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 Version 4.01 and above only:
221 Starting with version 4.01 and above, floors are supported. The first
222 argument to LKRN should be the number of the floor to list rooms from. Only
223 rooms from this floor will be listed. If no arguments are passed to LKRN, or
224 if the floor number requested is (-1), rooms on all floors will be listed.
226 The third field displayed on each line is the number of the floor the room
227 is on. The LFLR command should be used to associate floor numbers with
232 LKRO (List Known Rooms with Old [no new] messages)
234 This follows the same usage and format as LKRN.
237 LZRM (List Zapped RooMs)
239 This follows the same usage and format as LKRN and LKRO.
242 LKRA (List All Known Rooms)
244 Same format. Lists all known rooms, with or without new messages.
247 LRMS (List all accessible RooMS)
249 Again, same format. This command lists all accessible rooms, known and
250 forgotten, with and without new messages. It does not, however, list
251 inaccessible private rooms.
254 GETU (GET User configuration)
256 This command retrieves the screen dimensions and user options for the
257 currently logged in account. ERROR will be returned if no user is logged
258 in, of course. Otherwise, OK will be returned, followed by three parameters.
259 The first parameter is the user's screen width, the second parameter is the
260 user's screen height, and the third parameter is a bag of bits with the
263 #define US_LASTOLD 16 /* Print last old message with new */
264 #define US_EXPERT 32 /* Experienced user */
265 #define US_UNLISTED 64 /* Unlisted userlog entry */
266 #define US_NOPROMPT 128 /* Don't prompt after each message */
267 #define US_DISAPPEAR 512 /* Use "disappearing msg prompts" */
268 #define US_PAGINATOR 2048 /* Pause after each screen of text */
270 There are other bits, too, but they can't be changed by the user (see below).
273 SETU (SET User configuration)
275 This command does the opposite of SETU: it takes the screen dimensions and
276 user options (which were probably obtained with a GETU command, and perhaps
277 modified by the user) and writes them to the user account. This command
278 should be passed three parameters: the screen width, the screen height, and
279 the option bits (see above).
281 Note that there exist bits here which are not listed in this document. Some
282 are flags that can only be set by Aides or the system administrator. SETU
283 will ignore attempts to toggle these bits. There also may be more user
284 settable bits added at a later date. To maintain later downward compatibility,
285 the following procedure is suggested:
287 1. Execute GETU to read the current flags
288 2. Toggle the bits that we know we can toggle
289 3. Execute SETU to write the flags
291 If we are passed a bit whose meaning we don't know, it's best to leave it
292 alone, and pass it right back to the server. That way we can use an old
293 client on a server that uses an unknown bit without accidentally clearing
294 it every time we set the user's configuration.
299 This command is used to goto a new room. When the user first logs in (login
300 is completed after execution of the PASS command) this command is
301 automatically and silently executed to take the user to the first room in the
302 system (usually called the Lobby).
304 This command can be passed one or two parameters. The first parameter is,
305 of course, the name of the room. Although it is not case sensitive, the
306 full name of the room must be used. Wildcard matching or unique string
307 matching of room names should be the responsibility of the client.
309 Note that the reserved room name "_BASEROOM_" can be passed to the server
310 to cause the goto command to take the user to the first room in the system,
311 traditionally known as the Lobby>. As long as a user is logged in, a
312 GOTO command to _BASEROOM_ is guaranteed to succeed. This is useful to
313 allow client software to return to the base room when it doesn't know
316 There are also two additional reserved room names:
317 "_MAIL_" translates to the system's designated room for e-mail messages.
318 "_BITBUCKET_" goes to whatever room has been chosen for messages
321 The second (and optional) parameter is a password, if one is required for
322 access to the room. This allows for all types of rooms to be accessed via
323 this command: for public rooms, invitation-only rooms to which the user
324 has access, and preferred users only rooms to which the user has access, the
325 room will appear in a room listing. For guess-name rooms, this command
326 will work transparently, adding the room to the user's known room list when
327 it completes. For passworded rooms, access will be denied if the password
328 is not supplied or is incorrect, or the command will complete successfully
329 if the password is correct.
331 The possible result codes are:
333 OK - The command completed successfully. User is now in the room.
334 (See the list of returned parameters below)
336 ERROR - The command did not complete successfully. Check the second and
337 third positions of the result code to find out what happened:
339 NOT_LOGGED_IN - Of course you can't go there. You didn't log in.
340 PASSWORD_REQUIRED - Either a password was not supplied, or the supplied
341 password was incorrect.
342 NO_SUCH_ROOM - The requested room does not exist.
344 The typical procedure for entering a passworded room would be:
346 1. Execute a GOTO command without supplying any password.
347 2. ERROR+PASSWORD_REQUIRED will be returned. The client now knows that
348 the room is passworded, and prompts the user for a password.
349 3. Execute a GOTO command, supplying both the room name and the password.
350 4. If OK is returned, the command is complete. If, however,
351 ERROR+PASSWORD_REQUIRED is still returned, tell the user that the supplied
352 password was incorrect. The user remains in the room he/she was previously
355 When the command succeeds, these parameters are returned:
356 0. The name of the room
357 1. Number of unread messages in this room
358 2. Total number of messages in this room
359 3. Info flag: set to nonzero if the user needs to read this room's info
360 file (see RINF command below)
361 4. Various flags associated with this room. (See LKRN cmd above)
362 5. The highest message number present in this room
363 6. The highest message number the user has read in this room
364 7. Boolean flag: 1 if this is a Mail> room, 0 otherwise.
365 8. Aide flag: 1 if the user is either the Room Aide for this room, *or* is
366 a regular Aide (this makes access checks easy).
367 9. The number of new Mail messages the user has (useful for alerting the
368 user to the arrival of new mail during a session)
369 10. The floor number this room resides on
372 MSGS (get pointers to MeSsaGeS in this room)
374 This command obtains a listing of all the messages in the current room
375 which the client may request. This command may be passed a single parameter:
376 either "all", "old", or "new" to request all messages, only old messages, or
377 new messages. Or it may be passed two parameters: "last" plus a number, in which
378 case that many message pointers will be returned, or "first" plus a number, for
379 the corresponding effect. If no parameters are specified, "all" is assumed.
381 In Citadel/UX 5.00 and above, the client may also specify "gt" plus a number, to
382 list all messages in the current room with a message number greater than the one
385 This command can return two possible results. An ERROR code may be returned
386 if no user is currently logged in or if something else went wrong. Otherwise,
387 LISTING_FOLLOWS will be returned, and the listing will consist of zero or
388 more message numbers, one per line. The listing ends, as always, with the
389 string "000" alone on a line by itself. The listed message numbers can be used
390 to request messages from the system.
393 MSG0 (read MeSsaGe, mode 0)
395 This is a command used to read the text of a message. "Mode 0" implies that
396 other MSG commands (MSG1, MSG2, etc.) will probably be added later on to read
397 messages in more robust formats. This command should be passed two arguments.
398 The first is the message number of the message being requested. In server
399 version 4.04 and above, the second argument may be set to either 0 to read the
400 entire message, or 1 to read the headers only.
402 The server should, of course, make sure that the client actually has access
403 to the message being requested before honoring this request. Citadel/UX does
404 so by checking the message number against the contents of the current room. If
405 it's not there, the request is denied.
407 If the request is denied, an ERROR code will be returned. Otherwise, the
408 LISTING_FOLLOWS code will be returned, followed by the contents of the message.
409 The following fields may be sent:
411 type= Formatting type. Currently, there are two defined types. Type 0 is
412 "traditional" Citadel formatting. This means that newlines should be treated
413 as spaces UNLESS the first character on the next line is a space. In other
414 words, only indented lines should generate a newline on the user's screen when
415 the message is being displayed. This allows a message to be formatted to the
416 reader's screen width. It also allows the use of proportional fonts.
417 Type 1 is a simple fixed-format message. The message should be displayed to
418 the user's screen as is, preferably in a fixed-width font that will fit 80
421 msgn= The message ID of this message on the system it originated on.
422 path= An e-mailable path back to the user who wrote the message.
424 time= The date and time of the message, in Unix format (the number of
425 seconds since midnight on January 1, 1970, GMT).
427 from= The name of the author of the message.
428 rcpt= If the message is a private e-mail, this is the recipient.
429 room= The name of the room the message originated in.
430 node= The short node name of the system this message originated on.
431 hnod= The long node name of the system this message originated on.
433 text Note that there is no "=" after the word "text". This string
434 signifies that the message text begins on the next line.
437 WHOK (WHO Knows room)
439 This command is available only to Aides. ERROR+HIGHER_ACCESS_REQUIRED will
440 be returned if the user is not an Aide. Otherwise, it returns
441 LISTING_FOLLOWS and then lists, one user per line, every user who has
442 access to the current room.
445 INFO (get server INFO)
447 This command will *always* return LISTING_FOLLOWS and then print out a
448 listing of zero or more strings. Client software should be written to expect
449 anywhere from a null listing to an infinite number of lines, to allow later
450 backward compatibility. The current implementation defines the following
451 parts of the listing:
453 Line 1 - Your unique session ID on the server
454 Line 2 - The node name of the server BBS
455 Line 3 - Human-readable node name of the server BBS
456 Line 4 - The fully-qualified domain name (FQDN) of the server
457 Line 5 - The name of the server software, i.e. "Citadel/UX 4.00"
458 Line 6 - (The revision level of the server code) * 100
459 Line 7 - The geographical location of the BBS (for USA: city and state)
460 Line 8 - The name of the system administrator
461 Line 9 - A number identifying the server type (see below)
462 Line 10 - The text of the system's paginator prompt
463 Line 11 - Floor Flag. 1 if the system supports floors, 0 otherwise.
465 *** NOTE! *** The "server type" code is intended to promote global
466 compatibility in a scenario in which developers have added proprietary
467 features to their servers or clients. We are attempting to avoid a future
468 situation in which users need to keep different client software around for
469 each BBS they use. *Please*, if you are a developer and plan to add
470 proprietary features:
472 -> Your client programs should still be able to utilize servers other than
474 -> Clients other than your own should still be able to utilize your server,
475 even if your proprietary extensions aren't supported.
476 -> Please contact Art Cancro <ajc@uncnsrd.mt-kisco.ny.us> and obtain a unique
477 server type code, which can be assigned to your server program.
478 -> If you document what you did in detail, perhaps it can be added to a
479 future release of the Citadel/UX program, so everyone can enjoy it. Better
480 yet, just work with the Citadel development team on the main source tree.
482 If everyone follows this scheme, we can avoid a chaotic situation with lots
483 of confusion about which client program works with which server, etc. Client
484 software can simply check the server type (and perhaps the revision level)
485 to determine ahead of time what commands may be utilized.
487 Please refer to "developers.txt" for information on what codes belong to whom.
491 RDIR (Read room DIRectory)
493 Use this command to read the directory of a directory room. ERROR+NOT_HERE
494 will be returned if the room has no directory, or some other error; ERROR +
495 HIGHER_ACCESS_REQUIRED will be returned if the room's directory is not
496 visible and the user does not have Aide or Room Aide privileges; otherwise
497 LISTING_FOLLOWS will be returned, followed by the room's directory. Each
498 line of the directory listing will contain three fields: a filename, the
499 length of the file, and a description.
501 The server message contained on the same line with LISTING_FOLLOWS will
502 contain the name of the system and the name of the directory, such as:
503 uncnsrd.mt-kisco.ny.us|/usr/bbs/files/my_room_directory
506 SLRP (Set Last-message-Read Pointer)
508 This command is used to mark messages as having been read. Its sole parameter
509 is the number of the last message that has been read. This allows the pointer
510 to be set at any arbitrary point in the room. Optionally, the parameter
511 "highest" may be used instead of a message number, to set the pointer to the
512 number of the highest message in the room, effectively marking all messages
513 in the room as having been read (ala the Citadel <G>oto command).
515 The command will return OK if the pointer was set, or ERROR if something
516 went wrong. If OK is returned, it will be followed by a single argument
517 containing the message number the last-read-pointer was set to.
520 INVT (INViTe a user to a room)
522 This command may only be executed by Aides, or by the room aide for the
523 current room. It is used primarily to add users to invitation-only rooms,
524 but it may also be used in other types of private rooms as well. Its sole
525 parameter is the name of the user to invite.
527 The command will return OK if the operation succeeded, or ERROR if it did
528 not. ERROR+HIGHER_ACCESS_REQUIRED may also be returned if the operation
529 would have been possible if the user had higher access, and ERROR+NOT_HERE
530 may be returned if the room is not a private room.
533 KICK (KICK a user out of a room)
535 This is the opposite of INVT: it is used to kick a user out of a private
536 room. It can also be used to kick a user out of a public room, but the
537 effect will only be the same as if the user <Z>apped the room - a non-stupid
538 user can simply un-zap the room to get back in.
541 GETR (GET Room attributes)
543 This command is used for editing the various attributes associated with a
544 room. A typical "edit room" command would work like this:
545 1. Use the GETR command to get the current attributes
546 2. Change some of them around
547 3. Use SETR (see below) to save the changes
548 4. Possibly also change the room aide using the GETA and SETA commands
550 GETR takes no arguments. It will only return OK if the SETR command will
551 also return OK. This allows client software to tell the user that he/she
552 can't edit the room *before* going through the trouble of actually doing the
553 editing. Possible return codes are:
555 ERROR+NOT_LOGGED_IN - No user is logged in.
556 ERROR+HIGHER_ACCESS_REQUIRED - Not enough access. Typically, only aides
557 and the room aide associated with the current room, can access this command.
558 ERROR+NOT_HERE - Lobby>, Mail>, and Aide> cannot be edited.
559 OK - Command succeeded. Parameters are returned.
561 If OK is returned, the following parameters will be returned as well:
563 0. The name of the room
564 1. The room's password (if it's a passworded room)
565 2. The name of the room's directory (if it's a directory room)
566 3. Various flags (bits) associated with the room (see LKRN cmd above)
567 4. The floor number on which the room resides
570 SETR (SET Room attributes)
572 This command sets various attributes associated with the current room. It
573 should be passed the following arguments:
575 0. The name of the room
576 1. The room's password (if it's a passworded room)
577 2. The name of the room's directory (if it's a directory room)
578 3. Various flags (bits) associated with the room (see LKRN cmd above)
579 4. "Bump" flag (see below)
580 5. The floor number on which the room should reside
582 *Important: You should always use GETR to retrieve the current attributes of
583 the room, then change what you want to change, and then use SETR to write it
584 all back. This is particularly important with respect to the flags: if a
585 particular bit is set, and you don't know what it means, LEAVE IT ALONE and
586 only toggle the bits you want to toggle. This will allow for upward
589 If the room is a private room, you have the option of causing all users who
590 currently have access, to forget the room. If you want to do this, set the
591 "bump" flag to 1, otherwise set it to 0.
596 This command is used to get the name of the Room Aide for the current room.
597 It will return ERROR+NOT_LOGGED_IN if no user is logged in, ERROR if there
598 is no current room, or OK if the command succeeded. Along with OK there will
599 be returned one parameter: the name of the Room Aide.
604 The opposite of GETA, used to set the Room Aide for the current room. One
605 parameter should be passed, which is the name of the user who is to be the
606 new Room Aide. Under Citadel/UX, this command may only be executed by Aides
607 and by the *current* Room Aide for the room. Return codes possible are:
608 ERROR+NOT_LOGGED_IN (Not logged in.)
609 ERROR+HIGHER_ACCESS_REQUIRED (Higher access required.)
610 ERROR+NOT_HERE (No current room, or room cannot be edited.
611 Under Citadel/UX, the Lobby> Mail> and Aide> rooms are non-editable.)
612 OK (Command succeeded.)
615 ENT0 (ENTer message, mode 0)
617 This command is used to enter messages into the system. It accepts four
620 0 - Post flag. This should be set to 1 to post a message. If it is
621 set to 0, the server only returns OK or ERROR (plus any flags describing
622 the error) without reading in a message. Client software should, in fact,
623 perform this operation at the beginning of an "enter message" command
624 *before* starting up its editor, so the user does not end up typing a message
625 in vain that will not be permitted to be saved. If it is set to 2, the
626 server will accept an "apparent" post name if the user is privileged enough.
627 This post name is arg 4.
628 1 - Recipient. This argument is utilized only for private mail messages.
629 It is ignored for public messages. It contains, of course, the name of the
630 recipient of the message.
631 2 - Anonymous flag. This argument is ignored unless the room allows
632 anonymous messages. In such rooms, this flag may be set to 1 to flag a
633 message as anonymous, otherwise 0 for a normal message.
634 3 - Format type. Any valid Citadel/UX format type may be used (this will
635 typically be 0; see the MSG0 command above).
636 4 - Post name. When postflag is 2, this is the name you are posting as.
637 This is an Aide only command.
639 Possible result codes:
640 OK - The request is valid. (Client did not set the "post" flag, so the
641 server will not read in message text.) If the message is an e-mail with
642 a recipient, the text that follows the OK code will contain the exact name
643 to which mail is being sent. The client can display this to the user. The
644 implication here is that the name that the server returns will contain the
645 correct upper and lower case characters. In addition, if the recipient is
646 having his/her mail forwarded, the forwarding address will be returned.
647 SEND_LISTING - The request is valid. The client should now transmit
648 the text of the message (ending with a 000 on a line by itself, as usual).
649 ERROR - Miscellaneous error. (Explanation probably follows.)
650 ERROR + NOT_LOGGED_IN - Not logged in.
651 ERROR + HIGHER_ACCESS_REQUIRED - Higher access is required. An
652 explanation follows, worded in a form that can be displayed to the user.
653 ERROR + NO_SUCH_USER - The specified recipient does not exist.
656 RINF (read Room INFormation file)
658 Each room has associated with it a text file containing a description of
659 the room, perhaps containing its intended purpose or other important
660 information. The info file for the Lobby> (the system's base room) is
661 often used as a repository for system bulletins and the like.
663 This command, which accepts no arguments, is simply used to read the info
664 file for the current room. It will return LISTING_FOLLOWS followed by
665 the text of the message (always in format type 0) if the request can be
666 honored, or ERROR if no info file exists for the current room (which is
667 often the case). Other error description codes may accompany this result.
669 When should this command be used? This is, of course, up to the discretion
670 of client software authors, but in Citadel it is executed in two situations:
671 the first time the user ever enters a room; and whenever the contents of the
672 file change. The latter can be determined from the result of a GOTO command,
673 which will tell the client whether the file needs to be read (see GOTO above).
676 DELE (DELEte a message)
678 Delete a message from the current room. The one argument that should be
679 passed to this command is the message number of the message to be deleted.
680 The return value will be OK if the message was deleted, or an ERROR code.
683 MOVE (MOVE a message to a different room)
685 Move a message to a different room. The two arguments that should be passed
686 to this command are the message number of the message to be deleted, and the
687 name of the target room. If the operation succeeds, the message will be
688 deleted from the current room and moved to the target room. An ERROR code
689 usually means that either the user does not have permission to perform this
690 operation, or that the target room does not exist.
693 KILL (KILL current room)
695 This command deletes the current room. It accepts a single argument, which
696 should be nonzero to actually delete the room, or zero to merely check
697 whether the room can be deleted.
699 Once the room is deleted, the current room is undefined. It is suggested
700 that client software immediately GOTO another room (usually _BASEROOM_)
701 after this command completes.
703 Possible return codes:
705 OK - room has been deleted (or, if checking only, request is valid).
706 ERROR+NOT_LOGGED_IN - no user is logged in.
707 ERROR+HIGHER_ACCESS_REQUIRED - not enough access to delete rooms.
708 ERROR+NOT_HERE - this room can not be deleted.
711 CRE8 (CRE[ate] a new room)
713 This command is used to create a new room. Like some of the other
714 commands, it provides a mechanism to first check to see if a room can be
715 created before actually executing the command. CRE8 accepts the following
718 0 - Create flag. Set this to 1 to actually create the room. If it is
719 set to 0, the server merely checks that there is a free slot in which to
720 create a new room, and that the user has enough access to create a room. It
721 returns OK if the client should go ahead and prompt the user for more info,
722 or ERROR or ERROR+HIGHER_ACCESS_REQUIRED if the command will not succeed.
723 1 - Name for new room.
724 2 - Access type for new room:
726 1 - Private; can be entered by guessing the room's name
727 2 - Private; can be entered by knowing the name *and* password
728 3 - Private; invitation only (sometimes called "exclusive")
729 3 - Password for new room (if it is a type 2 room)
730 4 - Floor number on which the room should reside (optional)
732 If the create flag is set to 1, the room is created (unless something
733 went wrong and an ERROR return is sent), and the server returns OK, but
734 the session is **not** automatically sent to that room. The client still
735 must perform a GOTO command to go to the new room.
738 FORG (FORGet the current room)
740 This command is used to forget (zap) the current room. For those not
741 familiar with Citadel, this terminology refers to removing the room from
742 a user's own known rooms list, *not* removing the room itself. After a
743 room is forgotten, it no longer shows up in the user's known room list,
744 but it will exist in the user's forgotten room list, and will return to the
745 known room list if the user goes to the room (in Citadel, this is
746 accomplished by explicitly typing the room's name in a <.G>oto command).
748 The command takes no arguments. If the command cannot execute for any
749 reason, ERROR will be returned. ERROR+NOT_LOGGED_IN or ERROR+NOT_HERE may
750 be returned as they apply.
752 If the command succeeds, OK will be returned. At this point, the current
753 room is **undefined**, and the client software is responsible for taking
754 the user to another room before executing any other room commands (usually
755 this will be _BASEROOM_ since it is always there).
758 MESG (read system MESsaGe)
760 This command is used to display system messages and/or help files. The
761 single argument it accepts is the name of the file to display. IT IS CASE
762 SENSITIVE. Citadel/UX looks for these files first in the "messages"
763 subdirectory and then in the "help" subdirectory.
765 If the file is found, LISTING_FOLLOWS is returned, followed by a pathname
766 to the file being displayed. Then the message is printed, in format type 0
767 (see MSG0 command for more information on this). If the file is not found,
770 There are some "well known" names of system messages which client software
771 may expect most servers to carry:
773 hello - Welcome message, to be displayed before the user logs in.
774 changepw - To be displayed whenever the user is prompted for a new
775 password. Warns about picking guessable passwords and such.
776 register - Should be displayed prior to the user entering registration.
777 Warnings about not getting access if not registered, etc.
778 help - Main system help file.
779 goodbye - System logoff banner; display when user logs off.
780 roomaccess - Information about how public rooms and different types of
781 private rooms function with regards to access.
782 unlisted - Tells users not to choose to be unlisted unless they're
783 really paranoid, and warns that aides can still see
784 unlisted userlog entries.
786 Citadel/UX provides these for the Citadel/UX Unix text client. They are
787 probably not very useful for other clients:
789 mainmenu - Main menu (when in idiot mode).
794 saveopt - Options to save a message, abort, etc.
795 entermsg - Displayed just before a message is entered, when in
799 GNUR (Get Next Unvalidated User)
801 This command shows the name of a user that needs to be validated. If there
802 are no unvalidated users, OK is returned. Otherwise, MORE_DATA is returned
803 along with the name of the first unvalidated user the server finds. All of
804 the usual ERROR codes may be returned as well (for example, if the user is
805 not an Aide and cannot validate users).
807 A typical "Validate New Users" command would keep executing this command,
808 and then validating each user it returns, until it returns OK when all new
809 users have been validated.
812 GREG (Get REGistration for user)
814 This command retrieves the registration info for a user, whose name is the
815 command's sole argument. All the usual error messages can be returned. If
816 the command succeeds, LISTING_FOLLOWS is returned, followed by the user's name
817 (retrieved from the userlog, with the right upper and lower case etc.) The
818 contents of the listing contains one field per line, followed by the usual
819 000 on the last line.
821 The following lines are defined. Others WILL be added in the futre, so all
822 software should be written to read the lines it knows about and then ignore
828 Line 4: Street address or PO Box
829 Line 5: City/town/village/etc.
830 Line 6: State/province/etc.
832 Line 8: Telephone number
834 Line 10: Internet e-mail address
836 Users without Aide privileges may retrieve their own registration using
837 this command. This can be accomplished either by passing the user's own
838 name as the argument, or the string "_SELF_". The command will always
839 succeed when used in this manner, unless no user is logged in.
844 This command is used to validate users. Obviously, it can only be executed
845 by users with Aide level access. It should be passed two parameters: the
846 name of the user to validate, and the desired access level
848 If the command succeeds, OK is returned. The user's access level is changed
849 and the "need validation" bit is cleared. If the command fails for any
850 reason, ERROR, ERROR+NO_SUCH_USER, or ERROR+HIGHER_ACCESS_REQUIRED will be
854 EINF (Enter INFo file for room)
856 Transmit the info file for the current room with this command. EINF uses
857 a boolean flag (1 or 0 as the first and only argument to the command) to
858 determine whether the client actually wishes to transmit a new info file, or
859 is merely checking to see if it has permission to do so.
861 If the command cannot succeed, it returns ERROR.
862 If the client is only checking for permission, and permission will be
863 granted, OK is returned.
864 If the client wishes to transmit the new info file, SEND_LISTING is
865 returned, and the client should transmit the text of the info file, ended
866 by the usual 000 on a line by itself.
871 This is a simple user listing. It always succeeds, returning
872 LISTING_FOLLOWS followed by zero or more user records, 000 terminated. The
873 fields on each line are as follows:
878 4. Date/time of last login (Unix format)
881 7. Password (listed only if the user requesting the list is an Aide)
883 Unlisted entries will also be listed to Aides logged into the server, but
884 not to ordinary users.
887 REGI (send REGIstration)
889 Clients will use this command to transmit a user's registration info. If
890 no user is logged in, ERROR+NOT_LOGGED_IN is returned. Otherwise,
891 SEND_LISTING is returned, and the server will expect the following information
892 (terminated by 000 on a line by itself):
895 Line 2: Street address or PO Box
896 Line 3: City/town/village/etc.
897 Line 4: State/province/etc.
899 Line 6: Telephone number
900 Line 7: e-mail address
903 CHEK (CHEcK various things)
905 When logging in, there are various things that need to be checked. This
906 command will return ERROR+NOT_LOGGED_IN if no user is logged in. Otherwise
907 it returns OK and the following parameters:
909 0: Number of new private messages in Mail>
910 1: Nonzero if the user needs to register
911 2: (Relevant to Aides only) Nonzero if new users require validation
916 This command deletes a file from the room's directory, if there is one. The
917 name of the file to delete is the only parameter to be supplied. Wildcards
918 are not acceptable, and any slashes in the filename will be converted to
919 underscores, to prevent unauthorized access to neighboring directories. The
920 possible return codes are:
922 OK - Command succeeded. The file was deleted.
923 ERROR+NOT_LOGGED_IN - Not logged in.
924 ERROR+HIGHER_ACCESS_REQUIRED - Not an Aide or Room Aide.
925 ERROR+NOT_HERE - There is no directory in this room.
926 ERROR+FILE_NOT_FOUND - Requested file was not found.
931 This command is similar to DELF, except that it moves a file (and its
932 associated file description) to another room. It should be passed two
933 parameters: the name of the file to move, and the name of the room to move
934 the file to. All of the same return codes as DELF may be returned, and also
935 one additional one: ERROR+NO_SUCH_ROOM, which means that the target room
936 does not exist. ERROR+NOT_HERE could also mean that the target room does
937 not have a directory.
940 NETF (NETwork send a File)
942 This command is similar to MOVF, except that it attempts to send a file over
943 the network to another system. It should be passed two parameters: the name
944 of the file to send, and the node name of the system to send it to. All of
945 the same return codes as MOVF may be returned, except for ERROR+NO_SUCH_ROOM.
946 Instead, ERROR+NO_SUCH_SYSTEM may be returned if the name of the target
949 The name of the originating room will be sent along with the file. Most
950 implementations will look for a room with the same name at the receiving end
951 and attempt to place the file there, otherwise it goes into a bit bucket room
952 for miscellaneous files. This is, however, beyond the scope of this document;
953 see elsewhere for more details.
956 RWHO (Read WHO's online)
958 Displays a list of all users connected to the server. No error codes are
959 ever returned. LISTING_FOLLOWS will be returned, followed by zero or more
960 lines containing the following three fields:
962 0 - Session ID. Citadel/UX fills this with the pid of a server program.
964 2 - The name of the room the user is currently in. This field might not
965 be displayed (for example, if the user is in a private room) or it might
966 contain other information (such as the name of a file the user is
968 3 - (server v4.03 and above) The name of the host the client is connecting
969 from, or "localhost" if the client is local.
970 4 - (server v4.04 and above) Description of the client software being used
971 5 - The last time, locally to the server, that a command was received from
972 this client (Note: NOOP's don't count)
973 6 - The last command received from a client. (NOOP's don't count)
974 7 - Session flags. These are: + (spoofed address), - (STEALTH mode), *
975 (posting) and . (idle). (Citserver 5.02 and above)
977 The listing is terminated, as always, with the string "000" on a line by
981 OPEN (OPEN a file for download)
983 This command is used to open a file for downloading. Only one download
984 file may be open at a time. The only argument to this command is the name
985 of the file to be opened. The user should already be in the room where the
986 file resides. Possible return codes are:
989 ERROR+NOT_HERE (no directory in this room)
990 ERROR+FILE_NOT_FOUND (could not open the file)
994 If the file is successfully opened, OK will be returned, along with the
995 size (in bytes) of the file, and (in version 5.00 and above) the time of last
999 CLOS (CLOSe the download file)
1001 This command is used to close the download file. It returns OK if the
1002 file was successfully closed, or ERROR if there wasn't any file open in the
1006 READ (READ from the download file)
1008 Two arguments are passed to this command. The first is the starting position
1009 in the download file, and the second is the total number of bytes to be
1010 read. If the operation can be performed, BINARY_FOLLOWS will be returned,
1011 along with the number of bytes to follow. Then, immediately following the
1012 newline, will be that many bytes of binary data. The client *must* read
1013 exactly that number of bytes, otherwise the client and server will get out
1016 If the operation cannot be performed, any of the usual error codes will be
1020 UOPN (OPeN a file for Uploading)
1022 This command is similar to OPEN, except that this one is used when the
1023 client wishes to upload a file to the server. The first argument is the name
1024 of the file to create, and the second argument is a one-line comment
1025 describing the contents of the file. Only one upload file may be open at a
1026 time. Possible return codes are:
1029 ERROR+NOT_HERE (no directory in this room)
1030 ERROR+FILE_NOT_FOUND (a name must be specified)
1031 ERROR (miscellaneous errors)
1032 ERROR+ALREADY_EXISTS (a file with the same name already exists)
1035 If OK is returned, the command has succeeded and writes may be performed.
1038 UCLS (CLoSe the Upload file)
1040 Close the file opened with UOPN. An argument of "1" should be passed to
1041 this command to close and save the file; otherwise, the transfer will be
1042 considered aborted and the file will be deleted. This command returns OK
1043 if the operation succeeded or ERROR if it did not.
1046 WRIT (WRITe to the upload file)
1048 If an upload file is open, this command may be used to write to it. The
1049 argument passed to this command is the number of bytes the client wishes to
1050 transmit. An ERROR code will be returned if the operation cannot be
1053 If the operation can be performed, SEND_BINARY will be returned, followed
1054 by the number of bytes the server is expecting. The client must then transmit
1055 exactly that number of bytes. Note that in the current implementation, the
1056 number of bytes the server is expecting will always be the number of bytes
1057 the client requested to transmit, but the client software should never assume
1058 that this will always happen, in case changes are made later.
1061 QUSR (Query for a USeR)
1063 This command is used to check to see if a particular user exists. The only
1064 argument to this command is the name of the user being searched for. If
1065 the user exists, OK is returned, along with the name of the user in the userlog
1066 (so the client software can learn the correct upper/lower casing of the name
1067 if necessary). If the user does not exist, ERROR+NO_SUCH_USER is returned.
1068 No login or current room is required to utilize this command.
1071 OIMG (Open an IMaGe file)
1073 Open an image (graphics) file for downloading. Once opened, the file can be
1074 read as if it were a download file. This implies that an image and a download
1075 cannot be opened at the same time. OIMG returns the same result codes as OPEN.
1077 All images will be in GIF (Graphics Interchange Format). In the case of
1078 Citadel/UX, the server will convert the supplied filename to all lower case,
1079 append the characters ".gif" to the filename, and look for it in the "images"
1080 subdirectory. As with the MESG command, there are several "well known"
1081 images which are likely to exist on most servers:
1083 hello - "Welcome" graphics to be displayed alongside MESG "hello"
1084 goodbye - Logoff banner graphics to be displayed alongside MESG "goodbye"
1085 background - Background image (usually tiled) for graphical clients
1087 The following "special" image names are defined in Citadel/UX server version
1090 _userpic_ - Picture of a user (send the username as the second argument)
1091 _floorpic_ - A graphical floor label (send the floor number as the second
1092 argument). Clients which request a floor picture will display
1093 the picture *instead* of the floor name.
1094 _roompic_ - A graphic associated with the *current* room. Clients which
1095 request a room picture will display the picture in *addition*
1096 to the room name (i.e. it's used for a room banner, as
1097 opposed to the floor picture's use in a floor listing).
1100 NETP (authenticate as network session with system NET Password)
1102 This command is used by client software to identify itself as a transport
1103 session for IGnet/Open BBS to BBS networking. It should be called with
1104 two arguments: the node name of the calling system, and the system net
1105 password for the server. If the authentication succeeds, NETP will return
1106 OK, otherwise, it returns ERROR.
1109 NUOP (Network Upload OPen file)
1111 Open a network spool file for uploading. The client must have already
1112 identified itself as a network session using the NETP command. If the command
1113 returns OK, the client may begin transmitting IGnet/Open spool data using
1114 a series of WRIT commands. When a UCLS command is issued, the spooled data
1115 is entered into the BBS if the argument to UCLS is 1 or discarded if the
1116 argument to UCLS is 0. If the client has not authenticated itself with a
1117 NETP command, ERROR+HIGHER_ACCESS_REQUIRED will be returned.
1120 NDOP (Network Download OPen file)
1122 Open a network spool file for downloading. The client must have already
1123 identified itself as a network session using the NETP command. If the command
1124 returns OK, the client may begin receiving IGnet/Open spool data using
1125 a series of READ commands. When a CLOS command is issued, the spooled data
1126 is deleted from the server and may not be read again. If the client has not
1127 authenticated itself with a NETP command, ERROR+HIGHER_ACCESS_REQUIRED will
1131 LFLR (List all known FLooRs)
1133 On systems supporting floors, this command lists all known floors. The
1134 command accepts no parameters. It will return ERROR+NOT_LOGGED_IN if no
1135 user is logged in. Otherwise it returns LISTING_FOLLOWS and a list of
1136 the available floors, each line consisting of three fields:
1138 1. The floor number associated with the floor
1139 2. The name of the floor
1140 3. Reference count (number of rooms on this floor)
1143 CFLR (Create a new FLooR)
1145 This command is used to create a new floor. It should be passed two
1146 arguments: the name of the new floor to be created, and a 1 or 0 depending
1147 on whether the client is actually creating a floor or merely checking to
1148 see if it has permission to create the floor. The user must be logged in
1149 and have Aide privileges to create a floor.
1151 If the command succeeds, it will return OK followed by the floor number
1152 associated with the new floor. Otherwise, it will return ERROR (plus perhaps
1153 HIGHER_ACCESS_REQUIRED, ALREADY_EXISTS, or INVALID_FLOOR_OPERATION)
1154 followed by a description of why the command failed.
1159 This command is used to delete a floor. It should be passed two
1160 argument: the *number* of the floor to be deleted, and a 1 or 0 depending
1161 on whether the client is actually deleting the floor or merely checking to
1162 see if it has permission to delete the floor. The user must be logged in
1163 and have Aide privileges to delete a floor.
1165 Floors that contain rooms may not be deleted. If there are rooms on a floor,
1166 they must be either deleted or moved to different floors first. This implies
1167 that the Main Floor (floor 0) can never be deleted, since Lobby>, Mail>, and
1168 Aide> all reside on the Main Floor and cannot be deleted.
1170 If the command succeeds, it will return OK. Otherwise it will return
1171 ERROR (plus perhaps HIGHER_ACCESS_REQUIRED or INVALID_FLOOR_OPERATION)
1172 followed by a description of why the command failed.
1177 Edit the parameters of a floor. The client may pass one or more parameters
1180 1. The number of the floor to be edited
1181 2. The desired new name
1183 More parameters may be added in the future. Any parameters not passed to
1184 the server will remain unchanged. A minimal command would be EFLR and a
1185 floor number -- which would do nothing. EFLR plus the floor number plus a
1186 floor name would change the floor's name.
1188 If the command succeeds, it will return OK. Otherwise it will return
1189 ERROR (plus perhaps HIGHER_ACCESS_REQUIRED or INVALID_FLOOR_OPERATION)
1192 IDEN (IDENtify the client software)
1194 The client software has the option to identify itself to the server.
1195 Currently, the server does nothing with this information except to write
1196 it to the syslog to satisfy the system administrator's curiosity. Other
1197 uses might become apparent in the future.
1199 The IDEN command should contain five fields: a developer ID number (same as
1200 the server developer ID numbers in the INFO command -- please obtain one if
1201 you are a new developer), a client ID number (which does not have to be
1202 globally unique - only unique within the domain of the developer number),
1203 a version number, a free-form text string describing the client, and the name
1204 of the host the user is located at.
1206 It is up to the server to determine whether to accept the host name or to
1207 use the host name it has detected itself. Generally, if the client is
1208 running on a trusted host (either localhost or a well-known publically
1209 accessible client) it should use the host name transmitted by IDEN,
1210 otherwise it should use the host name it has detected itself.
1212 IDEN always returns OK, but since that's the only way it ever returns
1213 there's no point in checking the result code.
1216 IPGM (identify as an Internal ProGraM)
1218 IPGM is a low-level command that should not be used by normal user clients.
1219 It is used for various utilities to communicate with the server on the same
1220 host. For example, the networker (netproc.c) logs onto the server as an
1221 internal program in order to fetch and store messages. Since user clients
1222 do not utilize this command (or any of its companion commands), developers
1223 writing Citadel-compatible servers need not implement it.
1225 The sole argument to IPGM is the system's internal program password. This
1226 password is generated by the setup program and stored in the config file.
1227 Since internal programs have access to the config file, they know the correct
1230 IPGM returns OK for a correct authentication or ERROR otherwise.
1233 CHAT (enter CHAT mode)
1235 This command functions differently from every other command in the system. It
1236 is used to implement multi-user chat. For this to function, a new transfer
1237 mode, called START_CHAT_MODE, is implemented. If a client does not support
1238 chat mode, it should never send a CHAT command!
1240 In chat mode, messages may arrive asynchronously from the server at any
1241 time. The client may send messages at any time. This allows the arrival of
1242 messages without the client having to poll for them. Arriving messages will
1243 be of the form "user|message", where the "user" portion is, of course, the
1244 name of the user sending the message, and "message" is the message text.
1246 Chat mode ends when the server says it ends. The server will signal the end
1247 of chat mode by transmitting "000" on a line by itself. When the client reads
1248 this line, it must immediately exit from chat mode without sending any
1249 further traffic to the server. The next transmission sent to the server
1250 will be a regular server command.
1252 The Citadel/UX server understands the following commands:
1253 /quit - Exit from chat mode (causes the server to do an 000 end)
1254 /who - List users currently in chat
1255 /whobbs - List users currently in chat and on the bbs
1256 /me - Do an irc-style action.
1257 /join - Join a new "room" in which all messages are only heard by
1258 people in that room.
1259 /msg - /msg <user> <msg> will send the msg to <user> only.
1260 /help - Print help information
1261 NOOP - Do nothing (silently)
1263 Any other non-empty string is treated as message text and will be broadcast
1264 to other users currently in chat.
1267 SEXP (Send EXPress messages)
1269 This is one of two commands which implement "express messages" (also known
1270 as "paging"). An express message is a near-real-time message sent from one
1271 logged in user to another. When an express message is sent, it will be
1272 displayed the next time the target user executes a PEXP command.
1274 The SEXP command accepts two arguments: the name of the user to send the
1275 message to, and the text of the message. If the message is successfully
1276 transmitted, OK is returned. If the target user is not logged in or if
1277 anything else goes wrong, ERROR is returned.
1279 In Citadel/UX 5.00 and above, the reserved name "broadcast" may be used
1280 instead of a user name, to broadcast an express message to all users
1281 currently connected to the server.
1283 Do be aware that if an express message is transmitted to a user who is logged
1284 in using a client that does not check for express messages, the message will
1288 PEXP (Print EXPress messages)
1290 This command, called without any arguments, simply dumps out the contents
1291 of any waiting express messages. It returns ERROR if there is a problem,
1292 otherwise it returns LISTING_FOLLOWS followed by all messages.
1294 So how does the client know there are express messages waiting? It could
1295 execute a random PEXP every now and then. Or, it can check the byte in
1296 server return code messages, between the return code and the parameters. In
1297 much the same way as FTP uses "-" to signify a continuation, Citadel uses
1298 an "*" in this position to signify the presence of waiting express messages.
1301 EBIO (Enter BIOgraphy)
1303 Transmit to the server a free-form text file containing a little bit of
1304 information about the user for other users to browse. This is typically
1305 referred to as a 'bio' online. EBIO returns SEND_LISTING if it succeeds,
1306 after which the client is expected to transmit the file, or any of the usual
1307 ERROR codes if it fails.
1310 RBIO (Read BIOgraphy)
1312 Receive from the server a named user's bio. This command should be passed
1313 a single argument - the name of the user whose bio is requested. RBIO returns
1314 LISTING_FOLLOWS plus the bio file if the user exists and has a bio on file,
1315 ERROR+NO_SUCH_USER if the named user does not exist, or ERROR+FILE_NOT_FOUND
1316 if the user exists but has no bio on file.
1319 STEL (enter STEaLth mode)
1321 When in "stealth mode," a user will not show up in the "Who is online"
1322 listing (the RWHO server command). Only Aides may use stealth mode. The
1323 STEL command accepts one argument: a 1 indicating that the user wishes to
1324 enter stealth mode, or a 0 indicating that the user wishes to exit stealth
1325 mode. STEL returns OK if the command succeeded, ERROR+NOT_LOGGED_IN if no
1326 user is logged in, or ERROR+HIGHER_ACCESS_REQUIRED if the user is not an Aide.
1328 The STEL command also makes it so a user does not show up in the chat room
1332 LBIO (List users who have BIOs on file)
1334 This command is self-explanatory. Any user who has used EBIO to place a bio
1335 on file is listed. LBIO almost always returns LISTING_FOLLOWS followed by
1336 this listing, unless it experiences an internal error in which case ERROR
1340 MSG2 (read MeSsaGe, mode 2)
1342 MSG2 follows the same calling convention as MSG0. The difference between
1343 the two commands is that MSG2 outputs messages in standard RFC822 format
1344 rather than in Citadel/UX proprietary format.
1346 This command was implemented in order to make various gateway programs
1347 easier to implement, and to provide some sort of multimedia support in the
1348 future. Keep in mind that when this command is used, all messages will be
1349 output in fixed 80-column format.
1352 MSG3 (read MeSsaGe, mode 3 -- internal command)
1354 MSG3 is for use by internal programs only and should not be utilized by
1355 user-mode clients. It does require IPGM authentication. MSG3 follows the
1356 same calling convention as the other MSG commands, but upon success returns
1357 BINARY_FOLLOWS followed by a data block containing the _raw_ message format
1361 ENT3 (ENTer message, mode 3 -- internal command)
1363 ENT3 is for use by internal programs only and should not be utilized by
1364 user-mode clients. It does require IPGM authentication. This command posts
1365 a raw message straight into the message base without modification or performing
1366 any checks. It accepts the following arguments:
1368 0 - Post flag. This should be set to 1 to post a message. If it is
1369 set to 0, the server only returns OK or ERROR (plus any flags describing
1370 the error) without reading in a message. This is used to verify the operation
1371 before actually transmitting a message.
1372 1 - Recipient. This argument is utilized only for private mail messages.
1373 It is ignored for public messages. It contains, of course, the name of the
1374 recipient of the message.
1375 2 - The size (in bytes) of the message to be transmitted.
1377 ENT3 returns OK to tell the client that a message can be posted, ERROR if
1378 there would be a problem with the operation, or SEND_BINARY followed by a byte
1379 count if it is expecting the message to be transmitted.
1382 TERM (TERMinate another session)
1384 In a multithreaded environment, it sometimes becomes necessary to terminate
1385 a session that is unusable for whatever reason. The TERM command performs
1386 this task. Naturally, only Aides can execute TERM. The command should be
1387 called with a single argument: the session ID (obtained from an RWHO command)
1388 of the session to be terminated.
1390 TERM returns OK if the session was terminated, or ERROR otherwise. Note that
1391 a client program is prohibited from terminating the session it is currently
1395 NSET (Network SETup commands)
1397 Aides may use this command to configure the networker. This command's
1398 parameters are passed directly to the 'netsetup' command line utility. If
1399 netsetup returns a non-zero exit code, ERROR is returned, along with the
1400 error message (if any). If netsetup returns a zero (success) exit code,
1401 LISTING_FOLLOWS is returned, followed by zero or more lines of output (since
1402 netsetup may have information to display, such as a room or node list) and
1403 the usual '000' listing terminator.
1406 DOWN (shut DOWN the server)
1408 This command, which may only be executed by an Aide, immediately shuts down
1409 the server. It is only implemented on servers on which such an operation is
1410 possible, such as a multithreaded Citadel engine. The server does not restart.
1411 DOWN returns OK if the user is allowed to shut down the server, in which case
1412 the client program should expect the connection to be immediately broken.
1415 SCDN (Schedule or Cancel a shutDowN)
1417 SCDN sets or clears the "scheduled shutdown" flag. Pass this command a 1 or
1418 0 to respectively set or clear the flag. When the "scheduled shutdown" flag is
1419 set, the server will be shut down when there are no longer any users logged in.
1420 Any value other than 0 or 1 will not change the flag, only report its state.
1421 No users will be kicked off the system, and in fact the server is still available
1422 for new connections. The command returns ERROR if it fails; otherwise, it
1423 returns OK followed by a number representing the current state of the flag.
1426 EMSG (Enter a system MeSsaGe)
1428 This is the opposite of the MESG command - it allows the creation and editing
1429 of system messages. The only argument passed to EMSG is the name of the
1430 file being transmitted. If the file exists in any system message directory
1431 on the server it will be overwritten, otherwise a new file is created. EMSG
1432 returns SEND_LISTING on success or ERROR+HIGHER_ACCESS_REQUIRED if the user
1435 Typical client software would use MESG to retrieve any existing message into
1436 an edit buffer, then present an editor to the user and run EMSG if the changes
1440 UIMG (Upload an IMaGe file)
1442 UIMG is complemenary to OIMG; it is used to upload an image to the server.
1443 The first parameter supplied to UIMG should be 0 if the client is only checking
1444 for permission to upload, or 1 if the client is actually attempting to begin
1445 the upload operation. The second argument is the name of the file to be
1446 transmitted. In Citadel/UX, the filename is converted to all lower case,
1447 appended with the characters ".gif", and stored in the "images" directory.
1449 UIMG returns OK if the client has permission to perform the requested upload,
1450 or ERROR+HIGHER_ACCESS_REQUIRED otherwise. If the client requested to begin
1451 the operation (first parameter set to 1), an upload file is opened, and the
1452 client should begin writing to it with WRIT commands, then close it with a
1455 The supplied filename should be one of:
1457 -> _userpic_ (Server will attempt to write to the user's online photo)
1458 -> Any of the "well known" filenames described in the writeup for the
1461 ----------------------------------------------
1462 The following are for citserver 5.02 and above
1463 ----------------------------------------------
1465 HCHG (Hostname CHanGe)
1467 HCHG is a command, usable by any user, that allows a user to change their RWHO
1468 host value. This will mask a client's originating hostname from normal
1469 users; access level 6 and higher see an entry right underneath the spoofed
1470 entry listing the actual hostname the user originates from.
1472 The format of an HCHG command is:
1476 If a HCHG command is successful, the value OK (200) is returned.
1479 RCHG (Roomname CHanGe)
1481 RCHG is a command, usable by any user, that allows a user to change their RWHO
1482 room value. This will mask a client's roomname from normal users; access
1483 level 6 and higher see an entry right underneath the spoofed entry listing
1484 the actual room the user is in.
1486 The format of an RCHG command is:
1490 If a RCHG command is successful, the value OK (200) is returned.
1493 UCHG (Username CHanGe)
1495 UCHG is an aide-level command which allows an aide to effectively change their
1496 username. If this value is blank, the user goes into stealth mode (see
1498 will show up as being from the real username in this mode, however. In
1499 addition, the RWHO listing will include both the spoofed and real usernames.
1501 The format of an UCHG command is:
1505 If a UCHG command is successful, the value OK (200) is returned.
1508 TIME (get server local TIME)
1510 TIME returns OK followed by the current time measured in seconds since
1511 00:00:00 GMT, Jan 1, 1970 (standard Unix format).
1513 This is used in allowing a client to calculate idle times.
1516 AGUP (Administrative Get User Parameters)
1517 ASUP (Administrative Set User Parameters)
1519 These commands are only executable by Aides and by server extensions running
1520 at system-level. They are used to get/set any and all parameters relating to
1521 a user account. AGUP requires only one argument: the name of the user in
1522 question. SGUP requires all of the parameters to be set. The parameters are
1523 as follows, and are common to both commands:
1527 2 - Flags (see citadel.h)
1532 7 - Timestamp of last call
1533 8 - Purge time (in days) for this user (or 0 to use system default)
1535 Upon success, AGUP returns OK followed by all these parameters, and ASUP
1536 simply returns OK. If the client has insufficient access to perform the
1537 requested operation, ERROR+HIGHER_ACCESS_REQUIRED is returned. If the
1538 requested user does not exist, ERROR+NO_SUCH_USER is returned.
1542 GPEX (Get Policy for message EXpiration)
1544 Returns the policy of the current room, floor, or site regarding the automatic
1545 purging (expiration) of messages. The following policies are available:
1546 0 - Fall back to the policy of the next higher level. If this is a room,
1547 use the floor's default policy. If this is a floor, use the system
1548 default policy. This is an invalid value for the system policy.
1549 1 - Do not purge messages automatically.
1550 2 - Purge by message count. (Requires a value: number of messages)
1551 3 - Purge by message age. (Requires a value: number of days)
1553 The format of this command is: GPEX <which>
1554 The value of <which> must be one of: "room" "floor" "site"
1556 If successful, GPEX returns OK followed by <policy>|<value>.
1560 SPEX (Set Polict for message EXpiration)
1562 Sets the policy of the current room, floor, or site regarding the automatic
1563 purging (expiration) of messages. See the writeup for the GPEX command for
1564 the list of available policies.
1566 The format of this command is: SPEX <which>|<policy>|<value>
1567 The value of <which> must be one of: "room" "floor" "site"
1569 If successful, GPEX returns OK; otherwise, an ERROR code is returned.
1573 CONF (get or set global CONFiguration options)
1575 Retrieves or sets various system-wide configuration and policy options. This
1576 command is only available to Aides. The sole parameter accepted is a command,
1577 which should be either GET or SET. If the GET command succeeds, CONF will
1578 return LISTING_FOLLOWS followed by the fields described below, one line at a
1579 time. If the SET command succeeds, CONF will return SEND_LISTING and expect
1580 the fields described below, one line at a time (don't worry about other fields
1581 being added in the future; if a 'short' configuration list is sent, the missing
1582 values at the end will be left unchanged on the system). If either command
1583 fails for any reason, ERROR is returned.
1585 The configuration lines are as follows:
1588 2. Fully qualified domain name
1589 3. Human-readable node name
1590 4. Landline telephone number of this system
1591 5. Flag (0 or 1) - creator of private room automatically becomes room aide
1592 6. Server connection idle timeout (in seconds)
1593 7. Initial access level for new users
1594 8. Flag (0 or 1) - require registration for new users
1595 9. Flag (0 or 1) - automatically move Problem User messages to twit room
1596 10. Name of twit room
1597 11. Text of <more> prompt
1598 12. Flag (0 or 1) - restrict access to Internet mail
1599 13. Geographic location of this system
1600 14. Name of the system administrator
1601 15. Number of maximum concurrent sessions allowed on the server
1602 16. Password for server-to-server networking
1603 17. Default purge time (in days) for users
1604 18. Default purge time (in days) for rooms
1608 EXPI (EXPIre system objects)
1610 Begins purge operations for objects which, according to site policy, are
1611 "old" and should be removed. EXPI should be called with one argument, one of:
1613 "messages" (purge old messages out of each room)
1614 "users" (purge old users from the userlog)
1616 EXPI returns OK (probably after a long delay while it does its work) if it
1617 succeeds; otherwise it returns an ERROR code.
1619 This command is probably temporary, until we can work some sort of scheduler
1620 into the system. It is implemented in the serv_expire module.