bin/disorder-notify: Don't fork on an explicit `watch' request.
[profile] / bin / disorder-notify
1 #! /usr/bin/perl -w
2
3 use autodie qw{:all};
4 use strict;
5
6 use DisOrder;
7 use File::FcntlLock;
8 use POSIX qw{:errno_h :fcntl_h};
9
10 ###--------------------------------------------------------------------------
11 ### Configuration.
12
13 my %C = (config => "$ENV{HOME}/.disorder/passwd",
14 lockdir => "$ENV{HOME}/.disorder/",
15 mixer => "Master,0");
16
17 my $TITLE = "DisOrder";
18 my $VARIANT = "default";
19 if (-l $C{config} && (my $t = readlink $C{config}) =~ /^passwd\.(.*)$/)
20 { $VARIANT = $1; $TITLE .= " ($1)"; }
21
22 ###--------------------------------------------------------------------------
23 ### Random utilities.
24
25 sub run_discard_output (@) {
26 my $kid = fork();
27 if (!$kid) {
28 open STDOUT, ">/dev/null" or die "open /dev/null: $!";
29 exec @_;
30 }
31 waitpid $kid, 0;
32 if ($?) {
33 my $st;
34 if ($? >= 256) { $st = sprintf "rc = %d", $? >> 8; }
35 else { $st = sprintf "signal %d", $?; }
36 die "$_[0] failed ($st)";
37 }
38 }
39
40 sub notify ($$) {
41 my ($head, $body) = @_;
42
43 $body =~ s:\&:&:g;
44 $body =~ s:\<:&lt;:g;
45 $body =~ s:\>:&gt;:g;
46
47 ##print "****************\n$head\n\n$body\n"; return;
48
49 run_discard_output "notify-send",
50 "-c", "DisOrder", "-i", "audio-volume-high", "-t", "5000",
51 $head, $body;
52 }
53
54 sub try_unlink ($) {
55 my ($f) = @_;
56 eval { unlink $f; };
57 die $@ if $@ and $@->errno != ENOENT;
58 }
59
60 ###--------------------------------------------------------------------------
61 ### Locking protocol.
62
63 my $LKFILE = "$C{lockdir}/disorder-notify-$VARIANT.lock";
64 my $LKFH;
65
66 sub locked_by () {
67
68 ## Try to open the lock file. If it's not there, then obviously it's not
69 ## locked.
70 my $fh;
71 eval { open $fh, "<", $LKFILE; };
72 if ($@) {
73 return undef if $@->errno == ENOENT;
74 die $@;
75 }
76
77 ## Take out a non-exclusive lock on the lock file.
78 my $lk = new File::FcntlLock;
79 $lk->l_type(F_RDLCK); $lk->l_whence(SEEK_SET);
80 $lk->l_start(0); $lk->l_len(0);
81 if ($lk->lock($fh, F_SETLK)) { close $fh; return undef; }
82
83 ## Read the pid of the current lock-holder.
84 chomp (my $pid = (readline $fh) // "<unknown>");
85 close $fh;
86 return $pid;
87 }
88
89 sub claim_lock () {
90 sysopen my $fh, $LKFILE, O_CREAT | O_WRONLY;
91
92 my $lk = new File::FcntlLock;
93 $lk->l_type(F_WRLCK); $lk->l_whence(SEEK_SET);
94 $lk->l_start(0); $lk->l_len(0);
95 if (!$lk->lock($fh, F_SETLK)) {
96 return undef if $! == EAGAIN;
97 die "failed to lock `$LKFILE': $!";
98 }
99
100 truncate $fh, 0;
101 print $fh "$$\n";
102 flush $fh;
103 $LKFH = $fh;
104 1;
105 }
106
107 ###--------------------------------------------------------------------------
108 ### DisOrder utilities.
109
110 sub get_state0 ($) {
111 my ($sk) = @_;
112 my %st = ();
113
114 LINE: for (;;) {
115 my @f = split_fields readline $sk;
116 if ($f[1] ne "state") { last LINE; }
117 elsif ($f[2] eq "enable_random") { $st{random} = 1; }
118 elsif ($f[2] eq "disable_random") { $st{random} = 0; }
119 elsif ($f[2] eq "enable_play") { $st{play} = 1; }
120 elsif ($f[2] eq "disable_play") { $st{play} = 0; }
121 elsif ($f[2] eq "resume") { $st{pause} = 0; }
122 elsif ($f[2] eq "pause") { $st{pause} = 1; }
123 }
124 return \%st;
125 }
126
127 sub get_state () {
128 my $sk = connect_to_server $C{config};
129 send_command0 $sk, "log";
130 my $st = get_state0 $sk;
131 close $sk;
132 return $st;
133 }
134
135 sub decode_track_name ($\%) {
136 my ($sk, $info) = @_;
137 return unless exists $info->{track};
138 my $track = $info->{track};
139 for my $i ("artist", "album", "title") {
140 my @f = split_fields send_command $sk, "part", $track, "display", "$i";
141 $info->{$i} = $f[0];
142 }
143 }
144
145 sub fmt_duration ($) {
146 my ($n) = @_;
147 return sprintf "%d:%02d", int $n/60, $n%60;
148 }
149
150 sub format_now_playing (\%) {
151 my ($info) = @_;
152 exists $info->{track} or return "Nothing.";
153 my $r = "$info->{artist}: ‘$info->{title}’";
154 $r .= ", from ‘$info->{album}’" if $info->{album};
155 exists $info->{sofar} && exists $info->{length} and
156 $r .= sprintf " (%s/%s)",
157 fmt_duration $info->{sofar}, fmt_duration $info->{length};
158 $r .= "\n(chosen by $info->{submitter})" if exists $info->{submitter};
159 return $r;
160 }
161
162 sub get_now_playing ($) {
163 my ($sk) = @_;
164 my $r = send_command $sk, "playing";
165 defined $r or return {};
166 my %info = split_fields $r;
167 decode_track_name $sk, %info;
168 exists $info{sofar} and
169 $info{length} = send_command $sk, "length", $info{track};
170 return \%info;
171 }
172
173 sub watch_and_notify0 ($) {
174 my ($now_playing) = @_;
175
176 my $sk = connect_to_server $C{config}, 1;
177 my $sk_log = connect_to_server $C{config}, 1;
178
179 send_command0 $sk_log, "log";
180 my $st = get_state0 $sk_log;
181 my $msg = "playing " . ($st->{play} ? "enabled" : "disabled");
182 $msg .= "; random play " . ($st->{random} ? "enabled" : "disabled");
183 $msg .= "; " . ($st->{pause} ? "paused" : "playing");
184 notify "$TITLE state", "Connected: $msg";
185 if ($st->{play} && $now_playing) {
186 my $info = get_now_playing $sk;
187 notify "$TITLE: Now playing", format_now_playing %$info;
188 }
189
190 while (my $line = readline $sk_log) {
191 my @f = split_fields $line;
192
193 if ($f[1] eq "state") {
194 my $msg = undef;
195 if ($f[2] eq "disable_random") { $msg = "Random play disabled"; }
196 elsif ($f[2] eq "enable_random") { $msg = "Random play enabled"; }
197 elsif ($f[2] eq "disable_play") { $msg = "Playing disabled"; }
198 elsif ($f[2] eq "enable_play") { $msg = "Playing enabled"; }
199 elsif ($f[2] eq "pause") { $msg = "Paused"; }
200 elsif ($f[2] eq "resume") { $msg = "Playing"; }
201 notify "$TITLE state", $msg if defined $msg;
202 } elsif ($f[1] eq "playing") {
203 my %info;
204 $info{track} = $f[2];
205 $info{submitter} = $f[3] if @f > 3;
206 decode_track_name $sk, %info;
207 notify "$TITLE: Now playing", format_now_playing %info;
208 } elsif ($f[1] eq "scratched") {
209 my %info;
210 $info{track} = $f[2];
211 decode_track_name $sk, %info;
212 notify "$TITLE: Scratched by $f[3]", format_now_playing %info;
213 }
214 }
215
216 notify "$TITLE state", "Lost connection";
217
218 close $sk;
219 close $sk_log;
220 }
221
222 sub watch_and_notify ($) {
223 my ($now_playing) = @_;
224
225 claim_lock or exit 1;
226
227 for (;;) {
228 eval { watch_and_notify0 $now_playing; };
229 $now_playing = 1;
230 sleep 5;
231 }
232 }
233
234 ###--------------------------------------------------------------------------
235 ### User-facing operations.
236
237 my %OP;
238
239 $OP{"volume-up"} =
240 sub { run_discard_output "amixer", "sset", $C{mixer}, "5\%+"; };
241 $OP{"volume-down"} =
242 sub { run_discard_output "amixer", "sset", $C{mixer}, "5\%-"; };
243
244 $OP{"scratch"} = sub {
245 my $sk = connect_to_server $C{config};
246 send_command $sk, "scratch";
247 close $sk;
248 };
249
250 $OP{"enable/disable"} = sub {
251 my $st = get_state;
252 my $sk = connect_to_server $C{config};
253 if ($st->{play}) { send_command $sk, "disable"; }
254 else { send_command $sk, "enable"; }
255 close $sk;
256 };
257
258 $OP{"play/pause"} = sub {
259 my $st = get_state;
260 my $sk = connect_to_server $C{config};
261 if (!$st->{play}) {
262 send_command $sk, "enable";
263 if ($st->{pause}) { send_command $sk, "resume"; }
264 } else {
265 if ($st->{pause}) { send_command $sk, "resume"; }
266 else { send_command $sk, "pause"; }
267 }
268 close $sk;
269 };
270
271 $OP{"watch"} = sub {
272 if (defined (my $lkpid = locked_by)) {
273 print STDERR "$0: already watched by pid $lkpid\n";
274 exit 2;
275 }
276 watch_and_notify 1;
277 };
278
279 $OP{"now-playing"} = sub {
280 my $sk = connect_to_server $C{config};
281 my $info = get_now_playing $sk;
282 close $sk;
283 print format_now_playing %$info;
284 print "\n";
285 };
286
287 $OP{"notify-now-playing"} = sub {
288 my $sk = connect_to_server $C{config};
289 my $info = get_now_playing $sk;
290 close $sk;
291 notify "$TITLE: Now playing", format_now_playing %$info;
292 unless (defined locked_by) {
293 fork and exit 0;
294 watch_and_notify 0;
295 }
296 };
297
298 $OP{"next-config"} = sub {
299 (my $dir = $C{config}) =~ s:/[^/]*$::;
300 my (@conf, $curr, $conf, $min);
301
302 if (-l $C{config} && (my $t = readlink $C{config}) =~ /^passwd\.(.*)$/)
303 { $curr = $1; }
304
305 opendir my $dh, +$dir;
306 FILE: while (my $f = readdir $dh)
307 { push @conf, $1 if $f =~ /^passwd\.(.*[^~])$/; }
308
309 for (my $i = 0; $i < @conf; $i++) {
310 $min = $conf[$i] if (!defined $min) || $conf[$i] lt $min;
311 $conf = $conf[$i]
312 if ((!defined $curr) || $curr lt $conf[$i]) &&
313 ((!defined $conf) || $conf[$i] lt $conf);
314 }
315 $conf = $min unless defined $conf;
316
317 try_unlink "$dir/passwd.new";
318 symlink "passwd.$conf", "$dir/passwd.new";
319 rename "$dir/passwd.new", "$dir/passwd";
320 notify "DisOrder configuration", "Switched to `$conf'";
321 };
322
323 ###--------------------------------------------------------------------------
324 ### Main program.
325
326 if (@ARGV != 1) { print STDERR "usage: $0 OP\n"; exit 2; }
327 my $op = $ARGV[0];
328 if (!exists $OP{$op}) { print STDERR "$0: unknown op `$op'\n"; exit 2; }
329 $OP{$op}();
330
331 ###----- That's all, folks --------------------------------------------------