2 * vim:ts=4:sw=4:expandtab
4 * i3bar - an xcb-based status- and ws-bar for i3
5 * © 2010-2012 Axel Wagner and contributors (see also: LICENSE)
7 * child.c: Getting Input for the statusline
12 #include <sys/types.h>
21 #include <yajl/yajl_common.h>
22 #include <yajl/yajl_parse.h>
23 #include <yajl/yajl_version.h>
24 #include <yajl/yajl_gen.h>
28 /* Global variables for child_*() */
29 i3bar_child child = { 0 };
31 /* stdin- and sigchild-watchers */
35 /* JSON parser for stdin */
36 yajl_callbacks callbacks;
39 /* JSON generator for stdout */
42 typedef struct parser_ctx {
43 /* True if one of the parsed blocks was urgent */
46 /* A copy of the last JSON map key. */
49 /* The current block. Will be filled, then copied and put into the list of
51 struct status_block block;
54 parser_ctx parser_context;
56 /* The buffer statusline points to */
57 struct statusline_head statusline_head = TAILQ_HEAD_INITIALIZER(statusline_head);
58 char *statusline_buffer = NULL;
61 * Stop and free() the stdin- and sigchild-watchers
65 if (stdin_io != NULL) {
66 ev_io_stop(main_loop, stdin_io);
68 FREE(statusline_buffer);
69 /* statusline pointed to memory within statusline_buffer */
73 if (child_sig != NULL) {
74 ev_child_stop(main_loop, child_sig);
78 memset(&child, 0, sizeof(i3bar_child));
82 * The start of a new array is the start of a new status line, so we clear all
86 static int stdin_start_array(void *context) {
87 struct status_block *first;
88 while (!TAILQ_EMPTY(&statusline_head)) {
89 first = TAILQ_FIRST(&statusline_head);
90 I3STRING_FREE(first->full_text);
93 FREE(first->instance);
94 TAILQ_REMOVE(&statusline_head, first, blocks);
101 * The start of a map is the start of a single block of the status line.
104 static int stdin_start_map(void *context) {
105 parser_ctx *ctx = context;
106 memset(&(ctx->block), '\0', sizeof(struct status_block));
108 /* Default width of the separator block. */
109 ctx->block.sep_block_width = 9;
115 static int stdin_map_key(void *context, const unsigned char *key, size_t len) {
117 static int stdin_map_key(void *context, const unsigned char *key, unsigned int len) {
119 parser_ctx *ctx = context;
120 FREE(ctx->last_map_key);
121 sasprintf(&(ctx->last_map_key), "%.*s", len, key);
125 static int stdin_boolean(void *context, int val) {
126 parser_ctx *ctx = context;
127 if (strcasecmp(ctx->last_map_key, "urgent") == 0) {
128 ctx->block.urgent = val;
130 if (strcasecmp(ctx->last_map_key, "separator") == 0) {
131 ctx->block.no_separator = !val;
137 static int stdin_string(void *context, const unsigned char *val, size_t len) {
139 static int stdin_string(void *context, const unsigned char *val, unsigned int len) {
141 parser_ctx *ctx = context;
142 if (strcasecmp(ctx->last_map_key, "full_text") == 0) {
143 ctx->block.full_text = i3string_from_utf8_with_length((const char *)val, len);
145 if (strcasecmp(ctx->last_map_key, "color") == 0) {
146 sasprintf(&(ctx->block.color), "%.*s", len, val);
148 if (strcasecmp(ctx->last_map_key, "align") == 0) {
149 if (len == strlen("left") && !strncmp((const char*)val, "left", strlen("left"))) {
150 ctx->block.align = ALIGN_LEFT;
151 } else if (len == strlen("right") && !strncmp((const char*)val, "right", strlen("right"))) {
152 ctx->block.align = ALIGN_RIGHT;
154 ctx->block.align = ALIGN_CENTER;
156 } else if (strcasecmp(ctx->last_map_key, "min_width") == 0) {
157 i3String *text = i3string_from_utf8_with_length((const char *)val, len);
158 ctx->block.min_width = (uint32_t)predict_text_width(text);
161 if (strcasecmp(ctx->last_map_key, "name") == 0) {
162 char *copy = (char*)malloc(len+1);
163 strncpy(copy, (const char *)val, len);
165 ctx->block.name = copy;
167 if (strcasecmp(ctx->last_map_key, "instance") == 0) {
168 char *copy = (char*)malloc(len+1);
169 strncpy(copy, (const char *)val, len);
171 ctx->block.instance = copy;
177 static int stdin_integer(void *context, long long val) {
179 static int stdin_integer(void *context, long val) {
181 parser_ctx *ctx = context;
182 if (strcasecmp(ctx->last_map_key, "min_width") == 0) {
183 ctx->block.min_width = (uint32_t)val;
185 if (strcasecmp(ctx->last_map_key, "separator_block_width") == 0) {
186 ctx->block.sep_block_width = (uint32_t)val;
191 static int stdin_end_map(void *context) {
192 parser_ctx *ctx = context;
193 struct status_block *new_block = smalloc(sizeof(struct status_block));
194 memcpy(new_block, &(ctx->block), sizeof(struct status_block));
195 /* Ensure we have a full_text set, so that when it is missing (or null),
196 * i3bar doesn’t crash and the user gets an annoying message. */
197 if (!new_block->full_text)
198 new_block->full_text = i3string_from_utf8("SPEC VIOLATION (null)");
199 if (new_block->urgent)
200 ctx->has_urgent = true;
201 TAILQ_INSERT_TAIL(&statusline_head, new_block, blocks);
205 static int stdin_end_array(void *context) {
206 DLOG("dumping statusline:\n");
207 struct status_block *current;
208 TAILQ_FOREACH(current, &statusline_head, blocks) {
209 DLOG("full_text = %s\n", i3string_as_utf8(current->full_text));
210 DLOG("color = %s\n", current->color);
212 DLOG("end of dump\n");
217 * Helper function to read stdin
220 static unsigned char *get_buffer(ev_io *watcher, int *ret_buffer_len) {
221 int fd = watcher->fd;
224 int buffer_len = STDIN_CHUNK_SIZE;
225 unsigned char *buffer = smalloc(buffer_len+1);
228 n = read(fd, buffer + rec, buffer_len - rec);
230 if (errno == EAGAIN) {
234 ELOG("read() failed!: %s\n", strerror(errno));
238 /* end of file, kill the watcher */
239 ELOG("stdin: received EOF\n");
242 *ret_buffer_len = -1;
247 if (rec == buffer_len) {
248 buffer_len += STDIN_CHUNK_SIZE;
249 buffer = srealloc(buffer, buffer_len);
252 if (*buffer == '\0') {
256 *ret_buffer_len = rec;
260 static void read_flat_input(char *buffer, int length) {
261 struct status_block *first = TAILQ_FIRST(&statusline_head);
262 /* Clear the old buffer if any. */
263 I3STRING_FREE(first->full_text);
264 /* Remove the trailing newline and terminate the string at the same
266 if (buffer[length-1] == '\n' || buffer[length-1] == '\r')
267 buffer[length-1] = '\0';
268 else buffer[length] = '\0';
269 first->full_text = i3string_from_utf8(buffer);
272 static bool read_json_input(unsigned char *input, int length) {
273 yajl_status status = yajl_parse(parser, input, length);
274 bool has_urgent = false;
276 if (status != yajl_status_ok) {
278 if (status != yajl_status_ok && status != yajl_status_insufficient_data) {
280 fprintf(stderr, "[i3bar] Could not parse JSON input (code %d): %.*s\n",
281 status, length, input);
282 } else if (parser_context.has_urgent) {
289 * Callbalk for stdin. We read a line from stdin and store the result
293 void stdin_io_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
295 unsigned char *buffer = get_buffer(watcher, &rec);
298 bool has_urgent = false;
299 if (child.version > 0) {
300 has_urgent = read_json_input(buffer, rec);
302 read_flat_input((char*)buffer, rec);
305 draw_bars(has_urgent);
309 * Callbalk for stdin first line. We read the first line to detect
310 * whether this is JSON or plain text
313 void stdin_io_first_line_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
315 unsigned char *buffer = get_buffer(watcher, &rec);
318 DLOG("Detecting input type based on buffer *%.*s*\n", rec, buffer);
319 /* Detect whether this is JSON or plain text. */
320 unsigned int consumed = 0;
321 /* At the moment, we don’t care for the version. This might change
322 * in the future, but for now, we just discard it. */
323 parse_json_header(&child, buffer, rec, &consumed);
324 if (child.version > 0) {
325 /* If hide-on-modifier is set, we start of by sending the
326 * child a SIGSTOP, because the bars aren't mapped at start */
327 if (config.hide_on_modifier) {
330 read_json_input(buffer + consumed, rec - consumed);
332 /* In case of plaintext, we just add a single block and change its
333 * full_text pointer later. */
334 struct status_block *new_block = scalloc(sizeof(struct status_block));
335 TAILQ_INSERT_TAIL(&statusline_head, new_block, blocks);
336 read_flat_input((char*)buffer, rec);
339 ev_io_stop(main_loop, stdin_io);
340 ev_io_init(stdin_io, &stdin_io_cb, STDIN_FILENO, EV_READ);
341 ev_io_start(main_loop, stdin_io);
345 * We received a sigchild, meaning, that the child-process terminated.
346 * We simply free the respective data-structures and don't care for input
350 void child_sig_cb(struct ev_loop *loop, ev_child *watcher, int revents) {
351 ELOG("Child (pid: %d) unexpectedly exited with status %d\n",
357 void child_write_output(void) {
358 if (child.click_events) {
359 const unsigned char *output;
361 yajl_gen_get_buf(gen, &output, &size);
362 fwrite(output, 1, size, stdout);
363 fwrite("\n", 1, 1, stdout);
370 * Start a child-process with the specified command and reroute stdin.
371 * We actually start a $SHELL to execute the command so we don't have to care
372 * about arguments and such
375 void start_child(char *command) {
376 /* Allocate a yajl parser which will be used to parse stdin. */
377 memset(&callbacks, '\0', sizeof(yajl_callbacks));
378 callbacks.yajl_map_key = stdin_map_key;
379 callbacks.yajl_boolean = stdin_boolean;
380 callbacks.yajl_string = stdin_string;
381 callbacks.yajl_integer = stdin_integer;
382 callbacks.yajl_start_array = stdin_start_array;
383 callbacks.yajl_end_array = stdin_end_array;
384 callbacks.yajl_start_map = stdin_start_map;
385 callbacks.yajl_end_map = stdin_end_map;
387 yajl_parser_config parse_conf = { 0, 0 };
389 parser = yajl_alloc(&callbacks, &parse_conf, NULL, (void*)&parser_context);
391 parser = yajl_alloc(&callbacks, NULL, &parser_context);
394 gen = yajl_gen_alloc(NULL);
396 if (command != NULL) {
397 int pipe_in[2]; /* pipe we read from */
398 int pipe_out[2]; /* pipe we write to */
400 if (pipe(pipe_in) == -1)
401 err(EXIT_FAILURE, "pipe(pipe_in)");
402 if (pipe(pipe_out) == -1)
403 err(EXIT_FAILURE, "pipe(pipe_out)");
408 ELOG("Couldn't fork(): %s\n", strerror(errno));
411 /* Child-process. Reroute streams and start shell */
416 dup2(pipe_in[1], STDOUT_FILENO);
417 dup2(pipe_out[0], STDIN_FILENO);
419 static const char *shell = NULL;
421 if ((shell = getenv("SHELL")) == NULL)
424 execl(shell, shell, "-c", command, (char*) NULL);
427 /* Parent-process. Reroute streams */
432 dup2(pipe_in[0], STDIN_FILENO);
433 dup2(pipe_out[1], STDOUT_FILENO);
439 /* We set O_NONBLOCK because blocking is evil in event-driven software */
440 fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK);
442 stdin_io = smalloc(sizeof(ev_io));
443 ev_io_init(stdin_io, &stdin_io_first_line_cb, STDIN_FILENO, EV_READ);
444 ev_io_start(main_loop, stdin_io);
446 /* We must cleanup, if the child unexpectedly terminates */
447 child_sig = smalloc(sizeof(ev_child));
448 ev_child_init(child_sig, &child_sig_cb, child.pid, 0);
449 ev_child_start(main_loop, child_sig);
451 atexit(kill_child_at_exit);
454 void child_click_events_initialize(void) {
455 if (!child.click_events_init) {
456 yajl_gen_array_open(gen);
457 child_write_output();
458 child.click_events_init = true;
462 void child_click_events_key(const char *key) {
463 yajl_gen_string(gen, (const unsigned char *)key, strlen(key));
467 * Generates a click event, if enabled.
470 void send_block_clicked(int button, const char *name, const char *instance, int x, int y) {
471 if (child.click_events) {
472 child_click_events_initialize();
474 yajl_gen_map_open(gen);
477 child_click_events_key("name");
478 yajl_gen_string(gen, (const unsigned char *)name, strlen(name));
482 child_click_events_key("instance");
483 yajl_gen_string(gen, (const unsigned char *)instance, strlen(instance));
486 child_click_events_key("button");
487 yajl_gen_integer(gen, button);
489 child_click_events_key("x");
490 yajl_gen_integer(gen, x);
492 child_click_events_key("y");
493 yajl_gen_integer(gen, y);
495 yajl_gen_map_close(gen);
496 child_write_output();
501 * kill()s the child-process (if any). Called when exit()ing.
504 void kill_child_at_exit(void) {
506 if (child.cont_signal > 0 && child.stopped)
507 kill(child.pid, child.cont_signal);
508 kill(child.pid, SIGTERM);
513 * kill()s the child-process (if existent) and closes and
514 * free()s the stdin- and sigchild-watchers
517 void kill_child(void) {
519 if (child.cont_signal > 0 && child.stopped)
520 kill(child.pid, child.cont_signal);
521 kill(child.pid, SIGTERM);
523 waitpid(child.pid, &status, 0);
529 * Sends a SIGSTOP to the child-process (if existent)
532 void stop_child(void) {
533 if (child.stop_signal > 0 && !child.stopped) {
534 child.stopped = true;
535 kill(child.pid, child.stop_signal);
540 * Sends a SIGCONT to the child-process (if existent)
543 void cont_child(void) {
544 if (child.cont_signal > 0 && child.stopped) {
545 child.stopped = false;
546 kill(child.pid, child.cont_signal);