allowed to shut down the server, in which case
1426 the client program should expect the connection to be immediately broken.
1429 SCDN (Schedule or Cancel a shutDowN)
1431 SCDN sets or clears the "scheduled shutdown" flag. Pass this command a 1 or
1432 0 to respectively set or clear the flag. When the "scheduled shutdown" flag is
1433 set, the server will be shut down when there are no longer any users logged in.
1434 Any value other than 0 or 1 will not change the flag, only report its state.
1435 No users will be kicked off the system, and in fact the server is still available
1436 for new connections. The command returns ERROR if it fails; otherwise, it
1437 returns OK followed by a number representing the current state of the flag.
1440 EMSG (Enter a system MeSsaGe)
1442 This is the opposite of the MESG command - it allows the creation and editing
1443 of system messages. The only argument passed to EMSG is the name of the
1444 file being transmitted. If the file exists in any system message directory
1445 on the server it will be overwritten, otherwise a new file is created. EMSG
1446 returns SEND_LISTING on success or ERROR+HIGHER_ACCESS_REQUIRED if the user
1449 Typical client software would use MESG to retrieve any existing message into
1450 an edit buffer, then present an editor to the user and run EMSG if the changes
1454 UIMG (Upload an IMaGe file)
1456 UIMG is complemenary to OIMG; it is used to upload an image to the server.
1457 The first parameter supplied to UIMG should be 0 if the client is only checking
1458 for permission to upload, or 1 if the client is actually attempting to begin
1459 the upload operation. The second argument is the name of the file to be
1460 transmitted. In Citadel/UX, the filename is converted to all lower case,
1461 appended with the characters ".gif", and stored in the "images" directory.
1463 UIMG returns OK if the client has permission to perform the requested upload,
1464 or ERROR+HIGHER_ACCESS_REQUIRED otherwise. If the client requested to begin
1465 the operation (first parameter set to 1), an upload file is opened, and the
1466 client should begin writing to it with WRIT commands, then close it with a
1469 The supplied filename should be one of:
1471 -> _userpic_ (Server will attempt to write to the user's online photo)
1472 -> Any of the "well known" filenames described in the writeup for the
1475 ----------------------------------------------
1476 The following are for citserver 5.02 and above
1477 ----------------------------------------------
1479 HCHG (Hostname CHanGe)
1481 HCHG is a command, usable by any user, that allows a user to change their RWHO
1482 host value. This will mask a client's originating hostname from normal
1483 users; access level 6 and higher see an entry right underneath the spoofed
1484 entry listing the actual hostname the user originates from.
1486 The format of an HCHG command is:
1490 If a HCHG command is successful, the value OK (200) is returned.
1493 RCHG (Roomname CHanGe)
1495 RCHG is a command, usable by any user, that allows a user to change their RWHO
1496 room value. This will mask a client's roomname from normal users; access
1497 level 6 and higher see an entry right underneath the spoofed entry listing
1498 the actual room the user is in.
1500 The format of an RCHG command is:
1504 If a RCHG command is successful, the value OK (200) is returned.
1507 UCHG (Username CHanGe)
1509 UCHG is an aide-level command which allows an aide to effectively change their
1510 username. If this value is blank, the user goes into stealth mode (see
1512 will show up as being from the real username in this mode, however. In
1513 addition, the RWHO listing will include both the spoofed and real usernames.
1515 The format of an UCHG command is:
1519 If a UCHG command is successful, the value OK (200) is returned.
1522 TIME (get server local TIME)
1524 TIME returns OK followed by the current time measured in seconds since
1525 00:00:00 GMT, Jan 1, 1970 (standard Unix format).
1527 This is used in allowing a client to calculate idle times.
1530 AGUP (Administrative Get User Parameters)
1531 ASUP (Administrative Set User Parameters)
1533 These commands are only executable by Aides and by server extensions running
1534 at system-level. They are used to get/set any and all parameters relating to
1535 a user account. AGUP requires only one argument: the name of the user in
1536 question. SGUP requires all of the parameters to be set. The parameters are
1537 as follows, and are common to both commands:
1541 2 - Flags (see citadel.h)
1546 7 - Timestamp of last call
1547 8 - Purge time (in days) for this user (or 0 to use system default)
1549 Upon success, AGUP returns OK followed by all these parameters, and ASUP
1550 simply returns OK. If the client has insufficient access to perform the
1551 requested operation, ERROR+HIGHER_ACCESS_REQUIRED is returned. If the
1552 requested user does not exist, ERROR+NO_SUCH_USER is returned.
1556 GPEX (Get Policy for message EXpiration)
1558 Returns the policy of the current room, floor, or site regarding the automatic
1559 purging (expiration) of messages. The following policies are available:
1560 0 - Fall back to the policy of the next higher level. If this is a room,
1561 use the floor's default policy. If this is a floor, use the system
1562 default policy. This is an invalid value for the system policy.
1563 1 - Do not purge messages automatically.
1564 2 - Purge by message count. (Requires a value: number of messages)
1565 3 - Purge by message age. (Requires a value: number of days)
1567 The format of this command is: GPEX <which>
1568 The value of <which> must be one of: "room" "floor" "site"
1570 If successful, GPEX returns OK followed by <policy>|<value>.
1574 SPEX (Set Polict for message EXpiration)
1576 Sets the policy of the current room, floor, or site regarding the automatic
1577 purging (expiration) of messages. See the writeup for the GPEX command for
1578 the list of available policies.
1580 The format of this command is: SPEX <which>|<policy>|<value>
1581 The value of <which> must be one of: "room" "floor" "site"
1583 If successful, GPEX returns OK; otherwise, an ERROR code is returned.
1587 CONF (get or set global CONFiguration options)
1589 Retrieves or sets various system-wide configuration and policy options. This
1590 command is only available to Aides. The sole parameter accepted is a command,
1591 which should be either GET or SET. If the GET command succeeds, CONF will
1592 return LISTING_FOLLOWS followed by the fields described below, one line at a
1593 time. If the SET command succeeds, CONF will return SEND_LISTING and expect
1594 the fields described below, one line at a time (don't worry about other fields
1595 being added in the future; if a 'short' configuration list is sent, the missing
1596 values at the end will be left unchanged on the system). If either command
1597 fails for any reason, ERROR is returned.
1599 The configuration lines are as follows:
1602 2. Fully qualified domain name
1603 3. Human-readable node name
1604 4. Landline telephone number of this system
1605 5. Flag (0 or 1) - creator of private room automatically becomes room aide
1606 6. Server connection idle timeout (in seconds)
1607 7. Initial access level for new users
1608 8. Flag (0 or 1) - require registration for new users
1609 9. Flag (0 or 1) - automatically move Problem User messages to twit room
1610 10. Name of twit room
1611 11. Text of <more> prompt
1612 12. Flag (0 or 1) - restrict access to Internet mail
1613 13. Geographic location of this system
1614 14. Name of the system administrator
1615 15. Number of maximum concurrent sessions allowed on the server
1616 16. Password for server-to-server networking
1617 17. Default purge time (in days) for users
1618 18. Default purge time (in days) for rooms
1619 19. Name of room to log express messages to (or a zero-length name for none)
1623 EXPI (EXPIre system objects)
1625 Begins purge operations for objects which, according to site policy, are
1626 "old" and should be removed. EXPI should be called with one argument, one of:
1628 "messages" (purge old messages out of each room)
1629 "users" (purge old users from the userlog)
1630 "rooms" (remove rooms which have not been posted in for some time)
1631 "visits" (purge dereferenced user/room relationship records)
1633 EXPI returns OK (probably after a long delay while it does its work) if it
1634 succeeds; otherwise it returns an ERROR code.
1636 This command is probably temporary, until we can work some sort of scheduler
1637 into the system. It is implemented in the serv_expire module.