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;
63 * Stop and free() the stdin- and sigchild-watchers
67 if (stdin_io != NULL) {
68 ev_io_stop(main_loop, stdin_io);
70 FREE(statusline_buffer);
71 /* statusline pointed to memory within statusline_buffer */
75 if (child_sig != NULL) {
76 ev_child_stop(main_loop, child_sig);
80 memset(&child, 0, sizeof(i3bar_child));
84 * The start of a new array is the start of a new status line, so we clear all
88 static int stdin_start_array(void *context) {
89 struct status_block *first;
90 while (!TAILQ_EMPTY(&statusline_head)) {
91 first = TAILQ_FIRST(&statusline_head);
92 I3STRING_FREE(first->full_text);
95 FREE(first->instance);
96 TAILQ_REMOVE(&statusline_head, first, blocks);
103 * The start of a map is the start of a single block of the status line.
106 static int stdin_start_map(void *context) {
107 parser_ctx *ctx = context;
108 memset(&(ctx->block), '\0', sizeof(struct status_block));
110 /* Default width of the separator block. */
111 ctx->block.sep_block_width = 9;
117 static int stdin_map_key(void *context, const unsigned char *key, size_t len) {
119 static int stdin_map_key(void *context, const unsigned char *key, unsigned int len) {
121 parser_ctx *ctx = context;
122 FREE(ctx->last_map_key);
123 sasprintf(&(ctx->last_map_key), "%.*s", len, key);
127 static int stdin_boolean(void *context, int val) {
128 parser_ctx *ctx = context;
129 if (strcasecmp(ctx->last_map_key, "urgent") == 0) {
130 ctx->block.urgent = val;
132 if (strcasecmp(ctx->last_map_key, "separator") == 0) {
133 ctx->block.no_separator = !val;
139 static int stdin_string(void *context, const unsigned char *val, size_t len) {
141 static int stdin_string(void *context, const unsigned char *val, unsigned int len) {
143 parser_ctx *ctx = context;
144 if (strcasecmp(ctx->last_map_key, "full_text") == 0) {
145 ctx->block.full_text = i3string_from_utf8_with_length((const char *)val, len);
147 if (strcasecmp(ctx->last_map_key, "color") == 0) {
148 sasprintf(&(ctx->block.color), "%.*s", len, val);
150 if (strcasecmp(ctx->last_map_key, "align") == 0) {
151 if (len == strlen("left") && !strncmp((const char*)val, "left", strlen("left"))) {
152 ctx->block.align = ALIGN_LEFT;
153 } else if (len == strlen("right") && !strncmp((const char*)val, "right", strlen("right"))) {
154 ctx->block.align = ALIGN_RIGHT;
156 ctx->block.align = ALIGN_CENTER;
158 } else if (strcasecmp(ctx->last_map_key, "min_width") == 0) {
159 i3String *text = i3string_from_utf8_with_length((const char *)val, len);
160 ctx->block.min_width = (uint32_t)predict_text_width(text);
163 if (strcasecmp(ctx->last_map_key, "name") == 0) {
164 char *copy = (char*)malloc(len+1);
165 strncpy(copy, (const char *)val, len);
167 ctx->block.name = copy;
169 if (strcasecmp(ctx->last_map_key, "instance") == 0) {
170 char *copy = (char*)malloc(len+1);
171 strncpy(copy, (const char *)val, len);
173 ctx->block.instance = copy;
179 static int stdin_integer(void *context, long long val) {
181 static int stdin_integer(void *context, long val) {
183 parser_ctx *ctx = context;
184 if (strcasecmp(ctx->last_map_key, "min_width") == 0) {
185 ctx->block.min_width = (uint32_t)val;
187 if (strcasecmp(ctx->last_map_key, "separator_block_width") == 0) {
188 ctx->block.sep_block_width = (uint32_t)val;
193 static int stdin_end_map(void *context) {
194 parser_ctx *ctx = context;
195 struct status_block *new_block = smalloc(sizeof(struct status_block));
196 memcpy(new_block, &(ctx->block), sizeof(struct status_block));
197 /* Ensure we have a full_text set, so that when it is missing (or null),
198 * i3bar doesn’t crash and the user gets an annoying message. */
199 if (!new_block->full_text)
200 new_block->full_text = i3string_from_utf8("SPEC VIOLATION (null)");
201 if (new_block->urgent)
202 ctx->has_urgent = true;
203 TAILQ_INSERT_TAIL(&statusline_head, new_block, blocks);
207 static int stdin_end_array(void *context) {
208 DLOG("dumping statusline:\n");
209 struct status_block *current;
210 TAILQ_FOREACH(current, &statusline_head, blocks) {
211 DLOG("full_text = %s\n", i3string_as_utf8(current->full_text));
212 DLOG("color = %s\n", current->color);
214 DLOG("end of dump\n");
219 * Helper function to read stdin
222 static unsigned char *get_buffer(ev_io *watcher, int *ret_buffer_len) {
223 int fd = watcher->fd;
226 int buffer_len = STDIN_CHUNK_SIZE;
227 unsigned char *buffer = smalloc(buffer_len+1);
230 n = read(fd, buffer + rec, buffer_len - rec);
232 if (errno == EAGAIN) {
236 ELOG("read() failed!: %s\n", strerror(errno));
240 /* end of file, kill the watcher */
241 ELOG("stdin: received EOF\n");
244 *ret_buffer_len = -1;
249 if (rec == buffer_len) {
250 buffer_len += STDIN_CHUNK_SIZE;
251 buffer = srealloc(buffer, buffer_len);
254 if (*buffer == '\0') {
258 *ret_buffer_len = rec;
262 static void read_flat_input(char *buffer, int length) {
263 struct status_block *first = TAILQ_FIRST(&statusline_head);
264 /* Clear the old buffer if any. */
265 I3STRING_FREE(first->full_text);
266 /* Remove the trailing newline and terminate the string at the same
268 if (buffer[length-1] == '\n' || buffer[length-1] == '\r')
269 buffer[length-1] = '\0';
270 else buffer[length] = '\0';
271 first->full_text = i3string_from_utf8(buffer);
274 static bool read_json_input(unsigned char *input, int length) {
275 yajl_status status = yajl_parse(parser, input, length);
276 bool has_urgent = false;
278 if (status != yajl_status_ok) {
280 if (status != yajl_status_ok && status != yajl_status_insufficient_data) {
282 fprintf(stderr, "[i3bar] Could not parse JSON input (code %d): %.*s\n",
283 status, length, input);
284 } else if (parser_context.has_urgent) {
291 * Callbalk for stdin. We read a line from stdin and store the result
295 void stdin_io_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
297 unsigned char *buffer = get_buffer(watcher, &rec);
300 bool has_urgent = false;
301 if (child.version > 0) {
302 has_urgent = read_json_input(buffer, rec);
304 read_flat_input((char*)buffer, rec);
307 draw_bars(has_urgent);
311 * Callbalk for stdin first line. We read the first line to detect
312 * whether this is JSON or plain text
315 void stdin_io_first_line_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
317 unsigned char *buffer = get_buffer(watcher, &rec);
320 DLOG("Detecting input type based on buffer *%.*s*\n", rec, buffer);
321 /* Detect whether this is JSON or plain text. */
322 unsigned int consumed = 0;
323 /* At the moment, we don’t care for the version. This might change
324 * in the future, but for now, we just discard it. */
325 parse_json_header(&child, buffer, rec, &consumed);
326 if (child.version > 0) {
327 /* If hide-on-modifier is set, we start of by sending the
328 * child a SIGSTOP, because the bars aren't mapped at start */
329 if (config.hide_on_modifier) {
332 read_json_input(buffer + consumed, rec - consumed);
334 /* In case of plaintext, we just add a single block and change its
335 * full_text pointer later. */
336 struct status_block *new_block = scalloc(sizeof(struct status_block));
337 TAILQ_INSERT_TAIL(&statusline_head, new_block, blocks);
338 read_flat_input((char*)buffer, rec);
341 ev_io_stop(main_loop, stdin_io);
342 ev_io_init(stdin_io, &stdin_io_cb, STDIN_FILENO, EV_READ);
343 ev_io_start(main_loop, stdin_io);
347 * We received a sigchild, meaning, that the child-process terminated.
348 * We simply free the respective data-structures and don't care for input
352 void child_sig_cb(struct ev_loop *loop, ev_child *watcher, int revents) {
353 ELOG("Child (pid: %d) unexpectedly exited with status %d\n",
359 void child_write_output(void) {
360 if (child.click_events) {
361 const unsigned char *output;
367 yajl_gen_get_buf(gen, &output, &size);
368 write(child_stdin, output, size);
369 write(child_stdin, "\n", 1);
375 * Start a child-process with the specified command and reroute stdin.
376 * We actually start a $SHELL to execute the command so we don't have to care
377 * about arguments and such
380 void start_child(char *command) {
381 /* Allocate a yajl parser which will be used to parse stdin. */
382 memset(&callbacks, '\0', sizeof(yajl_callbacks));
383 callbacks.yajl_map_key = stdin_map_key;
384 callbacks.yajl_boolean = stdin_boolean;
385 callbacks.yajl_string = stdin_string;
386 callbacks.yajl_integer = stdin_integer;
387 callbacks.yajl_start_array = stdin_start_array;
388 callbacks.yajl_end_array = stdin_end_array;
389 callbacks.yajl_start_map = stdin_start_map;
390 callbacks.yajl_end_map = stdin_end_map;
392 yajl_parser_config parse_conf = { 0, 0 };
394 parser = yajl_alloc(&callbacks, &parse_conf, NULL, (void*)&parser_context);
396 gen = yajl_gen_alloc(NULL, NULL);
398 parser = yajl_alloc(&callbacks, NULL, &parser_context);
400 gen = yajl_gen_alloc(NULL);
403 if (command != NULL) {
404 int pipe_in[2]; /* pipe we read from */
405 int pipe_out[2]; /* pipe we write to */
407 if (pipe(pipe_in) == -1)
408 err(EXIT_FAILURE, "pipe(pipe_in)");
409 if (pipe(pipe_out) == -1)
410 err(EXIT_FAILURE, "pipe(pipe_out)");
415 ELOG("Couldn't fork(): %s\n", strerror(errno));
418 /* Child-process. Reroute streams and start shell */
423 dup2(pipe_in[1], STDOUT_FILENO);
424 dup2(pipe_out[0], STDIN_FILENO);
426 static const char *shell = NULL;
428 if ((shell = getenv("SHELL")) == NULL)
431 execl(shell, shell, "-c", command, (char*) NULL);
434 /* Parent-process. Reroute streams */
439 dup2(pipe_in[0], STDIN_FILENO);
440 child_stdin = pipe_out[1];
446 /* We set O_NONBLOCK because blocking is evil in event-driven software */
447 fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK);
449 stdin_io = smalloc(sizeof(ev_io));
450 ev_io_init(stdin_io, &stdin_io_first_line_cb, STDIN_FILENO, EV_READ);
451 ev_io_start(main_loop, stdin_io);
453 /* We must cleanup, if the child unexpectedly terminates */
454 child_sig = smalloc(sizeof(ev_child));
455 ev_child_init(child_sig, &child_sig_cb, child.pid, 0);
456 ev_child_start(main_loop, child_sig);
458 atexit(kill_child_at_exit);
461 void child_click_events_initialize(void) {
462 if (!child.click_events_init) {
463 yajl_gen_array_open(gen);
464 child_write_output();
465 child.click_events_init = true;
469 void child_click_events_key(const char *key) {
470 yajl_gen_string(gen, (const unsigned char *)key, strlen(key));
474 * Generates a click event, if enabled.
477 void send_block_clicked(int button, const char *name, const char *instance, int x, int y) {
478 if (child.click_events) {
479 child_click_events_initialize();
481 yajl_gen_map_open(gen);
484 child_click_events_key("name");
485 yajl_gen_string(gen, (const unsigned char *)name, strlen(name));
489 child_click_events_key("instance");
490 yajl_gen_string(gen, (const unsigned char *)instance, strlen(instance));
493 child_click_events_key("button");
494 yajl_gen_integer(gen, button);
496 child_click_events_key("x");
497 yajl_gen_integer(gen, x);
499 child_click_events_key("y");
500 yajl_gen_integer(gen, y);
502 yajl_gen_map_close(gen);
503 child_write_output();
508 * kill()s the child-process (if any). Called when exit()ing.
511 void kill_child_at_exit(void) {
513 if (child.cont_signal > 0 && child.stopped)
514 kill(child.pid, child.cont_signal);
515 kill(child.pid, SIGTERM);
520 * kill()s the child-process (if existent) and closes and
521 * free()s the stdin- and sigchild-watchers
524 void kill_child(void) {
526 if (child.cont_signal > 0 && child.stopped)
527 kill(child.pid, child.cont_signal);
528 kill(child.pid, SIGTERM);
530 waitpid(child.pid, &status, 0);
536 * Sends a SIGSTOP to the child-process (if existent)
539 void stop_child(void) {
540 if (child.stop_signal > 0 && !child.stopped) {
541 child.stopped = true;
542 kill(child.pid, child.stop_signal);
547 * Sends a SIGCONT to the child-process (if existent)
550 void cont_child(void) {
551 if (child.cont_signal > 0 && child.stopped) {
552 child.stopped = false;
553 kill(child.pid, child.cont_signal);