1 SESSION LAYER PROTOCOL FOR CITADEL/UX
2 (c) 1995-1998 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 a few of the currently used methods.
34 Keep in mind that the server program itself does not speak any protocols
35 lower than the session layer. Instead, it reads all input from stdin, and
36 writes all output to stdout. This implies that it is the responsibility of
37 other programs to provide a usable transport to the client programs.
39 One way to connect to a server is to use a set of pipes. This does of
40 course assume that the client and server are running on the same computer.
41 When the client starts up, the first thing that it does is create two pipes,
42 which it temporarily dup()'s to stdin and stdout. Then it proceeds to
43 fork() and exec() to a copy of the server program, which inherits the
44 pipes as its standard input and output - exactly the desired effect. The
45 client program can then re-connect its own stdin and stdout to where they're
46 supposed to be, and use the pipes to send and receive server messages.
48 Another way is to use TCP/IP. Under Unix-like systems this is easily
49 accomplished using the "inetd" superserver program, which can take programs
50 like the Citadel/UX server and offer connections to clients over a TCP or
51 UDP port. See the install documentation (or the inetd documentation from
52 your OS) for information on how to do this. Always use TCP ports for
53 Citadel/UX sessions. Since our session layer assumes a clean, reliable,
54 sequenced connection, the use of UDP would render the server unstable and
55 unusable. When operating in a TCP/IP environment, the port number officially
56 assigned to Citadel is 504.
59 GENERAL INFORMATION ABOUT THE SERVER
60 ------------------------------------
62 The server is connection-oriented and stateful: each client requires its own
63 connection to a server process, and when a command is sent, the client must
64 read the response, and then transfer data or change modes if necessary.
66 The session layer is very much like other Internet protocols such as SMTP
67 or NNTP. A client program sends one-line commands to the server, and the
68 server responds with a three-digit numeric result code followed by a message
69 describing what happened. This cycle continues until the end of the
72 Unlike protocols such as FTP, all data transfers occur in-band. This means
73 that the same connection that is used for exchange of client/server
74 messages, will also be used to transfer data back and forth. (FTP opens a
75 separate connection for data transfers.) We do this to allow the server to
76 function over transports which can only handle one session at a time (such
77 as a dialup connection).
83 The server will respond to all commands with a 3-digit result code, which
84 will be the first three characters on the line. The rest of the line may
85 contain a human-readable string explaining what happened. (Some client
86 software will display some of these strings to the user.)
88 The first digit is the most important. The following codes are defined for
89 this position: ERROR, OK, MORE_DATA, LISTING_FOLLOWS, and SEND_LISTING.
91 The second and third digits may provide a reason as to why a command
92 succeeded or failed. See ipcdef.h for the available codes.
94 ERROR means the command did not complete.
95 OK means the command executed successfully.
96 MORE_DATA means the command executed partially. Usually this means that
97 another command needs to be executed to complete the operation. For example,
98 sending the USER command to log in a user usually results in a MORE_DATA
99 result code, because the client needs to execute a PASS command to send the
100 password and complete the login.
101 LISTING_FOLLOWS means that after the server response, the server will
102 output a listing of some sort. The client *must* read the listing, whether
103 it wants to or not. The end of the listing is signified by the string
104 "000" on a line by itself.
105 SEND_LISTING is the opposite of LISTING_FOLLOWS. It means that the client
106 should begin sending a listing of some sort. The client *must* send something,
107 even if it is an empty listing. Again, the listing ends with "000" on a line
114 Zero or more parameters may be passed to a command. When more than one
115 parameter is passed to a command, they should be separated by the "|"
118 In this example, we're using the "SETU" command and passing three
119 parameters: 80, 24, and 260.
121 When the server spits out data that has parameters, if more than one
122 parameter is returned, they will be separated by the "|" symbol like
125 In this example, we just executed the "GETU" command, and it returned us
126 an OK result code (the '2' in the 200) and three parameters: 80, 24, and
133 This is a listing of all the commands that a Citadel/UX server can execute.
138 This command does nothing. It takes no arguments and always returns
139 OK. It is intended primarily for testing and development, but it might also
140 be used as a "keep alive" command to prevent the server from timing out, if
141 it's running over a transport that needs this type of thing.
144 ECHO (ECHO something)
146 This command also does nothing. It simply returns OK followed by whatever
152 Terminate the server connection. This command takes no arguments. It
153 returns OK and closes the connection immediately.
158 Log out the user without closing the server connection. It always returns
159 OK even if no user is logged in.
162 USER (send USER name)
164 The first step in logging in a user. This command takes one argument: the
165 name of the user to be logged in. If the user exists, a MORE_DATA return
166 code will be sent, which means the client should execute PASS as the next
167 command. If the user does not exist, ERROR is returned.
172 The second step in logging in a user. This command takes one argument: the
173 password for the user we are attempting to log in. If the password doesn't
174 match the correct password for the user we specified for the USER command,
175 or if a USER command has not been executed yet, ERROR is returned. If the
176 password is correct, OK is returned and the user is now logged in... and
177 most of the other server commands can now be executed. Along with OK, the
178 following parameters are returned:
180 0 - The user's name (in case the client wants the right upper/lower casing)
181 1 - The user's current access level
184 4 - Various flags (see citadel.h)
188 NEWU (create NEW User account)
190 This command creates a new user account and logs it in. The argument to
191 this command will be the name of the account. No case conversion is done
192 on the name. Note that the new account is installed with a default
193 configuration, and no password, so the client should immediately prompt the
194 user for a password and install it with the SETP command as soon as this
195 command completes. This command returns OK if the account was created and
196 logged in, or ERROR if another user already exists with this name. If OK,
197 it will also return the same parameters that PASS returns.
200 AUTO (AUTOmatic login **OBSLETE** )
202 Citadel/UX no longer supports this type of authentication. It was formerly
203 used to automatically authenticate a user based on the user ID under which
204 the server was running. Due to the new multithreaded architecture of the
205 server, this is no longer possible.
208 SETP (SET new Password)
210 This command sets a new password for the currently logged in user. The
211 argument to this command will be the new password. The command always
212 returns OK, unless the client is not logged in, in which case it will return
216 LKRN (List Known Rooms with New messages)
218 List known rooms with new messages. If the client is not logged in, ERROR
219 is returned. Otherwise, LISTING_FOLLOWS is returned, followed by the room
220 listing. Each line in the listing contains the full name of a room, followed
221 by the '|' symbol, and then a number that may contain the following bits:
224 #define QR_PERMANENT 1 /* Room does not purge */
225 #define QR_PRIVATE 4 /* Set for any type of private room */
226 #define QR_PASSWORDED 8 /* Set if there's a password too */
227 #define QR_GUESSNAME 16 /* Set if it's a guessname room */
228 #define QR_DIRECTORY 32 /* Directory room */
229 #define QR_UPLOAD 64 /* Allowed to upload */
230 #define QR_DOWNLOAD 128 /* Allowed to download */
231 #define QR_VISDIR 256 /* Visible directory */
232 #define QR_ANONONLY 512 /* Anonymous-Only room */
233 #define QR_ANON2 1024 /* Anonymous-Option room */
234 #define QR_NETWORK 2048 /* Shared network room */
235 #define QR_PREFONLY 4096 /* Preferred status needed to enter */
236 #define QR_READONLY 8192 /* Aide status required to post */
239 Other bits may be defined in the future. The listing terminates, as with
240 all listings, with "000" on a line by itself.
242 Version 4.01 and above only:
244 Starting with version 4.01 and above, floors are supported. The first
245 argument to LKRN should be the number of the floor to list rooms from. Only
246 rooms from this floor will be listed. If no arguments are passed to LKRN, or
247 if the floor number requested is (-1), rooms on all floors will be listed.
249 The third field displayed on each line is the number of the floor the room
250 is on. The LFLR command should be used to associate floor numbers with
255 LKRO (List Known Rooms with Old [no new] messages)
257 This follows the same usage and format as LKRN.
260 LZRM (List Zapped RooMs)
262 This follows the same usage and format as LKRN and LKRO.
265 LKRA (List All Known Rooms)
267 Same format. Lists all known rooms, with or without new messages.
270 LRMS (List all accessible RooMS)
272 Again, same format. This command lists all accessible rooms, known and
273 forgotten, with and without new messages. It does not, however, list
274 inaccessible private rooms.
277 GETU (GET User configuration)
279 This command retrieves the screen dimensions and user options for the
280 currently logged in account. ERROR will be returned if no user is logged
281 in, of course. Otherwise, OK will be returned, followed by three parameters.
282 The first parameter is the user's screen width, the second parameter is the
283 user's screen height, and the third parameter is a bag of bits with the
286 #define US_LASTOLD 16 /* Print last old message with new */
287 #define US_EXPERT 32 /* Experienced user */
288 #define US_UNLISTED 64 /* Unlisted userlog entry */
289 #define US_NOPROMPT 128 /* Don't prompt after each message */
290 #define US_DISAPPEAR 512 /* Use "disappearing msg prompts" */
291 #define US_PAGINATOR 2048 /* Pause after each screen of text */
293 There are other bits, too, but they can't be changed by the user (see below).
296 SETU (SET User configuration)
298 This command does the opposite of SETU: it takes the screen dimensions and
299 user options (which were probably obtained with a GETU command, and perhaps
300 modified by the user) and writes them to the user account. This command
301 should be passed three parameters: the screen width, the screen height, and
302 the option bits (see above).
304 Note that there exist bits here which are not listed in this document. Some
305 are flags that can only be set by Aides or the system administrator. SETU
306 will ignore attempts to toggle these bits. There also may be more user
307 settable bits added at a later date. To maintain later downward compatibility,
308 the following procedure is suggested:
310 1. Execute GETU to read the current flags
311 2. Toggle the bits that we know we can toggle
312 3. Execute SETU to write the flags
314 If we are passed a bit whose meaning we don't know, it's best to leave it
315 alone, and pass it right back to the server. That way we can use an old
316 client on a server that uses an unknown bit without accidentally clearing
317 it every time we set the user's configuration.
322 This command is used to goto a new room. When the user first logs in (login
323 is completed after execution of the PASS command) this command is
324 automatically and silently executed to take the user to the first room in the
325 system (usually called the Lobby).
327 This command can be passed one or two parameters. The first parameter is,
328 of course, the name of the room. Although it is not case sensitive, the
329 full name of the room must be used. Wildcard matching or unique string
330 matching of room names should be the responsibility of the client.
332 Note that the reserved room name "_BASEROOM_" can be passed to the server
333 to cause the goto command to take the user to the first room in the system,
334 traditionally known as the Lobby>. As long as a user is logged in, a
335 GOTO command to _BASEROOM_ is guaranteed to succeed. This is useful to
336 allow client software to return to the base room when it doesn't know
339 Citadel/UX server v4.01 and above, also has two additional reserved room
340 names. "_MAIL_" translates to the system's designated room for e-mail
341 messages, and "_BITBUCKET_" goes to whatever room has been chosen for messages
344 The second (and optional) parameter is a password, if one is required for
345 access to the room. This allows for all types of rooms to be accessed via
346 this command: for public rooms, invitation-only rooms to which the user
347 has access, and preferred users only rooms to which the user has access, the
348 room will appear in a room listing. For guess-name rooms, this command
349 will work transparently, adding the room to the user's known room list when
350 it completes. For passworded rooms, access will be denied if the password
351 is not supplied or is incorrect, or the command will complete successfully
352 if the password is correct.
354 The possible result codes are:
356 OK - The command completed successfully. User is now in the room.
357 (See the list of returned parameters below)
359 ERROR - The command did not complete successfully. Check the second and
360 third positions of the result code to find out what happened:
362 NOT_LOGGED_IN - Of course you can't go there. You didn't log in.
363 PASSWORD_REQUIRED - Either a password was not supplied, or the supplied
364 password was incorrect.
365 NO_SUCH_ROOM - The requested room does not exist.
367 The typical procedure for entering a passworded room would be:
369 1. Execute a GOTO command without supplying any password.
370 2. ERROR+PASSWORD_REQUIRED will be returned. The client now knows that
371 the room is passworded, and prompts the user for a password.
372 3. Execute a GOTO command, supplying both the room name and the password.
373 4. If OK is returned, the command is complete. If, however,
374 ERROR+PASSWORD_REQUIRED is still returned, tell the user that the supplied
375 password was incorrect. The user remains in the room he/she was previously
378 When the command succeeds, these parameters are returned:
379 0. The name of the room
380 1. Number of unread messages in this room
381 2. Total number of messages in this room
382 3. Info flag: set to nonzero if the user needs to read this room's info
383 file (see RINF command below)
384 4. Various flags associated with this room. (See LKRN cmd above)
385 5. The highest message number present in this room
386 6. The highest message number the user has read in this room
387 7. Boolean flag: 1 if this is a Mail> room, 0 otherwise.
388 8. Aide flag: 1 if the user is either the Room Aide for this room, *or* is
389 a regular Aide (this makes access checks easy).
391 ...and in server 4.01 and above:
392 9. The number of new Mail messages the user has (useful for alerting the
393 user to the arrival of new mail during a session)
395 ...and in server 4.03 and above:
396 10. The floor number this room resides on
399 MSGS (get pointers to MeSsaGeS in this room)
401 This command obtains a listing of all the messages in the current room
402 which the client may request. This command may be passed a single parameter:
403 either "all", "old", or "new" to request all messages, only old messages, or
404 new messages. Or it may be passed two parameters: "last" plus a number, in which
405 case that many message pointers will be returned, or "first" plus a number, for
406 the corresponding effect. If no parameters are specified, "all" is assumed.
408 In Citadel/UX 5.00 and above, the client may also specify "gt" plus a number, to
409 list all messages in the current room with a message number greater than the one
412 This command can return two possible results. An ERROR code may be returned
413 if no user is currently logged in or if something else went wrong. Otherwise,
414 LISTING_FOLLOWS will be returned, and the listing will consist of zero or
415 more message numbers, one per line. The listing ends, as always, with the
416 string "000" alone on a line by itself. The listed message numbers can be used
417 to request messages from the system.
420 MSG0 (read MeSsaGe, mode 0)
422 This is a command used to read the text of a message. "Mode 0" implies that
423 other MSG commands (MSG1, MSG2, etc.) will probably be added later on to read
424 messages in more robust formats. This command should be passed two arguments.
425 The first is the message number of the message being requested. In server
426 version 4.04 and above, the second argument may be set to either 0 to read the
427 entire message, or 1 to read the headers only.
429 The server should, of course, make sure that the client actually has access
430 to the message being requested before honoring this request. Citadel/UX does
431 so by checking the message number against the contents of the current room. If
432 it's not there, the request is denied.
434 If the request is denied, an ERROR code will be returned. Otherwise, the
435 LISTING_FOLLOWS code will be returned, followed by the contents of the message.
436 The following fields may be sent:
438 type= Formatting type. Currently, there are two defined types. Type 0 is
439 "traditional" Citadel formatting. This means that newlines should be treated
440 as spaces UNLESS the first character on the next line is a space. In other
441 words, only indented lines should generate a newline on the user's screen when
442 the message is being displayed. This allows a message to be formatted to the
443 reader's screen width. It also allows the use of proportional fonts.
444 Type 1 is a simple fixed-format message. The message should be displayed to
445 the user's screen as is, preferably in a fixed-width font that will fit 80
448 msgn= The message ID of this message on the system it originated on.
449 path= An e-mailable path back to the user who wrote the message.
451 time= The date and time of the message, in Unix format (the number of
452 seconds since midnight on January 1, 1970, GMT).
454 from= The name of the author of the message.
455 rcpt= If the message is a private e-mail, this is the recipient.
456 room= The name of the room the message originated in.
457 node= The short node name of the system this message originated on.
458 hnod= The long node name of the system this message originated on.
460 text Note that there is no "=" after the word "text". This string
461 signifies that the message text begins on the next line.
464 WHOK (WHO Knows room)
466 This command is available only to Aides. ERROR+HIGHER_ACCESS_REQUIRED will
467 be returned if the user is not an Aide. Otherwise, it returns
468 LISTING_FOLLOWS and then lists, one user per line, every user who has
469 access to the current room.
472 INFO (get server INFO)
474 This command will *always* return LISTING_FOLLOWS and then print out a
475 listing of zero or more strings. Client software should be written to expect
476 anywhere from a null listing to an infinite number of lines, to allow later
477 backward compatibility. The current implementation defines the following
478 parts of the listing:
480 Line 1 - Your unique session ID on the server
481 Line 2 - The node name of the server BBS
482 Line 3 - Human-readable node name of the server BBS
483 Line 4 - The fully-qualified domain name (FQDN) of the server
484 Line 5 - The name of the server software, i.e. "Citadel/UX 4.00"
485 Line 6 - (The revision level of the server code) * 100
486 Line 7 - The geographical location of the BBS (for USA: city and state)
487 Line 8 - The name of the system administrator
488 Line 9 - A number identifying the server type (see below)
489 Line 10 - The text of the system's paginator prompt
491 (version 4.01 and above only)
492 Line 11 - Floor Flag. 1 if the system supports floors, 0 otherwise.
494 *** NOTE! *** The "server type" code is intended to promote global
495 compatibility in a scenario in which developers have added proprietary
496 features to their servers or clients. We are attempting to avoid a future
497 situation in which users need to keep different client software around for
498 each BBS they use. *Please*, if you are a developer and plan to add
499 proprietary features:
501 -> Your client programs should still be able to utilize servers other than
503 -> Clients other than your own should still be able to utilize your server,
504 even if your proprietary extensions aren't supported.
505 -> Please contact Art Cancro <ajc@uncnsrd.mt-kisco.ny.us> and obtain a unique
506 server type code, which can be assigned to your server program.
507 -> If you document what you did in detail, perhaps it can be added to a
508 future release of the Citadel/UX program, so everyone can enjoy it. Better
509 yet, just work with the Citadel development team on the main source tree.
511 If everyone follows this scheme, we can avoid a chaotic situation with lots
512 of confusion about which client program works with which server, etc. Client
513 software can simply check the server type (and perhaps the revision level)
514 to determine ahead of time what commands may be utilized.
516 Please refer to "developers.txt" for information on what codes belong to whom.
520 RDIR (Read room DIRectory)
522 Use this command to read the directory of a directory room. ERROR+NOT_HERE
523 will be returned if the room has no directory, or some other error; ERROR +
524 HIGHER_ACCESS_REQUIRED will be returned if the room's directory is not
525 visible and the user does not have Aide or Room Aide privileges; otherwise
526 LISTING_FOLLOWS will be returned, followed by the room's directory. Each
527 line of the directory listing will contain three fields: a filename, the
528 length of the file, and a description.
530 The server message contained on the same line with LISTING_FOLLOWS will
531 contain the name of the system and the name of the directory, such as:
532 uncnsrd.mt-kisco.ny.us|/usr/bbs/files/my_room_directory
535 SLRP (Set Last-message-Read Pointer)
537 This command is used to mark messages as having been read. Its sole parameter
538 is the number of the last message that has been read. This allows the pointer
539 to be set at any arbitrary point in the room. Optionally, the parameter
540 "highest" may be used instead of a message number, to set the pointer to the
541 number of the highest message in the room, effectively marking all messages
542 in the room as having been read (ala the Citadel <G>oto command).
544 The command will return OK if the pointer was set, or ERROR if something
545 went wrong. If OK is returned, it will be followed by a single argument
546 containing the message number the last-read-pointer was set to.
549 INVT (INViTe a user to a room)
551 This command may only be executed by Aides, or by the room aide for the
552 current room. It is used primarily to add users to invitation-only rooms,
553 but it may also be used in other types of private rooms as well. Its sole
554 parameter is the name of the user to invite.
556 The command will return OK if the operation succeeded, or ERROR if it did
557 not. ERROR+HIGHER_ACCESS_REQUIRED may also be returned if the operation
558 would have been possible if the user had higher access, and ERROR+NOT_HERE
559 may be returned if the room is not a private room.
562 KICK (KICK a user out of a room)
564 This is the opposite of INVT: it is used to kick a user out of a private
565 room. It can also be used to kick a user out of a public room, but the
566 effect will only be the same as if the user <Z>apped the room - a non-stupid
567 user can simply un-zap the room to get back in.
570 GETR (GET Room attributes)
572 This command is used for editing the various attributes associated with a
573 room. A typical "edit room" command would work like this:
574 1. Use the GETR command to get the current attributes
575 2. Change some of them around
576 3. Use SETR (see below) to save the changes
577 4. Possibly also change the room aide using the GETA and SETA commands
579 GETR takes no arguments. It will only return OK if the SETR command will
580 also return OK. This allows client software to tell the user that he/she
581 can't edit the room *before* going through the trouble of actually doing the
582 editing. Possible return codes are:
584 ERROR+NOT_LOGGED_IN - No user is logged in.
585 ERROR+HIGHER_ACCESS_REQUIRED - Not enough access. Typically, only aides
586 and the room aide associated with the current room, can access this command.
587 ERROR+NOT_HERE - Lobby>, Mail>, and Aide> cannot be edited.
588 OK - Command succeeded. Parameters are returned.
590 If OK is returned, the following parameters will be returned as well:
592 0. The name of the room
593 1. The room's password (if it's a passworded room)
594 2. The name of the room's directory (if it's a directory room)
595 3. Various flags (bits) associated with the room (see LKRN cmd above)
597 (And on server version 4.01 and above ... )
598 4. The floor number on which the room resides
601 SETR (SET Room attributes)
603 This command sets various attributes associated with the current room. It
604 should be passed the following arguments:
606 0. The name of the room
607 1. The room's password (if it's a passworded room)
608 2. The name of the room's directory (if it's a directory room)
609 3. Various flags (bits) associated with the room (see LKRN cmd above)
610 4. "Bump" flag (see below)
612 (And on server version 4.01 and above, the client may also send ... )
613 5. The floor number on which the room should reside
615 *Important: You should always use GETR to retrieve the current attributes of
616 the room, then change what you want to change, and then use SETR to write it
617 all back. This is particularly important with respect to the flags: if a
618 particular bit is set, and you don't know what it means, LEAVE IT ALONE and
619 only toggle the bits you want to toggle. This will allow for upward
622 If the room is a private room, you have the option of causing all users who
623 currently have access, to forget the room. If you want to do this, set the
624 "bump" flag to 1, otherwise set it to 0.
629 This command is used to get the name of the Room Aide for the current room.
630 It will return ERROR+NOT_LOGGED_IN if no user is logged in, ERROR if there
631 is no current room, or OK if the command succeeded. Along with OK there will
632 be returned one parameter: the name of the Room Aide.
637 The opposite of GETA, used to set the Room Aide for the current room. One
638 parameter should be passed, which is the name of the user who is to be the
639 new Room Aide. Under Citadel/UX, this command may only be executed by Aides
640 and by the *current* Room Aide for the room. Return codes possible are:
641 ERROR+NOT_LOGGED_IN (Not logged in.)
642 ERROR+HIGHER_ACCESS_REQUIRED (Higher access required.)
643 ERROR+NOT_HERE (No current room, or room cannot be edited.
644 Under Citadel/UX, the Lobby> Mail> and Aide> rooms are non-editable.)
645 OK (Command succeeded.)
648 ENT0 (ENTer message, mode 0)
650 This command is used to enter messages into the system. It accepts four
653 0 - Post flag. This should be set to 1 to post a message. If it is
654 set to 0, the server only returns OK or ERROR (plus any flags describing
655 the error) without reading in a message. Client software should, in fact,
656 perform this operation at the beginning of an "enter message" command
657 *before* starting up its editor, so the user does not end up typing a message
658 in vain that will not be permitted to be saved. If it is set to 2, the
659 server will accept an "apparent" post name if the user is privileged enough.
660 This post name is arg 4.
661 1 - Recipient. This argument is utilized only for private mail messages.
662 It is ignored for public messages. It contains, of course, the name of the
663 recipient of the message.
664 2 - Anonymous flag. This argument is ignored unless the room allows
665 anonymous messages. In such rooms, this flag may be set to 1 to flag a
666 message as anonymous, otherwise 0 for a normal message.
667 3 - Format type. Any valid Citadel/UX format type may be used (this will
668 typically be 0; see the MSG0 command above).
669 4 - Post name. When postflag is 2, this is the name you are posting as.
670 This is an Aide only command.
672 Possible result codes:
673 OK - The request is valid. (Client did not set the "post" flag, so the
674 server will not read in message text.) If the message is an e-mail with
675 a recipient, the text that follows the OK code will contain the exact name
676 to which mail is being sent. The client can display this to the user. The
677 implication here is that the name that the server returns will contain the
678 correct upper and lower case characters. In addition, if the recipient is
679 having his/her mail forwarded, the forwarding address will be returned.
680 SEND_LISTING - The request is valid. The client should now transmit
681 the text of the message (ending with a 000 on a line by itself, as usual).
682 ERROR - Miscellaneous error. (Explanation probably follows.)
683 ERROR + NOT_LOGGED_IN - Not logged in.
684 ERROR + HIGHER_ACCESS_REQUIRED - Higher access is required. An
685 explanation follows, worded in a form that can be displayed to the user.
686 ERROR + NO_SUCH_USER - The specified recipient does not exist.
689 RINF (read Room INFormation file)
691 Each room has associated with it a text file containing a description of
692 the room, perhaps containing its intended purpose or other important
693 information. The info file for the Lobby> (the system's base room) is
694 often used as a repository for system bulletins and the like.
696 This command, which accepts no arguments, is simply used to read the info
697 file for the current room. It will return LISTING_FOLLOWS followed by
698 the text of the message (always in format type 0) if the request can be
699 honored, or ERROR if no info file exists for the current room (which is
700 often the case). Other error description codes may accompany this result.
702 When should this command be used? This is, of course, up to the discretion
703 of client software authors, but in Citadel it is executed in two situations:
704 the first time the user ever enters a room; and whenever the contents of the
705 file change. The latter can be determined from the result of a GOTO command,
706 which will tell the client whether the file needs to be read (see GOTO above).
709 DELE (DELEte a message)
711 Delete a message from the current room. The one argument that should be
712 passed to this command is the message number of the message to be deleted.
713 The return value will be OK if the message was deleted, or an ERROR code.
716 MOVE (MOVE a message to a different room)
718 Move a message to a different room. The two arguments that should be passed
719 to this command are the message number of the message to be deleted, and the
720 name of the target room. If the operation succeeds, the message will be
721 deleted from the current room and moved to the target room. An ERROR code
722 usually means that either the user does not have permission to perform this
723 operation, or that the target room does not exist.
726 KILL (KILL current room)
728 This command deletes the current room. It accepts a single argument, which
729 should be nonzero to actually delete the room, or zero to merely check
730 whether the room can be deleted.
732 Once the room is deleted, the current room is undefined. It is suggested
733 that client software immediately GOTO another room (usually _BASEROOM_)
734 after this command completes.
736 Possible return codes:
738 OK - room has been deleted (or, if checking only, request is valid).
739 ERROR+NOT_LOGGED_IN - no user is logged in.
740 ERROR+HIGHER_ACCESS_REQUIRED - not enough access to delete rooms.
741 ERROR+NOT_HERE - this room can not be deleted.
744 CRE8 (CRE[ate] a new room)
746 This command is used to create a new room. Like some of the other
747 commands, it provides a mechanism to first check to see if a room can be
748 created before actually executing the command. CRE8 accepts the following
751 0 - Create flag. Set this to 1 to actually create the room. If it is
752 set to 0, the server merely checks that there is a free slot in which to
753 create a new room, and that the user has enough access to create a room. It
754 returns OK if the client should go ahead and prompt the user for more info,
755 or ERROR or ERROR+HIGHER_ACCESS_REQUIRED if the command will not succeed.
756 1 - Name for new room.
757 2 - Access type for new room:
759 1 - Private; can be entered by guessing the room's name
760 2 - Private; can be entered by knowing the name *and* password
761 3 - Private; invitation only (sometimes called "exclusive")
762 3 - Password for new room (if it is a type 2 room)
763 4 - Floor number on which the room should reside (optional, and in server
764 version 4.01 and above only)
766 If the create flag is set to 1, the room is created (unless something
767 went wrong and an ERROR return is sent), and the server returns OK, but
768 the session is **not** automatically sent to that room. The client still
769 must perform a GOTO command to go to the new room.
772 FORG (FORGet the current room)
774 This command is used to forget (zap) the current room. For those not
775 familiar with Citadel, this terminology refers to removing the room from
776 a user's own known rooms list, *not* removing the room itself. After a
777 room is forgotten, it no longer shows up in the user's known room list,
778 but it will exist in the user's forgotten room list, and will return to the
779 known room list if the user goes to the room (in Citadel, this is
780 accomplished by explicitly typing the room's name in a <.G>oto command).
782 The command takes no arguments. If the command cannot execute for any
783 reason, ERROR will be returned. ERROR+NOT_LOGGED_IN or ERROR+NOT_HERE may
784 be returned as they apply.
786 If the command succeeds, OK will be returned. At this point, the current
787 room is **undefined**, and the client software is responsible for taking
788 the user to another room before executing any other room commands (usually
789 this will be _BASEROOM_ since it is always there).
792 MESG (read system MESsaGe)
794 This command is used to display system messages and/or help files. The
795 single argument it accepts is the name of the file to display. IT IS CASE
796 SENSITIVE. Citadel/UX looks for these files first in the "messages"
797 subdirectory and then in the "help" subdirectory.
799 If the file is found, LISTING_FOLLOWS is returned, followed by a pathname
800 to the file being displayed. Then the message is printed, in format type 0
801 (see MSG0 command for more information on this). If the file is not found,
804 There are some "well known" names of system messages which client software
805 may expect most servers to carry:
807 hello - Welcome message, to be displayed before the user logs in.
808 changepw - To be displayed whenever the user is prompted for a new
809 password. Warns about picking guessable passwords and such.
810 register - Should be displayed prior to the user entering registration.
811 Warnings about not getting access if not registered, etc.
812 help - Main system help file.
813 goodbye - System logoff banner; display when user logs off.
814 roomaccess - Information about how public rooms and different types of
815 private rooms function with regards to access.
816 unlisted - Tells users not to choose to be unlisted unless they're
817 really paranoid, and warns that aides can still see
818 unlisted userlog entries.
820 Citadel/UX provides these for the Citadel/UX Unix text client. They are
821 probably not very useful for other clients:
823 mainmenu - Main menu (when in idiot mode).
828 saveopt - Options to save a message, abort, etc.
829 entermsg - Displayed just before a message is entered, when in
833 GNUR (Get Next Unvalidated User)
835 This command shows the name of a user that needs to be validated. If there
836 are no unvalidated users, OK is returned. Otherwise, MORE_DATA is returned
837 along with the name of the first unvalidated user the server finds. All of
838 the usual ERROR codes may be returned as well (for example, if the user is
839 not an Aide and cannot validate users).
841 A typical "Validate New Users" command would keep executing this command,
842 and then validating each user it returns, until it returns OK when all new
843 users have been validated.
846 GREG (Get REGistration for user)
848 This command retrieves the registration info for a user, whose name is the
849 command's sole argument. All the usual error messages can be returned. If
850 the command succeeds, LISTING_FOLLOWS is returned, followed by the user's name
851 (retrieved from the userlog, with the right upper and lower case etc.) The
852 contents of the listing contains one field per line, followed by the usual
853 000 on the last line.
855 The following lines are defined. Others WILL be added in the futre, so all
856 software should be written to read the lines it knows about and then ignore
862 Line 4: Street address or PO Box
863 Line 5: City/town/village/etc.
864 Line 6: State/province/etc.
866 Line 8: Telephone number
868 Line 10: Internet e-mail address
870 Users without Aide privileges may retrieve their own registration using
871 this command. This can be accomplished either by passing the user's own
872 name as the argument, or the string "_SELF_". The command will always
873 succeed when used in this manner, unless no user is logged in.
878 This command is used to validate users. Obviously, it can only be executed
879 by users with Aide level access. It should be passed two parameters: the
880 name of the user to validate, and the desired access level
882 If the command succeeds, OK is returned. The user's access level is changed
883 and the "need validation" bit is cleared. If the command fails for any
884 reason, ERROR, ERROR+NO_SUCH_USER, or ERROR+HIGHER_ACCESS_REQUIRED will be
888 EINF (Enter INFo file for room)
890 Transmit the info file for the current room with this command. EINF uses
891 a boolean flag (1 or 0 as the first and only argument to the command) to
892 determine whether the client actually wishes to transmit a new info file, or
893 is merely checking to see if it has permission to do so.
895 If the command cannot succeed, it returns ERROR.
896 If the client is only checking for permission, and permission will be
897 granted, OK is returned.
898 If the client wishes to transmit the new info file, SEND_LISTING is
899 returned, and the client should transmit the text of the info file, ended
900 by the usual 000 on a line by itself.
905 This is a simple user listing. It always succeeds, returning
906 LISTING_FOLLOWS followed by zero or more user records, 000 terminated. The
907 fields on each line are as follows:
912 4. Date/time of last login (Unix format)
915 7. Password (listed only if the user requesting the list is an Aide)
917 Unlisted entries will also be listed to Aides logged into the server, but
918 not to ordinary users.
921 REGI (send REGIstration)
923 Clients will use this command to transmit a user's registration info. If
924 no user is logged in, ERROR+NOT_LOGGED_IN is returned. Otherwise,
925 SEND_LISTING is returned, and the server will expect the following information
926 (terminated by 000 on a line by itself):
929 Line 2: Street address or PO Box
930 Line 3: City/town/village/etc.
931 Line 4: State/province/etc.
933 Line 6: Telephone number
934 Line 7: e-mail address
937 CHEK (CHEcK various things)
939 When logging in, there are various things that need to be checked. This
940 command will return ERROR+NOT_LOGGED_IN if no user is logged in. Otherwise
941 it returns OK and the following parameters:
943 0: Number of new private messages in Mail>
944 1: Nonzero if the user needs to register
945 2: (Relevant to Aides only) Nonzero if new users require validation
950 This command deletes a file from the room's directory, if there is one. The
951 name of the file to delete is the only parameter to be supplied. Wildcards
952 are not acceptable, and any slashes in the filename will be converted to
953 underscores, to prevent unauthorized access to neighboring directories. The
954 possible return codes are:
956 OK - Command succeeded. The file was deleted.
957 ERROR+NOT_LOGGED_IN - Not logged in.
958 ERROR+HIGHER_ACCESS_REQUIRED - Not an Aide or Room Aide.
959 ERROR+NOT_HERE - There is no directory in this room.
960 ERROR+FILE_NOT_FOUND - Requested file was not found.
965 This command is similar to DELF, except that it moves a file (and its
966 associated file description) to another room. It should be passed two
967 parameters: the name of the file to move, and the name of the room to move
968 the file to. All of the same return codes as DELF may be returned, and also
969 one additional one: ERROR+NO_SUCH_ROOM, which means that the target room
970 does not exist. ERROR+NOT_HERE could also mean that the target room does
971 not have a directory.
974 NETF (NETwork send a File)
976 This command is similar to MOVF, except that it attempts to send a file over
977 the network to another system. It should be passed two parameters: the name
978 of the file to send, and the node name of the system to send it to. All of
979 the same return codes as MOVF may be returned, except for ERROR+NO_SUCH_ROOM.
980 Instead, ERROR+NO_SUCH_SYSTEM may be returned if the name of the target
983 The name of the originating room will be sent along with the file. Most
984 implementations will look for a room with the same name at the receiving end
985 and attempt to place the file there, otherwise it goes into a bit bucket room
986 for miscellaneous files. This is, however, beyond the scope of this document;
987 see elsewhere for more details.
990 RWHO (Read WHO's online)
992 Displays a list of all users connected to the server. No error codes are
993 ever returned. LISTING_FOLLOWS will be returned, followed by zero or more
994 lines containing the following three fields:
996 0 - Session ID. Citadel/UX fills this with the pid of a server program.
998 2 - The name of the room the user is currently in. This field might not
999 be displayed (for example, if the user is in a private room) or it might
1000 contain other information (such as the name of a file the user is
1002 3 - (server v4.03 and above) The name of the host the client is connecting
1003 from, or "localhost" if the client is local.
1004 4 - (server v4.04 and above) Description of the client software being used
1005 5 - The last time, locally to the server, that a command was received from
1006 this client (Note: NOOP's don't count)
1007 6 - The last command received from a client. (NOOP's don't count)
1008 7 - Session flags. These are: + (spoofed address), - (STEALTH mode), *
1009 (posting) and . (idle). (Citserver 5.02 and above)
1011 The listing is terminated, as always, with the string "000" on a line by
1015 OPEN (OPEN a file for download)
1017 This command is used to open a file for downloading. Only one download
1018 file may be open at a time. The only argument to this command is the name
1019 of the file to be opened. The user should already be in the room where the
1020 file resides. Possible return codes are:
1023 ERROR+NOT_HERE (no directory in this room)
1024 ERROR+FILE_NOT_FOUND (could not open the file)
1028 If the file is successfully opened, OK will be returned, along with the
1029 size (in bytes) of the file, and (in version 5.00 and above) the time of last
1033 CLOS (CLOSe the download file)
1035 This command is used to close the download file. It returns OK if the
1036 file was successfully closed, or ERROR if there wasn't any file open in the
1040 READ (READ from the download file)
1042 Two arguments are passed to this command. The first is the starting position
1043 in the download file, and the second is the total number of bytes to be
1044 read. If the operation can be performed, BINARY_FOLLOWS will be returned,
1045 along with the number of bytes to follow. Then, immediately following the
1046 newline, will be that many bytes of binary data. The client *must* read
1047 exactly that number of bytes, otherwise the client and server will get out
1050 If the operation cannot be performed, any of the usual error codes will be
1054 UOPN (OPeN a file for Uploading)
1056 This command is similar to OPEN, except that this one is used when the
1057 client wishes to upload a file to the server. The first argument is the name
1058 of the file to create, and the second argument is a one-line comment
1059 describing the contents of the file. Only one upload file may be open at a
1060 time. Possible return codes are:
1063 ERROR+NOT_HERE (no directory in this room)
1064 ERROR+FILE_NOT_FOUND (a name must be specified)
1065 ERROR (miscellaneous errors)
1066 ERROR+ALREADY_EXISTS (a file with the same name already exists)
1069 If OK is returned, the command has succeeded and writes may be performed.
1072 UCLS (CLoSe the Upload file)
1074 Close the file opened with UOPN. An argument of "1" should be passed to
1075 this command to close and save the file; otherwise, the transfer will be
1076 considered aborted and the file will be deleted. This command returns OK
1077 if the operation succeeded or ERROR if it did not.
1080 WRIT (WRITe to the upload file)
1082 If an upload file is open, this command may be used to write to it. The
1083 argument passed to this command is the number of bytes the client wishes to
1084 transmit. An ERROR code will be returned if the operation cannot be
1087 If the operation can be performed, SEND_BINARY will be returned, followed
1088 by the number of bytes the server is expecting. The client must then transmit
1089 exactly that number of bytes. Note that in the current implementation, the
1090 number of bytes the server is expecting will always be the number of bytes
1091 the client requested to transmit, but the client software should never assume
1092 that this will always happen, in case changes are made later.
1095 QUSR (Query for a USeR)
1097 This command is used to check to see if a particular user exists. The only
1098 argument to this command is the name of the user being searched for. If
1099 the user exists, OK is returned, along with the name of the user in the userlog
1100 (so the client software can learn the correct upper/lower casing of the name
1101 if necessary). If the user does not exist, ERROR+NO_SUCH_USER is returned.
1102 No login or current room is required to utilize this command.
1105 OIMG (Open an IMaGe file)
1107 Open an image (graphics) file for downloading. Once opened, the file can be
1108 read as if it were a download file. This implies that an image and a download
1109 cannot be opened at the same time. OIMG returns the same result codes as OPEN.
1111 All images will be in GIF (Graphics Interchange Format). In the case of
1112 Citadel/UX, the server will convert the supplied filename to all lower case,
1113 append the characters ".gif" to the filename, and look for it in the "images"
1114 subdirectory. As with the MESG command, there are several "well known"
1115 images which are likely to exist on most servers:
1117 hello - "Welcome" graphics to be displayed alongside MESG "hello"
1118 goodbye - Logoff banner graphics to be displayed alongside MESG "goodbye"
1119 background - Background image (usually tiled) for graphical clients
1121 The following "special" image names are defined in Citadel/UX server version
1124 _userpic_ - Picture of a user (send the username as the second argument)
1125 _floorpic_ - A graphical floor label (send the floor number as the second
1126 argument). Clients which request a floor picture will display
1127 the picture *instead* of the floor name.
1128 _roompic_ - A graphic associated with the *current* room. Clients which
1129 request a room picture will display the picture in *addition*
1130 to the room name (i.e. it's used for a room banner, as
1131 opposed to the floor picture's use in a floor listing).
1135 ---------------------------------------------------------------------------
1136 The following commands are available only in Citadel/UX server version 4.01
1138 ---------------------------------------------------------------------------
1140 NETP (authenticate as network session with system NET Password)
1142 This command is used by client software to identify itself as a transport
1143 session for IGnet/Open BBS to BBS networking. It should be called with
1144 two arguments: the node name of the calling system, and the system net
1145 password for the server. If the authentication succeeds, NETP will return
1146 OK, otherwise, it returns ERROR.
1149 NUOP (Network Upload OPen file)
1151 Open a network spool file for uploading. The client must have already
1152 identified itself as a network session using the NETP command. If the command
1153 returns OK, the client may begin transmitting IGnet/Open spool data using
1154 a series of WRIT commands. When a UCLS command is issued, the spooled data
1155 is entered into the BBS if the argument to UCLS is 1 or discarded if the
1156 argument to UCLS is 0. If the client has not authenticated itself with a
1157 NETP command, ERROR+HIGHER_ACCESS_REQUIRED will be returned.
1160 NDOP (Network Download OPen file)
1162 Open a network spool file for downloading. The client must have already
1163 identified itself as a network session using the NETP command. If the command
1164 returns OK, the client may begin receiving IGnet/Open spool data using
1165 a series of READ commands. When a CLOS command is issued, the spooled data
1166 is deleted from the server and may not be read again. If the client has not
1167 authenticated itself with a NETP command, ERROR+HIGHER_ACCESS_REQUIRED will
1171 LFLR (List all known FLooRs)
1173 On systems supporting floors, this command lists all known floors. The
1174 command accepts no parameters. It will return ERROR+NOT_LOGGED_IN if no
1175 user is logged in. Otherwise it returns LISTING_FOLLOWS and a list of
1176 the available floors, each line consisting of three fields:
1178 1. The floor number associated with the floor
1179 2. The name of the floor
1180 3. Reference count (number of rooms on this floor)
1183 CFLR (Create a new FLooR)
1185 This command is used to create a new floor. It should be passed two
1186 arguments: the name of the new floor to be created, and a 1 or 0 depending
1187 on whether the client is actually creating a floor or merely checking to
1188 see if it has permission to create the floor. The user must be logged in
1189 and have Aide privileges to create a floor.
1191 If the command succeeds, it will return OK followed by the floor number
1192 associated with the new floor. Otherwise, it will return ERROR (plus perhaps
1193 HIGHER_ACCESS_REQUIRED, ALREADY_EXISTS, or INVALID_FLOOR_OPERATION)
1194 followed by a description of why the command failed.
1199 This command is used to delete a floor. It should be passed two
1200 argument: the *number* of the floor to be deleted, and a 1 or 0 depending
1201 on whether the client is actually deleting the floor or merely checking to
1202 see if it has permission to delete the floor. The user must be logged in
1203 and have Aide privileges to delete a floor.
1205 Floors that contain rooms may not be deleted. If there are rooms on a floor,
1206 they must be either deleted or moved to different floors first. This implies
1207 that the Main Floor (floor 0) can never be deleted, since Lobby>, Mail>, and
1208 Aide> all reside on the Main Floor and cannot be deleted.
1210 If the command succeeds, it will return OK. Otherwise it will return
1211 ERROR (plus perhaps HIGHER_ACCESS_REQUIRED or INVALID_FLOOR_OPERATION)
1212 followed by a description of why the command failed.
1217 Edit the parameters of a floor. The client may pass one or more parameters
1220 1. The number of the floor to be edited
1221 2. The desired new name
1223 More parameters may be added in the future. Any parameters not passed to
1224 the server will remain unchanged. A minimal command would be EFLR and a
1225 floor number -- which would do nothing. EFLR plus the floor number plus a
1226 floor name would change the floor's name.
1228 If the command succeeds, it will return OK. Otherwise it will return
1229 ERROR (plus perhaps HIGHER_ACCESS_REQUIRED or INVALID_FLOOR_OPERATION)
1231 ---------------------------------------------------------------------------
1232 The following commands are available only in Citadel/UX server version 4.02
1234 ---------------------------------------------------------------------------
1236 IDEN (IDENtify the client software)
1238 The client software has the option to identify itself to the server.
1239 Currently, the server does nothing with this information except to write
1240 it to the syslog to satisfy the system administrator's curiosity. Other
1241 uses might become apparent in the future.
1243 The IDEN command should contain five fields: a developer ID number (same as
1244 the server developer ID numbers in the INFO command -- please obtain one if
1245 you are a new developer), a client ID number (which does not have to be
1246 globally unique - only unique within the domain of the developer number),
1247 a version number, a free-form text string describing the client, and the name
1248 of the host the user is located at.
1250 It is up to the server to determine whether to accept the host name or to
1251 use the host name it has detected itself. Generally, if the client is
1252 running on a trusted host (either localhost or a well-known publically
1253 accessible client) it should use the host name transmitted by IDEN,
1254 otherwise it should use the host name it has detected itself.
1256 IDEN always returns OK, but since that's the only way it ever returns
1257 there's no point in checking the result code.
1259 ---------------------------------------------------------------------------
1260 The following commands are available only in Citadel/UX server version 4.03
1262 ---------------------------------------------------------------------------
1264 IPGM (identify as an Internal ProGraM)
1266 IPGM is a low-level command that should not be used by normal user clients.
1267 It is used for various utilities to communicate with the server on the same
1268 host. For example, the networker (netproc.c) logs onto the server as an
1269 internal program in order to fetch and store messages. Since user clients
1270 do not utilize this command (or any of its companion commands), developers
1271 writing Citadel-compatible servers need not implement it.
1273 The sole argument to IPGM is the system's internal program password. This
1274 password is generated by the setup program and stored in the config file.
1275 Since internal programs have access to the config file, they know the correct
1278 IPGM returns OK for a correct authentication or ERROR otherwise.
1281 CHAT (enter CHAT mode)
1283 This command functions differently from every other command in the system. It
1284 is used to implement multi-user chat. For this to function, a new transfer
1285 mode, called START_CHAT_MODE, is implemented. If a client does not support
1286 chat mode, it should never send a CHAT command!
1288 In chat mode, messages may arrive asynchronously from the server at any
1289 time. The client may send messages at any time. This allows the arrival of
1290 messages without the client having to poll for them. Arriving messages will
1291 be of the form "user|message", where the "user" portion is, of course, the
1292 name of the user sending the message, and "message" is the message text.
1294 Chat mode ends when the server says it ends. The server will signal the end
1295 of chat mode by transmitting "000" on a line by itself. When the client reads
1296 this line, it must immediately exit from chat mode without sending any
1297 further traffic to the server. The next transmission sent to the server
1298 will be a regular server command.
1300 The Citadel/UX server understands the following commands:
1301 /quit - Exit from chat mode (causes the server to do an 000 end)
1302 /who - List users currently in chat
1303 /whobbs - List users currently in chat and on the bbs
1304 /me - Do an irc-style action.
1305 /join - Join a new "room" in which all messages are only heard by
1306 people in that room.
1307 /msg - /msg <user> <msg> will send the msg to <user> only.
1308 /help - Print help information
1309 NOOP - Do nothing (silently)
1311 Any other non-empty string is treated as message text and will be broadcast
1312 to other users currently in chat.
1315 SEXP (Send EXPress messages)
1317 This is one of two commands which implement "express messages" (also known
1318 as "paging"). An express message is a near-real-time message sent from one
1319 logged in user to another. When an express message is sent, it will be
1320 displayed the next time the target user executes a PEXP command.
1322 The SEXP command accepts two arguments: the name of the user to send the
1323 message to, and the text of the message. If the message is successfully
1324 transmitted, OK is returned. If the target user is not logged in or if
1325 anything else goes wrong, ERROR is returned.
1327 In Citadel/UX 5.00 and above, the reserved name "broadcast" may be used
1328 instead of a user name, to broadcast an express message to all users
1329 currently connected to the server.
1331 Do be aware that if an express message is transmitted to a user who is logged
1332 in using a client that does not check for express messages, the message will
1336 PEXP (Print EXPress messages)
1338 This command, called without any arguments, simply dumps out the contents
1339 of any waiting express messages. It returns ERROR if there is a problem,
1340 otherwise it returns LISTING_FOLLOWS followed by all messages.
1342 So how does the client know there are express messages waiting? It could
1343 execute a random PEXP every now and then. Or, it can check the byte in
1344 server return code messages, between the return code and the parameters. In
1345 much the same way as FTP uses "-" to signify a continuation, Citadel uses
1346 an "*" in this position to signify the presence of waiting express messages.
1348 ---------------------------------------------------------------------------
1349 The following commands are available only in Citadel/UX server version 4.10
1351 ---------------------------------------------------------------------------
1353 EBIO (Enter BIOgraphy)
1355 Transmit to the server a free-form text file containing a little bit of
1356 information about the user for other users to browse. This is typically
1357 referred to as a 'bio' online. EBIO returns SEND_LISTING if it succeeds,
1358 after which the client is expected to transmit the file, or any of the usual
1359 ERROR codes if it fails.
1362 RBIO (Read BIOgraphy)
1364 Receive from the server a named user's bio. This command should be passed
1365 a single argument - the name of the user whose bio is requested. RBIO returns
1366 LISTING_FOLLOWS plus the bio file if the user exists and has a bio on file,
1367 ERROR+NO_SUCH_USER if the named user does not exist, or ERROR+FILE_NOT_FOUND
1368 if the user exists but has no bio on file.
1370 ---------------------------------------------------------------------------
1371 The following commands are available only in Citadel/UX server version 4.11
1373 ---------------------------------------------------------------------------
1375 STEL (enter STEaLth mode)
1377 When in "stealth mode," a user will not show up in the "Who is online"
1378 listing (the RWHO server command). Only Aides may use stealth mode. The
1379 STEL command accepts one argument: a 1 indicating that the user wishes to
1380 enter stealth mode, or a 0 indicating that the user wishes to exit stealth
1381 mode. STEL returns OK if the command succeeded, ERROR+NOT_LOGGED_IN if no
1382 user is logged in, or ERROR+HIGHER_ACCESS_REQUIRED if the user is not an Aide.
1384 The STEL command also makes it so a user does not show up in the chat room
1388 LBIO (List users who have BIOs on file)
1390 This command is self-explanatory. Any user who has used EBIO to place a bio
1391 on file is listed. LBIO almost always returns LISTING_FOLLOWS followed by
1392 this listing, unless it experiences an internal error in which case ERROR
1396 MSG2 (read MeSsaGe, mode 2)
1398 MSG2 follows the same calling convention as MSG0. The difference between
1399 the two commands is that MSG2 outputs messages in standard RFC822 format
1400 rather than in Citadel/UX proprietary format.
1402 This command was implemented in order to make various gateway programs
1403 easier to implement, and to provide some sort of multimedia support in the
1404 future. Keep in mind that when this command is used, all messages will be
1405 output in fixed 80-column format.
1407 ---------------------------------------------------------------------------
1408 The following commands are available only in Citadel/UX server version 5.00
1410 ---------------------------------------------------------------------------
1412 MSG3 (read MeSsaGe, mode 3 -- internal command)
1414 MSG3 is for use by internal programs only and should not be utilized by
1415 user-mode clients. It does require IPGM authentication. MSG3 follows the
1416 same calling convention as the other MSG commands, but upon success returns
1417 BINARY_FOLLOWS followed by a data block containing the _raw_ message format
1421 ENT3 (ENTer message, mode 3 -- internal command)
1423 ENT3 is for use by internal programs only and should not be utilized by
1424 user-mode clients. It does require IPGM authentication. This command posts
1425 a raw message straight into the message base without modification or performing
1426 any checks. It accepts the following arguments:
1428 0 - Post flag. This should be set to 1 to post a message. If it is
1429 set to 0, the server only returns OK or ERROR (plus any flags describing
1430 the error) without reading in a message. This is used to verify the operation
1431 before actually transmitting a message.
1432 1 - Recipient. This argument is utilized only for private mail messages.
1433 It is ignored for public messages. It contains, of course, the name of the
1434 recipient of the message.
1435 2 - The size (in bytes) of the message to be transmitted.
1437 ENT3 returns OK to tell the client that a message can be posted, ERROR if
1438 there would be a problem with the operation, or SEND_BINARY followed by a byte
1439 count if it is expecting the message to be transmitted.
1442 TERM (TERMinate another session)
1444 In a multithreaded environment, it sometimes becomes necessary to terminate
1445 a session that is unusable for whatever reason. The TERM command performs
1446 this task. Naturally, only Aides can execute TERM. The command should be
1447 called with a single argument: the session ID (obtained from an RWHO command)
1448 of the session to be terminated.
1450 TERM returns OK if the session was terminated, or ERROR otherwise. Note that
1451 a client program is prohibited from terminating the session it is currently
1455 NSET (Network SETup commands)
1457 Aides may use this command to configure the networker. This command's
1458 parameters are passed directly to the 'netsetup' command line utility. If
1459 netsetup returns a non-zero exit code, ERROR is returned, along with the
1460 error message (if any). If netsetup returns a zero (success) exit code,
1461 LISTING_FOLLOWS is returned, followed by zero or more lines of output (since
1462 netsetup may have information to display, such as a room or node list) and
1463 the usual '000' listing terminator.
1466 DOWN (shut DOWN the server)
1468 This command, which may only be executed by an Aide, immediately shuts down
1469 the server. It is only implemented on servers on which such an operation is
1470 possible, such as a multithreaded Citadel engine. The server does not restart.
1471 DOWN returns OK if the user is allowed to shut down the server, in which case
1472 the client program should expect the connection to be immediately broken.
1475 SCDN (Schedule or Cancel a shutDowN)
1477 SCDN sets or clears the "scheduled shutdown" flag. Pass this command a 1 or
1478 0 to respectively set or clear the flag. When the "scheduled shutdown" flag is
1479 set, the server will be shut down when there are no longer any users logged in.
1480 Any value other than 0 or 1 will not change the flag, only report its state.
1481 No users will be kicked off the system, and in fact the server is still available
1482 for new connections. The command returns ERROR if it fails; otherwise, it
1483 returns OK followed by a number representing the current state of the flag.
1486 EMSG (Enter a system MeSsaGe)
1488 This is the opposite of the MESG command - it allows the creation and editing
1489 of system messages. The only argument passed to EMSG is the name of the
1490 file being transmitted. If the file exists in any system message directory
1491 on the server it will be overwritten, otherwise a new file is created. EMSG
1492 returns SEND_LISTING on success or ERROR+HIGHER_ACCESS_REQUIRED if the user
1495 Typical client software would use MESG to retrieve any existing message into
1496 an edit buffer, then present an editor to the user and run EMSG if the changes
1500 UIMG (Upload an IMaGe file)
1502 UIMG is complemenary to OIMG; it is used to upload an image to the server.
1503 The first parameter supplied to UIMG should be 0 if the client is only checking
1504 for permission to upload, or 1 if the client is actually attempting to begin
1505 the upload operation. The second argument is the name of the file to be
1506 transmitted. In Citadel/UX, the filename is converted to all lower case,
1507 appended with the characters ".gif", and stored in the "images" directory.
1509 UIMG returns OK if the client has permission to perform the requested upload,
1510 or ERROR+HIGHER_ACCESS_REQUIRED otherwise. If the client requested to begin
1511 the operation (first parameter set to 1), an upload file is opened, and the
1512 client should begin writing to it with WRIT commands, then close it with a
1515 The supplied filename should be one of:
1517 -> _userpic_ (Server will attempt to write to the user's online photo)
1518 -> Any of the "well known" filenames described in the writeup for the
1521 ----------------------------------------------
1522 The following are for citserver 5.02 and above
1523 ----------------------------------------------
1525 HCHG (Hostname CHanGe)
1527 HCHG is a command, usable by any user, that allows a user to change their RWHO
1528 host value. This will mask a client's originating hostname from normal
1529 users; access level 6 and higher see an entry right underneath the spoofed
1530 entry listing the actual hostname the user originates from.
1532 The format of an HCHG command is:
1536 If a HCHG command is successful, the value OK (200) is returned.
1539 RCHG (Roomname CHanGe)
1541 RCHG is a command, usable by any user, that allows a user to change their RWHO
1542 room value. This will mask a client's roomname from normal users; access
1543 level 6 and higher see an entry right underneath the spoofed entry listing
1544 the actual room the user is in.
1546 The format of an RCHG command is:
1550 If a RCHG command is successful, the value OK (200) is returned.
1553 UCHG (Username CHanGe)
1555 UCHG is an aide-level command which allows an aide to effectively change their
1556 username. If this value is blank, the user goes into stealth mode (see
1558 will show up as being from the real username in this mode, however. In
1559 addition, the RWHO listing will include both the spoofed and real usernames.
1561 The format of an UCHG command is:
1565 If a UCHG command is successful, the value OK (200) is returned.
1568 TIME (get server local TIME)
1570 TIME returns OK followed by the current time measured in seconds since
1571 00:00:00 GMT, Jan 1, 1970.
1573 This is used in allowing a client to calculate idle times.
1576 ----------------------------------------------
1577 The following are for citserver 5.50 and above
1578 ----------------------------------------------
1580 AGUP (Administrative Get User Parameters)
1581 ASUP (Administrative Set User Parameters)
1583 These commands are only executable by Aides and by server extensions running
1584 at system-level. They are used to get/set any and all parameters relating to
1585 a user account. AGUP requires only one argument: the name of the user in
1586 question. SGUP requires all of the parameters to be set. The parameters are
1587 as follows, and are common to both commands:
1591 2 - Flags (see citadel.h)
1596 7 - Timestamp of last call
1597 8 - Purge time (in days) for this user (or 0 to use system default)
1599 Upon success, AGUP returns OK followed by all these parameters, and ASUP
1600 simply returns OK. If the client has insufficient access to perform the
1601 requested operation, ERROR+HIGHER_ACCESS_REQUIRED is returned. If the
1602 requested user does not exist, ERROR+NO_SUCH_USER is returned.
1606 GPEX (Get Policy for message EXpiration)
1608 Returns the policy of the current room, floor, or site regarding the automatic
1609 purging (expiration) of messages. The following policies are available:
1610 0 - Fall back to the policy of the next higher level. If this is a room,
1611 use the floor's default policy. If this is a floor, use the system
1612 default policy. This is an invalid value for the system policy.
1613 1 - Do not purge messages automatically.
1614 2 - Purge by message count. (Requires a value: number of messages)
1615 3 - Purge by message age. (Requires a value: number of days)
1617 The format of this command is: GPEX <which>
1618 The value of <which> must be one of: "room" "floor" "site"
1620 If successful, GPEX returns OK followed by <policy>|<value>.
1624 SPEX (Set Polict for message EXpiration)
1626 Sets the policy of the current room, floor, or site regarding the automatic
1627 purging (expiration) of messages. See the writeup for the GPEX command for
1628 the list of available policies.
1630 The format of this command is: SPEX <which>|<policy>|<value>
1631 The value of <which> must be one of: "room" "floor" "site"
1633 If successful, GPEX returns OK; otherwise, an ERROR code is returned.
1637 CONF (get or set global CONFiguration options)
1639 Retrieves or sets various system-wide configuration and policy options. This
1640 command is only available to Aides. The sole parameter accepted is a command,
1641 which should be either GET or SET. If the GET command succeeds, CONF will
1642 return LISTING_FOLLOWS followed by the fields described below, one line at a
1643 time. If the SET command succeeds, CONF will return SEND_LISTING and expect
1644 the fields described below, one line at a time (don't worry about other fields
1645 being added in the future; if a 'short' configuration list is sent, the missing
1646 values at the end will be left unchanged on the system). If either command
1647 fails for any reason, ERROR is returned.
1649 The configuration lines are as follows:
1652 2. Fully qualified domain name
1653 3. Human-readable node name
1654 4. Landline telephone number of this system
1655 5. Flag (0 or 1) - creator of private room automatically becomes room aide
1656 6. Server connection idle timeout (in seconds)
1657 7. Initial access level for new users
1658 8. Flag (0 or 1) - require registration for new users
1659 9. Flag (0 or 1) - automatically move Problem User messages to twit room
1660 10. Name of twit room
1661 11. Text of <more> prompt
1662 12. Flag (0 or 1) - restrict access to Internet mail
1663 13. Geographic location of this system
1664 14. Name of the system administrator
1665 15. Number of maximum concurrent sessions allowed on the server
1666 16. Password for server-to-server networking
1667 17. Default purge time (in days) for users
1668 18. Default purge time (in days) for rooms
1672 EXPI (EXPIre system objects)
1674 Begins purge operations for objects which, according to site policy, are
1675 "old" and should be removed. EXPI should be called with one argument, one of:
1677 "messages" (purge old messages out of each room)
1678 "users" (purge old users from the userlog)
1680 EXPI returns OK (probably after a long delay while it does its work) if it
1681 succeeds; otherwise it returns an ERROR code.
1683 This command is probably temporary, until we can work some sort of scheduler
1684 into the system. It is implemented in the serv_expire module.