chiark / gitweb /
Correct documentation for 'revoke'.
[disorder] / doc / disorder_protocol.5.in
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1.\"
2.\" Copyright (C) 2004-2008 Richard Kettlewell
3.\"
4.\" This program is free software: you can redistribute it and/or modify
5.\" it under the terms of the GNU General Public License as published by
6.\" the Free Software Foundation, either version 3 of the License, or
7.\" (at your option) any later version.
8.\"
9.\" This program is distributed in the hope that it will be useful,
10.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
11.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12.\" GNU General Public License for more details.
13.\"
14.\" You should have received a copy of the GNU General Public License
15.\" along with this program. If not, see <http://www.gnu.org/licenses/>.
16.\"
17.TH disorder_protocol 5
18.SH NAME
19disorder_protocol \- DisOrder communication protocol
20.SH DESCRIPTION
21The DisOrder client and server communicate via the protocol described
22in this man page.
23.PP
24The protocol is liable to change without notice.
25You are recommended to check the implementation before believing this document.
26.SH "GENERAL SYNTAX"
27Everything is encoded using UTF-8.
28See
29.B "CHARACTER ENCODING"
30below for more detail on character encoding issues.
31.PP
32Commands and responses consist of a line perhaps followed (depending on the
33command or response) by a body.
34.PP
35The line syntax is the same as described in \fBdisorder_config\fR(5) except
36that comments are prohibited.
37.PP
38Bodies borrow their syntax from RFC821; they consist of zero or more ordinary
39lines, with any initial full stop doubled up, and are terminated by a line
40consisting of a full stop and a line feed.
41.PP
42Commands only have a body if explicitly stated below.
43If they do have a body then the body should always be sent immediately;
44unlike (for instance) the SMTP "DATA" command there is no intermediate step
45where the server asks for the body to be sent.
46.PP
47Replies also only have a body if stated below.
48The presence of a reply body can always be inferred from the response code;
49if the last digit is a 3 then a body is present, otherwise it is not.
50.SH COMMANDS
51Commands always have a command name as the first field of the line; responses
52always have a 3-digit response code as the first field.
53See below for more details about this field.
54.PP
55All commands require the connection to have been already authenticated unless
56stated otherwise.
57If not stated otherwise, the \fBread\fR right is sufficient to execute
58the command.
59.TP
60.B adduser \fIUSERNAME PASSWORD \fR[\fIRIGHTS\fR]
61Create a new user with the given username and password.
62The new user's rights list can be specified; if it is not
63then the \fBdefault_rights\fR setting applies instead.
64Requires the \fBadmin\fR right, and only works on local
65connections.
66.TP
67.B adopt \fIID\fR
68Adopts a randomly picked track, leaving it in a similar state to if it was
69picked by this user. Requires the \fBplay\fR right.
70.TP
71.B allfiles \fIDIRECTORY\fR [\fIREGEXP\fR]
72List all the files and directories in \fIDIRECTORY\fR in a response body.
73If \fIREGEXP\fR is present only matching files and directories are returned.
74.TP
75.B confirm \fICONFIRMATION
76Confirm user registration.
77\fICONFIRMATION\fR is as returned from \fBregister\fR below.
78This command logs the user in.
79The response contains the logged-in username.
80.TP
81.B cookie \fICOOKIE
82Log a user back in using a cookie created with \fBmake\-cookie\fR.
83The response contains the username.
84.TP
85.B deluser \fIUSERNAME
86Delete the named user.
87Requires the \fBadmin\fR right, and only works on local connections.
88.TP
89.B dirs \fIDIRECTORY\fR [\fIREGEXP\fR]
90List all the directories in \fIDIRECTORY\fR in a response body.
91If \fIREGEXP\fR is present only matching directories are returned.
92.TP
93.B disable \fR[\fBnow\fR]
94Disable further playing.
95If the optional \fBnow\fR argument is present then the current track
96is stopped.
97Requires the \fBglobal prefs\fR right.
98.TP
99.B edituser \fIUSERNAME PROPERTY VALUE
100Set a user property.
101With the \fBadmin\fR right any username and property may be specified.
102Otherwise the \fBuserinfo\fR right is required and only the
103\fBemail\fR and \fBpassword\fR properties may be set.
104.IP
105User properties are syntax-checked before setting. For instance \fBemail\fR
106must contain an "@" sign or you will get an error. (Setting an empty value for
107\fBemail\fR is allowed and removes the property.)
108.TP
109.B enable
110Re-enable further playing, and is the opposite of \fBdisable\fR.
111Requires the \fBglobal prefs\fR right.
112.TP
113.B enabled
114Report whether playing is enabled.
115The second field of the response line will be \fByes\fR or \fBno\fR.
116.TP
117.B exists \fITRACK\fR
118Report whether the named track exists.
119The second field of the response line will be \fByes\fR or \fBno\fR.
120.TP
121.B files \fIDIRECTORY\fR [\fIREGEXP\fR]
122List all the files in \fIDIRECTORY\fR in a response body.
123If \fIREGEXP\fR is present only matching files are returned.
124.TP
125.B get \fITRACK\fR \fIPREF\fR
126Gets a preference value.
127On success the second field of the response line will have the value.
128.IP
129If the track or preference do not exist then the response code is 555.
130.TP
131.B get\-global \fIKEY\fR
132Get a global preference.
133.IP
134If the preference does not exist then the response code is 555.
135.TP
136.B length \fITRACK\fR
137Get the length of the track in seconds.
138On success the second field of the response line will have the value.
139.TP
140.B log
141Send event log messages in a response body.
142The command will never terminate.
143Any further data sent to the server will be discarded (explicitly;
144i.e. it will not accumulate in a buffer somewhere).
145.IP
146See \fBEVENT LOG\fR below for more details.
147.TP
148.B make\-cookie
149Returns an opaque string that can be used by the \fBcookie\fR command to log
150this user back in on another connection (until the cookie expires).
151.TP
152.B move \fITRACK\fR \fIDELTA\fR
153Move a track in the queue.
154The track may be identified by ID (preferred) or name (which might cause
155confusion if it's there twice).
156\fIDELTA\fR should be an negative or positive integer and indicates how
157many steps towards the head of the queue the track should be moved.
158.IP
159Requires one of the \fBmove mine\fR, \fBmove random\fR or \fBmove any\fR rights
160depending on how the track came to be added to the queue.
161.TP
162.B moveafter \fITARGET\fR \fIID\fR ...
163Move all the tracks in the \fIID\fR list after ID \fITARGET\fR.
164If \fITARGET\fR is the empty string then the listed tracks are put
165at the head of the queue.
166If \fITARGET\fR is listed in the ID list then the tracks are moved
167to just after the first non-listed track before it, or to the head if there is
168no such track.
169.IP
170Requires one of the \fBmove mine\fR, \fBmove random\fR or \fBmove any\fR rights
171depending on how the tracks came to be added to the queue.
172.TP
173.B new \fR[\fIMAX\fR]
174Send the most recently added \fIMAX\fR tracks in a response body.
175If the argument is omitted, the \fBnew_max\fR most recent tracks are
176listed (see \fBdisorder_config\fR(5)).
177.TP
178.B nop
179Do nothing.
180Used by
181.BR disobedience (1)
182as a keepalive measure.
183This command does not require authentication.
184.TP
185.B part \fITRACK\fR \fICONTEXT\fI \fIPART\fR
186Get a track name part.
187Returns an empty string if a name part cannot be constructed.
188.IP
189.I CONTEXT
190is one of
191.B sort
192or
193.B display
194and
195.I PART
196is usually one of
197.BR artist ,
198.B album
199or
200.BR title .
201.TP
202.B pause
203Pause the current track.
204Requires the \fBpause\fR right.
205.TP
206.B play \fITRACK\fR
207Add a track to the queue.
208The response contains the queue ID of the track.
209Requires the \fBplay\fR right.
210.TP
211.B playafter \fITARGET\fR \fITRACK\fR ...
212Add all the tracks in the \fITRACK\fR list to the queue after \fITARGET\fR
213(which should be a track ID).
214If \fITARGET\fR is the empty string then the listed tracks are put
215at the head of the queue.
216.IP
217Currently the success result does \fInot\fR include the new track IDs.
218.IP
219Requires the \fBplay\fR right.
220.TP
221.B playing
222Report what track is playing.
223.IP
224If the response is \fB252\fR then the rest of the response line consists of
225track information (see below).
226.IP
227If the response is \fB259\fR then nothing is playing.
228.TP
229.B playlist-delete \fIPLAYLIST\fR
230Delete a playlist.
231Requires permission to modify that playlist and the \fBplay\fR right.
232.TP
233.B playlist-get \fIPLAYLIST\fR
234Get the contents of a playlist, in a response body.
235Requires permission to read that playlist and the \fBread\fR right.
236If the playlist does not exist the response is 555.
237.TP
238.B playlist-get-share \fIPLAYLIST\fR
239Get the sharing status of a playlist.
240The result will be \fBpublic\fR, \fBprivate\fR or \fBshared\fR.
241Requires permission to read that playlist and the \fBread\fR right.
242.TP
243.B playlist-lock \fIPLAYLIST\fR
244Lock a playlist.
245Requires permission to modify that playlist and the \fBplay\fR right.
246Only one playlist may be locked at a time on a given connection and the lock
247automatically expires when the connection is closed.
248.TP
249.B playlist-set \fIPLAYLIST\fR
250Set the contents of a playlist.
251The new contents should be supplied in a command body.
252Requires permission to modify that playlist and the \fBplay\fR right.
253The playlist must be locked.
254.TP
255.B playlist-set-share \fIPLAYLIST\fR \fISHARE\fR
256Set the sharing status of a playlist to
257\fBpublic\fR, \fBprivate\fR or \fBshared\fR.
258Requires permission to modify that playlist and the \fBplay\fR right.
259.TP
260.B playlist-unlock\fR
261Unlock the locked playlist.
262.TP
263.B playlists
264List all playlists that this connection has permission to read.
265Requires the \fBread\fR right.
266.TP
267.B prefs \fBTRACK\fR
268Send back the preferences for \fITRACK\fR in a response body.
269Each line of the response has the usual line syntax, the first field being the
270name of the pref and the second the value.
271.TP
272.B queue
273Send back the current queue in a response body, one track to a line, the track
274at the head of the queue (i.e. next to be be played) first.
275See below for the track information syntax.
276.TP
277.B random\-disable
278Disable random play (but don't stop the current track).
279Requires the \fBglobal prefs\fR right.
280.TP
281.B random\-enable
282Enable random play.
283Requires the \fBglobal prefs\fR right.
284.TP
285.B random\-enabled
286Report whether random play is enabled.
287The second field of the response line will be \fByes\fR or \fBno\fR.
288.TP
289.B recent
290Send back the current recently-played list in a response body, one track to a
291line, the track most recently played last.
292See below for the track information syntax.
293.TP
294.B reconfigure
295Request that DisOrder reconfigure itself.
296Requires the \fBadmin\fR right.
297.IP
298Not all configuration options can be modified during the lifetime of the
299server; of those that can't, some will just be ignored if they change while
300others will cause the new configuration to be rejected.
301See \fBdisorder_config\fR(5) for details.
302.TP
303.B register \fIUSERNAME PASSWORD EMAIL
304Register a new user.
305Requires the \fBregister\fR right.
306The result contains a confirmation string; the user will be be able
307to log in until this has been presented back to the server via the
308\fBconfirm\fR command.
309.TP
310.B reminder \fIUSERNAME\fR
311Send a password reminder to user \fIUSERNAME\fR.
312If the user has no valid email address, or no password, or a
313reminder has been sent too recently, then no reminder will be sent.
314.TP
315.B remove \fIID\fR
316Remove the track identified by \fIID\fR.
317Requires one of the \fBremove mine\fR, \fBremove random\fR or
318\fBremove any\fR rights depending on how the
319track came to be added to the queue.
320.TP
321.B rescan \fR[\fBwait\fR] \fR[\fBfresh\fR]
322Rescan all roots for new or obsolete tracks.
323Requires the \fBrescan\fR right.
324.IP
325If the \fBwait\fR flag is present then the response is delayed until the rescan
326completes.
327Otherwise the response arrives immediately.
328This is primarily intended for testing.
329.IP
330If the \fBfresh\fR flag is present a rescan is already underway then a second
331rescan will be started when it completes.
332The default behavior is to piggyback on the existing rescan.
333.IP
334NB that \fBfresh\fR is currently disabled in the server source, so using this
335flag will just provoke an error.
336.TP
337.B resolve \fITRACK\fR
338Resolve a track name, i.e. if this is an alias then return the real track name.
339.TP
340.B resume
341Resume the current track after a \fBpause\fR command.
342Requires the \fBpause\fR right.
343.TP
344.B revoke
345Revoke the current login's cookie.
346It will not be possible to use the cookie in the future.
347.TP
348.B rtp\-address
349Report the RTP broadcast (or multicast) address, in the form \fIADDRESS
350PORT\fR.
351This command does not require authentication.
352.TP
353.B scratch \fR[\fIID\fR]
354Remove the track identified by \fIID\fR, or the currently playing track if no
355\fIID\fR is specified.
356Requires one of the \fBscratch mine\fR, \fBscratch random\fR or
357\fBscratch any\fR rights depending on how the track came to be
358added to the queue.
359.TP
360.B schedule-add \fIWHEN\fR \fIPRIORITY\fR \fIACTION\fR ...
361Schedule an event for the future.
362.IP
363.I WHEN
364is the time when it should happen, as \fBtime_t\fR value.
365It must refer to a time in the future.
366.IP
367.I PRIORITY
368is the event priority.
369This can be \fBnormal\fR, in which case the event will be run at startup if its
370time has past, or \fBjunk\fR in which case it will be discarded if it is found
371to be in the past at startup.
372The meaning of other values is not defined.
373.IP
374.I ACTION
375is the action to perform.
376The choice of action determines the meaning of the remaining arguments.
377Possible actions are:
378.RS
379.TP
380.B play
381Play a track.
382The next argument is the track name.
383Requires the \fBplay\fR right.
384.TP
385.B set-global
386Set a global preference.
387The next argument is the preference name and the final argument is the value to
388set it to (omit it to unset it).
389Requires the \fBglobal prefs\fR right.
390.RE
391.IP
392You need the right at the point you create the event.
393It is not possible to create scheduled events in expectation of a future change
394in rights.
395.TP
396.B schedule-del \fIEVENT\fR
397Deletes a scheduled event.
398Users can always delete their own scheduled events; with the \fBadmin\fR
399right you can delete any event.
400.TP
401.B schedule-get \fIEVENT\fR
402Sends the details of scheduled event \fIEVENT\fR in a response body.
403Each line is a pair of strings quoted in the usual way, the first being the key
404ane the second the value.
405No particular order is used.
406.IP
407Scheduled events are considered public information.
408Right \fBread\fR is sufficient to see details of all events.
409.TP
410.B schedule-list
411Sends the event IDs of all scheduled events in a response body, in no
412particular order.
413Use \fBschedule-get\fR to get the details of each event.
414.TP
415.B search \fITERMS\fR
416Search for tracks matching the search terms.
417The results are put in a response body, one to a line.
418.IP
419The search string is split in the usual way, with quoting supported, into a
420list of terms.
421Only tracks matching all terms are included in the results.
422.IP
423Any terms of the form \fBtag:\fITAG\fR limits the search to tracks with that
424tag.
425.IP
426All other terms are interpreted as individual words which must be present in
427the track name.
428.IP
429Spaces in terms don't currently make sense, but may one day be interpreted to
430allow searching for phrases.
431.TP
432.B \fBset\fR \fITRACK\fR \fIPREF\fR \fIVALUE\fR
433Set a preference.
434Requires the \fBprefs\fR right.
435.TP
436.B set\-global \fIKEY\fR \fIVALUE\fR
437Set a global preference.
438Requires the \fBglobal prefs\fR right.
439.TP
440.B shutdown
441Requests server shutdown.
442Requires the \fBadmin\fR right.
443.TP
444.B stats
445Send server statistics in plain text in a response body.
446.TP
447.B \fBtags\fR
448Send the list of currently known tags in a response body.
449.TP
450.B \fBunset\fR \fITRACK\fR \fIPREF\fR
451Unset a preference.
452Requires the \fBprefs\fR right.
453.TP
454.B \fBunset\-global\fR \fIKEY\fR
455Unset a global preference.
456Requires the \fBglobal prefs\fR right.
457.TP
458.B user \fIUSERNAME\fR \fIRESPONSE\fR
459Authenticate as user \fIUSERNAME\fR.
460See
461.B AUTHENTICATION
462below.
463.TP
464.B userinfo \fIUSERNAME PROPERTY
465Get a user property.
466.TP
467.B users
468Send the list of currently known users in a response body.
469.TP
470.B version
471Send back a response with the server version as the second field.
472.TP
473.B volume \fR[\fILEFT\fR [\fIRIGHT\fR]]
474Get or set the volume.
475.IP
476With zero parameters just gets the volume and reports the left and right sides
477as the 2nd and 3rd fields of the response.
478.IP
479With one parameter sets both sides to the same value.
480With two parameters sets each side independently.
481Setting the volume requires the \fBvolume\fR right.
482.SH RESPONSES
483Responses are three-digit codes.
484The first digit distinguishes errors from successful responses:
485.TP
486.B 2
487Operation succeeded.
488.TP
489.B 5
490Operation failed.
491.PP
492The second digit breaks down the origin of the response:
493.TP
494.B 0
495Generic responses not specific to the handling of the command.
496Mostly this is parse errors.
497.TP
498.B 1
49951x errors indicate that the user had insufficient rights for the command.
500.TP
501.B 3
502Authentication responses.
503.TP
504.B 5
505Responses specific to the handling of the command.
506.PP
507The third digit provides extra information about the response:
508.TP
509.B 0
510Text part is just commentary.
511.TP
512.B 1
513Text part is a constant result e.g. \fBversion\fR.
514.TP
515.B 2
516Text part is a potentially variable result.
517.TP
518.B 3
519Text part is just commentary; a dot-stuffed body follows.
520.TP
521.B 4
522Text part is just commentary; an indefinite dot-stuffed body follows.
523(Used for \fBlog\fR.)
524.TP
525.B 5
526Used with "normal" errors, for instance a preference not being found.
527The text part is commentary.
528.TP
529.B 9
530The text part is just commentary (but would normally be a response for this
531command) e.g. \fBplaying\fR.
532.PP
533Result strings (not bodies) intended for machine parsing (i.e. xx1 and xx2
534responses) are quoted.
535.SH AUTHENTICATION
536When a connection is made the server sends a \fB231\fR response before any
537command is received.
538This contains a protocol generation, an algorithm name and a
539challenge encoded in hex, all separated by whitespace.
540.PP
541The current protocol generation is \fB2\fR.
542.PP
543The possible algorithms are (currently) \fBsha1\fR, \fBsha256\fR, \fBsha384\fR
544and \fBsha512\fR.
545\fBSHA1\fR etc work as synonyms.
546.PP
547The \fBuser\fR response consists of the selected hash of the user's password
548concatenated with the challenge, encoded in hex.
549.SH "TRACK INFORMATION"
550Track information is encoded in a line (i.e. using the usual line syntax) as
551pairs of fields.
552The first is a name, the second a value.
553The names have the following meanings:
554.TP 12
555.B expected
556The time the track is expected to be played at.
557.TP
558.B id
559A string uniquely identifying this queue entry.
560.TP
561.B played
562The time the track was played at.
563.TP
564.B scratched
565The user that scratched the track.
566.TP
567.B origin
568The origin of the track. Valid origins are:
569.RS
570.TP 12
571.B adopted
572The track was originally randomly picked but has been adopted by a user.
573.TP
574.B picked
575The track was picked by a user.
576.TP
577.B random
578The track was randomly picked.
579.TP
580.B scheduled
581The track was played from a scheduled action.
582.TP
583.B scratch
584The track is a scratch sound.
585.RE
586.TP
587.B state
588The current track state.
589Valid states are:
590.RS
591.TP 12
592.B failed
593The player failed (exited with nonzero status but wasn't scratched).
594.TP
595.B ok
596The track was played without any problems.
597.TP
598.B scratched
599The track was scratched.
600.TP
601.B started
602The track is currently playing.
603.TP
604.B paused
605Track is playing but paused.
606.TP
607.B unplayed
608In the queue, hasn't been played yet.
609.TP
610.B quitting
611The track was terminated because the server is shutting down.
612.RE
613.TP
614.B submitter
615The user that submitted the track.
616.TP
617.B track
618The filename of the track.
619.TP
620.B when
621The time the track was added to the queue.
622.TP
623.B wstat
624The wait status of the player in decimal.
625.PP
626Note that \fBorigin\fR is new with DisOrder 4.3, and obsoletes some old
627\fBstate\fR values.
628.SH NOTES
629Times are decimal integers using the server's \fBtime_t\fR.
630.PP
631For file listings, the regexp applies to the basename of the returned file, not
632the whole filename, and letter case is ignored.
633\fBpcrepattern\fR(3) describes the regexp syntax.
634.PP
635Filenames are in UTF-8 even if the collection they come from uses some other
636encoding - if you want to access the real file (in such cases as the filenames
637actually correspond to a real file) you'll have to convert to whatever the
638right encoding is.
639.SH "EVENT LOG"
640The event log consists of lines starting with a hexadecimal timestamp and a
641keyword followed by (optionally) parameters.
642The parameters are quoted in the usual DisOrder way.
643Currently the following keywords are used:
644.TP
645.B adopted \fIID\fR \fIUSERNAME\fR
646\fIUSERNAME\fR adopted track \fIID\fR.
647.TP
648.B completed \fITRACK\fR
649Completed playing \fITRACK\fR
650.TP
651.B failed \fITRACK\fR \fIERROR\fR
652Completed playing \fITRACK\fR with an error status
653.TP
654.B global_pref \fIPREF\fR [\fIVALUE\fR]
655A global preference was set or unset.
656.TP
657.B moved \fIUSERNAME\fR
658User \fIUSERNAME\fR moved some track(s).
659Further details aren't included any more.
660.TP
661.B playing \fITRACK\fR [\fIUSERNAME\fR]
662Started playing \fITRACK\fR.
663.TP
664.B playlist_created \fIPLAYLIST\fR \fISHARING\fR
665Sent when a playlist is created.
666For private playlists this is intended to be sent only to the owner (but
667this is not currently implemented).
668.TP
669.B playlist_deleted \fIPLAYLIST\fR
670Sent when a playlist is deleted.
671For private playlists this is intended to be sent only to the owner (but
672this is not currently implemented).
673.TP
674.B playlist_modified \fIPLAYLIST\fR \fISHARING\fR
675Sent when a playlist is modified (either its contents or its sharing status).
676For private playlists this is intended to be sent only to the owner (but
677this is not currently implemented).
678.TP
679.B queue \fIQUEUE-ENTRY\fR...
680Added \fITRACK\fR to the queue.
681.TP
682.B recent_added \fIQUEUE-ENTRY\fR...
683Added \fIID\fR to the recently played list.
684.TP
685.B recent_removed \fIID\fR
686Removed \fIID\fR from the recently played list.
687.TP
688.B removed \fIID\fR [\fIUSERNAME\fR]
689Queue entry \fIID\fR was removed.
690This is used both for explicit removal (when \fIUSERNAME\fR is present)
691and when playing a track (when it is absent).
692.TP
693.B rescanned
694A rescan completed.
695.TP
696.B scratched \fITRACK\fR \fIUSERNAME\fR
697\fITRACK\fR was scratched by \fIUSERNAME\fR.
698.TP
699.B state \fIKEYWORD\fR
700Some state change occurred.
701The current set of keywords is:
702.RS
703.TP
704.B completed
705The current track completed successfully.
706.TP
707.B disable_play
708Playing was disabled.
709.TP
710.B disable_random
711Random play was disabled.
712.TP
713.B enable_play
714Playing was enabled.
715.TP
716.B enable_random
717Random play was enabled.
718.TP
719.B failed
720The current track failed.
721.TP
722.B pause
723The current track was paused.
724.TP
725.B playing
726A track started playing.
727.TP
728.B resume
729The current track was resumed.
730.TP
731.B rights_changed \fIRIGHTS\fR
732User's rights were changed.
733.TP
734.B scratched
735The current track was scratched.
736.PP
737To simplify client implementation, \fBstate\fR commands reflecting the current
738state are sent at the start of the log.
739.RE
740.TP
741.B user_add \fIUSERNAME\fR
742A user was created.
743.TP
744.B user_delete \fIUSERNAME\fR
745A user was deleted.
746.TP
747.B user_edit \fIUSERNAME\fR \fIPROPERTY\fR
748Some property of a user was edited.
749.TP
750.B user_confirm \fIUSERNAME\fR
751A user's login was confirmed (via the web interface).
752.TP
753.B volume \fILEFT\fR \fIRIGHT\fR
754The volume changed.
755.PP
756.IR QUEUE-ENTRY ...
757is as defined in
758.B "TRACK INFORMATION"
759above.
760.PP
761The \fBuser-*\fR messages are only sent to admin users, and are not sent over
762non-local connections unless \fBremote_userman\fR is enabled.
763.SH "CHARACTER ENCODING"
764All data sent by both server and client is encoded using UTF-8.
765Moreover it must be valid UTF-8, i.e. non-minimal sequences are not
766permitted, nor are surrogates, nor are code points outside the
767Unicode code space.
768.PP
769There are no particular normalization requirements on either side of the
770protocol.
771The server currently converts internally to NFC, the client must
772normalize the responses returned if it needs some normalized form for further
773processing.
774.PP
775The various characters which divide up lines may not be followed by combining
776characters.
777For instance all of the following are prohibited:
778.TP
779.B o
780LINE FEED followed by a combining character.
781For example the sequence LINE FEED, COMBINING GRAVE ACCENT is never permitted.
782.TP
783.B o
784APOSTROPHE or QUOTATION MARK followed by a combining character when used to
785delimit fields.
786For instance a line starting APOSTROPHE, COMBINING CEDILLA is prohibited.
787.IP
788Note that such sequences are not prohibited when the quote character cannot be
789interpreted as a field delimiter.
790For instance APOSTROPHE, REVERSE SOLIDUS, APOSTROPHE, COMBINING CEDILLA,
791APOSTROPHE would be permitted.
792.TP
793.B o
794REVERSE SOLIDUS (BACKSLASH) followed by a combining character in a quoted
795string when it is the first character of an escape sequence.
796For instance a line starting APOSTROPHE, REVERSE SOLIDUS, COMBINING TILDE
797is prohibited.
798.IP
799As above such sequences are not prohibited when the character is not being used
800to start an escape sequence.
801For instance APOSTROPHE, REVERSE SOLIDUS, REVERSE SOLIDS, COMBINING TILDE,
802APOSTROPHE is permitted.
803.TP
804.B o
805Any of the field-splitting whitespace characters followed by a combining
806character when not part of a quoted field.
807For instance a line starting COLON, SPACE, COMBINING CANDRABINDU is prohibited.
808.IP
809As above non-delimiter uses are fine.
810.TP
811.B o
812The FULL STOP characters used to quote or delimit a body.
813.PP
814Furthermore none of these characters are permitted to appear in the context of
815a canonical decomposition (i.e. they must still be present when converted to
816NFC).
817In practice however this is not an issue in Unicode 5.0.
818.PP
819These rules are consistent with the observation that the split() function is
820essentially a naive ASCII parser.
821The implication is not that these sequences never actually appear in
822the protocol, merely that the server is not required to honor them in
823any useful way nor be consistent between versions: in current
824versions the result will be lines and fields that start with combining
825characters and are not necessarily split where you expect, but future versions
826may remove them, reject them or ignore some or all of the delimiters that have
827following combining characters, and no notice will be given of any change.
828.SH "SEE ALSO"
829\fBdisorder\fR(1),
830\fBtime\fR(2),
831\fBdisorder\fR(3),
832\fBpcrepattern\fR(3)
833\fBdisorder_config\fR(5),
834\fBdisorderd\fR(8),
835\fButf8\fR(7)
836.\" Local Variables:
837.\" mode:nroff
838.\" fill-column:79
839.\" End: