git.sur5r.net Git - i3/i3status/blob - i3status.c

   1 /*
   2  * vim:ts=8:expandtab
   3  *
   4  * i3status – Generates a status line for dzen2 or xmobar
   5  *
   6  * Copyright © 2008-2012 Michael Stapelberg and contributors
   7  * Copyright © 2009 Thorsten Toepper <atsutane at freethoughts dot de>
   8  * Copyright © 2010 Axel Wagner <mail at merovius dot de>
   9  * Copyright © 2010 Fernando Tarlá Cardoso Lemos <fernandotcl at gmail dot com>
  10  *
  11  * See file LICENSE for license information.
  12  *
  13  */
  14 #include <string.h>
  15 #include <stdio.h>
  16 #include <stdbool.h>
  17 #include <unistd.h>
  18 #include <stdlib.h>
  19 #include <sys/socket.h>
  20 #include <netinet/in.h>
  21 #include <getopt.h>
  22 #include <signal.h>
  23 #include <confuse.h>
  24 #include <glob.h>
  25 #include <sys/stat.h>
  26 #include <sys/types.h>
  27 #include <time.h>
  28 #include <sys/time.h>
  29 #include <locale.h>
  30
  31 #include <yajl/yajl_gen.h>
  32 #include <yajl/yajl_version.h>
  33
  34 #include "i3status.h"
  35
  36 #define exit_if_null(pointer, ...) { if (pointer == NULL) die(__VA_ARGS__); }
  37
  38 #define CFG_COLOR_OPTS(good, degraded, bad) \
  39     CFG_STR("color_good", good, CFGF_NONE), \
  40     CFG_STR("color_degraded", degraded, CFGF_NONE), \
  41     CFG_STR("color_bad", bad, CFGF_NONE)
  42
  43 #define CFG_CUSTOM_COLOR_OPTS CFG_COLOR_OPTS(NULL, NULL, NULL)
  44
  45 /* socket file descriptor for general purposes */
  46 int general_socket;
  47
  48 static bool exit_upon_signal = false;
  49
  50 cfg_t *cfg, *cfg_general, *cfg_section;
  51
  52 /*
  53  * Set the exit_upon_signal flag, because one cannot do anything in a safe
  54  * manner in a signal handler (e.g. fprintf, which we really want to do for
  55  * debugging purposes), see
  56  * https://www.securecoding.cert.org/confluence/display/seccode/SIG30-C.+Call+only+asynchronous-safe+functions+within+signal+handlers
  57  *
  58  */
  59 void fatalsig(int signum) {
  60         exit_upon_signal = true;
  61 }
  62
  63 /*
  64  * Do nothing upon SIGUSR1. Running this signal handler will nevertheless
  65  * interrupt nanosleep() so that i3status immediately generates new output.
  66  *
  67  */
  68 void sigusr1(int signum) {
  69 }
  70
  71 /*
  72  * Checks if the given path exists by calling stat().
  73  *
  74  */
  75 static bool path_exists(const char *path) {
  76         struct stat buf;
  77         return (stat(path, &buf) == 0);
  78 }
  79
  80 static void *scalloc(size_t size) {
  81         void *result = calloc(size, 1);
  82         exit_if_null(result, "Error: out of memory (calloc(%zd))\n", size);
  83         return result;
  84 }
  85
  86 static char *sstrdup(const char *str) {
  87         char *result = strdup(str);
  88         exit_if_null(result, "Error: out of memory (strdup())\n");
  89         return result;
  90 }
  91
  92
  93 /*
  94  * Validates a color in "#RRGGBB" format
  95  *
  96  */
  97 static int valid_color(const char *value)
  98 {
  99         if (strlen(value) != 7) return 0;
 100         if (value[0] != '#') return 0;
 101         for (int i = 1; i < 7; ++i) {
 102                 if (value[i] >= '0' && value[i] <= '9') continue;
 103                 if (value[i] >= 'a' && value[i] <= 'f') continue;
 104                 if (value[i] >= 'A' && value[i] <= 'F') continue;
 105                 return 0;
 106         }
 107         return 1;
 108 }
 109
 110 /*
 111  * This function resolves ~ in pathnames.
 112  * It may resolve wildcards in the first part of the path, but if no match
 113  * or multiple matches are found, it just returns a copy of path as given.
 114  *
 115  */
 116 static char *resolve_tilde(const char *path) {
 117         static glob_t globbuf;
 118         char *head, *tail, *result = NULL;
 119
 120         tail = strchr(path, '/');
 121         head = strndup(path, tail ? (size_t)(tail - path) : strlen(path));
 122
 123         int res = glob(head, GLOB_TILDE, NULL, &globbuf);
 124         free(head);
 125         /* no match, or many wildcard matches are bad */
 126         if (res == GLOB_NOMATCH || globbuf.gl_pathc != 1)
 127                 result = sstrdup(path);
 128         else if (res != 0) {
 129                 die("glob() failed");
 130         } else {
 131                 head = globbuf.gl_pathv[0];
 132                 result = scalloc(strlen(head) + (tail ? strlen(tail) : 0) + 1);
 133                 strncpy(result, head, strlen(head));
 134                 if (tail)
 135                         strncat(result, tail, strlen(tail));
 136         }
 137         globfree(&globbuf);
 138
 139         return result;
 140 }
 141
 142 static char *get_config_path(void) {
 143         char *xdg_config_home, *xdg_config_dirs, *config_path;
 144
 145         /* 1: check the traditional path under the home directory */
 146         config_path = resolve_tilde("~/.i3status.conf");
 147         if (path_exists(config_path))
 148                 return config_path;
 149
 150         /* 2: check for $XDG_CONFIG_HOME/i3status/config */
 151         if ((xdg_config_home = getenv("XDG_CONFIG_HOME")) == NULL)
 152                 xdg_config_home = "~/.config";
 153
 154         xdg_config_home = resolve_tilde(xdg_config_home);
 155         if (asprintf(&config_path, "%s/i3status/config", xdg_config_home) == -1)
 156                 die("asprintf() failed");
 157         free(xdg_config_home);
 158
 159         if (path_exists(config_path))
 160                 return config_path;
 161         free(config_path);
 162
 163         /* 3: check the traditional path under /etc */
 164         config_path = SYSCONFDIR "/i3status.conf";
 165         if (path_exists(config_path))
 166             return sstrdup(config_path);
 167
 168         /* 4: check for $XDG_CONFIG_DIRS/i3status/config */
 169         if ((xdg_config_dirs = getenv("XDG_CONFIG_DIRS")) == NULL)
 170                 xdg_config_dirs = "/etc/xdg";
 171
 172         char *buf = strdup(xdg_config_dirs);
 173         char *tok = strtok(buf, ":");
 174         while (tok != NULL) {
 175                 tok = resolve_tilde(tok);
 176                 if (asprintf(&config_path, "%s/i3status/config", tok) == -1)
 177                         die("asprintf() failed");
 178                 free(tok);
 179                 if (path_exists(config_path)) {
 180                         free(buf);
 181                         return config_path;
 182                 }
 183                 free(config_path);
 184                 tok = strtok(NULL, ":");
 185         }
 186         free(buf);
 187
 188         die("Unable to find the configuration file (looked at "
 189                 "~/.i3status.conf, $XDG_CONFIG_HOME/i3status/config, "
 190                 "/etc/i3status.conf and $XDG_CONFIG_DIRS/i3status/config)");
 191         return NULL;
 192 }
 193
 194 int main(int argc, char *argv[]) {
 195         unsigned int j;
 196
 197         cfg_opt_t general_opts[] = {
 198                 CFG_STR("output_format", "auto", CFGF_NONE),
 199                 CFG_BOOL("colors", 1, CFGF_NONE),
 200                 CFG_STR("color_separator", "#333333", CFGF_NONE),
 201                 CFG_INT("interval", 1, CFGF_NONE),
 202                 CFG_COLOR_OPTS("#00FF00", "#FFFF00", "#FF0000"),
 203                 CFG_END()
 204         };
 205
 206         cfg_opt_t run_watch_opts[] = {
 207                 CFG_STR("pidfile", NULL, CFGF_NONE),
 208                 CFG_STR("format", "%title: %status", CFGF_NONE),
 209                 CFG_CUSTOM_COLOR_OPTS,
 210                 CFG_END()
 211         };
 212
 213         cfg_opt_t path_exists_opts[] = {
 214                 CFG_STR("path", NULL, CFGF_NONE),
 215                 CFG_STR("format", "%title: %status", CFGF_NONE),
 216                 CFG_CUSTOM_COLOR_OPTS,
 217                 CFG_END()
 218         };
 219
 220         cfg_opt_t wireless_opts[] = {
 221                 CFG_STR("format_up", "W: (%quality at %essid, %bitrate) %ip", CFGF_NONE),
 222                 CFG_STR("format_down", "W: down", CFGF_NONE),
 223                 CFG_CUSTOM_COLOR_OPTS,
 224                 CFG_END()
 225         };
 226
 227         cfg_opt_t ethernet_opts[] = {
 228                 CFG_STR("format_up", "E: %ip (%speed)", CFGF_NONE),
 229                 CFG_STR("format_down", "E: down", CFGF_NONE),
 230                 CFG_CUSTOM_COLOR_OPTS,
 231                 CFG_END()
 232         };
 233
 234         cfg_opt_t ipv6_opts[] = {
 235                 CFG_STR("format_up", "%ip", CFGF_NONE),
 236                 CFG_STR("format_down", "no IPv6", CFGF_NONE),
 237                 CFG_CUSTOM_COLOR_OPTS,
 238                 CFG_END()
 239         };
 240
 241         cfg_opt_t battery_opts[] = {
 242                 CFG_STR("format", "%status %percentage %remaining", CFGF_NONE),
 243                 CFG_STR("format_down", "No battery", CFGF_NONE),
 244                 CFG_STR("path", "/sys/class/power_supply/BAT%d/uevent", CFGF_NONE),
 245                 CFG_INT("low_threshold", 30, CFGF_NONE),
 246                 CFG_STR("threshold_type", "time", CFGF_NONE),
 247                 CFG_BOOL("last_full_capacity", false, CFGF_NONE),
 248                 CFG_BOOL("integer_battery_capacity", false, CFGF_NONE),
 249                 CFG_CUSTOM_COLOR_OPTS,
 250                 CFG_END()
 251         };
 252
 253         cfg_opt_t time_opts[] = {
 254                 CFG_STR("format", "%Y-%m-%d %H:%M:%S", CFGF_NONE),
 255                 CFG_END()
 256         };
 257
 258         cfg_opt_t tztime_opts[] = {
 259                 CFG_STR("format", "%Y-%m-%d %H:%M:%S %Z", CFGF_NONE),
 260                 CFG_STR("timezone", "", CFGF_NONE),
 261                 CFG_END()
 262         };
 263
 264         cfg_opt_t ddate_opts[] = {
 265                 CFG_STR("format", "%{%a, %b %d%}, %Y%N - %H", CFGF_NONE),
 266                 CFG_END()
 267         };
 268
 269         cfg_opt_t load_opts[] = {
 270                 CFG_STR("format", "%1min %5min %15min", CFGF_NONE),
 271                 CFG_FLOAT("max_threshold", 5, CFGF_NONE),
 272                 CFG_CUSTOM_COLOR_OPTS,
 273                 CFG_END()
 274         };
 275
 276         cfg_opt_t usage_opts[] = {
 277                 CFG_STR("format", "%usage", CFGF_NONE),
 278                 CFG_END()
 279         };
 280
 281         cfg_opt_t temp_opts[] = {
 282                 CFG_STR("format", "%degrees C", CFGF_NONE),
 283                 CFG_STR("path", NULL, CFGF_NONE),
 284                 CFG_INT("max_threshold", 75, CFGF_NONE),
 285                 CFG_CUSTOM_COLOR_OPTS,
 286                 CFG_END()
 287         };
 288
 289         cfg_opt_t disk_opts[] = {
 290                 CFG_STR("format", "%free", CFGF_NONE),
 291                 CFG_END()
 292         };
 293
 294         cfg_opt_t volume_opts[] = {
 295                 CFG_STR("format", "♪: %volume", CFGF_NONE),
 296                 CFG_STR("format_muted", "♪: 0%%", CFGF_NONE),
 297                 CFG_STR("device", "default", CFGF_NONE),
 298                 CFG_STR("mixer", "Master", CFGF_NONE),
 299                 CFG_INT("mixer_idx", 0, CFGF_NONE),
 300                 CFG_CUSTOM_COLOR_OPTS,
 301                 CFG_END()
 302         };
 303
 304         cfg_opt_t opts[] = {
 305                 CFG_STR_LIST("order", "{}", CFGF_NONE),
 306                 CFG_SEC("general", general_opts, CFGF_NONE),
 307                 CFG_SEC("run_watch", run_watch_opts, CFGF_TITLE | CFGF_MULTI),
 308                 CFG_SEC("path_exists", path_exists_opts, CFGF_TITLE | CFGF_MULTI),
 309                 CFG_SEC("wireless", wireless_opts, CFGF_TITLE | CFGF_MULTI),
 310                 CFG_SEC("ethernet", ethernet_opts, CFGF_TITLE | CFGF_MULTI),
 311                 CFG_SEC("battery", battery_opts, CFGF_TITLE | CFGF_MULTI),
 312                 CFG_SEC("cpu_temperature", temp_opts, CFGF_TITLE | CFGF_MULTI),
 313                 CFG_SEC("disk", disk_opts, CFGF_TITLE | CFGF_MULTI),
 314                 CFG_SEC("volume", volume_opts, CFGF_TITLE | CFGF_MULTI),
 315                 CFG_SEC("ipv6", ipv6_opts, CFGF_NONE),
 316                 CFG_SEC("time", time_opts, CFGF_NONE),
 317                 CFG_SEC("tztime", tztime_opts, CFGF_TITLE | CFGF_MULTI),
 318                 CFG_SEC("ddate", ddate_opts, CFGF_NONE),
 319                 CFG_SEC("load", load_opts, CFGF_NONE),
 320                 CFG_SEC("cpu_usage", usage_opts, CFGF_NONE),
 321                 CFG_CUSTOM_COLOR_OPTS,
 322                 CFG_END()
 323         };
 324
 325         char *configfile = NULL;
 326         int o, option_index = 0;
 327         struct option long_options[] = {
 328                 {"config", required_argument, 0, 'c'},
 329                 {"help", no_argument, 0, 'h'},
 330                 {"version", no_argument, 0, 'v'},
 331                 {0, 0, 0, 0}
 332         };
 333
 334         struct sigaction action;
 335         memset(&action, 0, sizeof(struct sigaction));
 336         action.sa_handler = fatalsig;
 337
 338         /* Exit upon SIGPIPE because when we have nowhere to write to, gathering system
 339          * information is pointless. Also exit explicitly on SIGTERM and SIGINT because
 340          * only this will trigger a reset of the cursor in the terminal output-format.
 341          */
 342         sigaction(SIGPIPE, &action, NULL);
 343         sigaction(SIGTERM, &action, NULL);
 344         sigaction(SIGINT, &action, NULL);
 345
 346         memset(&action, 0, sizeof(struct sigaction));
 347         action.sa_handler = sigusr1;
 348         sigaction(SIGUSR1, &action, NULL);
 349
 350         if (setlocale(LC_ALL, "") == NULL)
 351                 die("Could not set locale. Please make sure all your LC_* / LANG settings are correct.");
 352
 353         while ((o = getopt_long(argc, argv, "c:hv", long_options, &option_index)) != -1)
 354                 if ((char)o == 'c')
 355                         configfile = optarg;
 356                 else if ((char)o == 'h') {
 357                         printf("i3status " VERSION " © 2008-2012 Michael Stapelberg and contributors\n"
 358                                 "Syntax: %s [-c <configfile>] [-h] [-v]\n", argv[0]);
 359                         return 0;
 360                 } else if ((char)o == 'v') {
 361                         printf("i3status " VERSION " © 2008-2012 Michael Stapelberg and contributors\n");
 362                         return 0;
 363                 }
 364
 365
 366         if (configfile == NULL)
 367                 configfile = get_config_path();
 368
 369         cfg = cfg_init(opts, CFGF_NOCASE);
 370         if (cfg_parse(cfg, configfile) == CFG_PARSE_ERROR)
 371                 return EXIT_FAILURE;
 372
 373         if (cfg_size(cfg, "order") == 0)
 374                 die("Your 'order' array is empty. Please fix your config.\n");
 375
 376         cfg_general = cfg_getsec(cfg, "general");
 377         if (cfg_general == NULL)
 378                 die("Could not get section \"general\"\n");
 379
 380         char *output_str = cfg_getstr(cfg_general, "output_format");
 381         if (strcasecmp(output_str, "auto") == 0) {
 382                 fprintf(stderr, "i3status: trying to auto-detect output_format setting\n");
 383                 output_str = auto_detect_format();
 384                 if (!output_str) {
 385                         output_str = "none";
 386                         fprintf(stderr, "i3status: falling back to \"none\"\n");
 387                 } else {
 388                         fprintf(stderr, "i3status: auto-detected \"%s\"\n", output_str);
 389                 }
 390         }
 391
 392         if (strcasecmp(output_str, "dzen2") == 0)
 393                 output_format = O_DZEN2;
 394         else if (strcasecmp(output_str, "xmobar") == 0)
 395                 output_format = O_XMOBAR;
 396         else if (strcasecmp(output_str, "i3bar") == 0)
 397                 output_format = O_I3BAR;
 398         else if (strcasecmp(output_str, "term") == 0)
 399                 output_format = O_TERM;
 400         else if (strcasecmp(output_str, "none") == 0)
 401                 output_format = O_NONE;
 402         else die("Unknown output format: \"%s\"\n", output_str);
 403
 404         if (!valid_color(cfg_getstr(cfg_general, "color_good"))
 405                         || !valid_color(cfg_getstr(cfg_general, "color_degraded"))
 406                         || !valid_color(cfg_getstr(cfg_general, "color_bad"))
 407                         || !valid_color(cfg_getstr(cfg_general, "color_separator")))
 408                die("Bad color format");
 409
 410 #if YAJL_MAJOR >= 2
 411         yajl_gen json_gen = yajl_gen_alloc(NULL);
 412 #else
 413         yajl_gen json_gen = yajl_gen_alloc(NULL, NULL);
 414 #endif
 415
 416         if (output_format == O_I3BAR) {
 417                 /* Initialize the i3bar protocol. See i3/docs/i3bar-protocol
 418                  * for details. */
 419                 printf("{\"version\":1}\n[\n");
 420                 fflush(stdout);
 421                 yajl_gen_array_open(json_gen);
 422                 yajl_gen_clear(json_gen);
 423         }
 424         if (output_format == O_TERM) {
 425                 /* Save the cursor-position and hide the cursor */
 426                 printf("\033[s\033[?25l");
 427                 /* Undo at exit */
 428                 atexit(&reset_cursor);
 429         }
 430
 431         if ((general_socket = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
 432                 die("Could not create socket\n");
 433
 434         int interval = cfg_getint(cfg_general, "interval");
 435
 436         /* One memory page which each plugin can use to buffer output.
 437          * Even though it’s unclean, we just assume that the user will not
 438          * specify a format string which expands to something longer than 4096
 439          * bytes — given that the output of i3status is used to display
 440          * information on screen, more than 1024 characters for the full line
 441          * (!), not individual plugins, seem very unlikely. */
 442         char buffer[4096];
 443
 444         while (1) {
 445                 if (exit_upon_signal) {
 446                         fprintf(stderr, "Exiting due to signal.\n");
 447                         exit(1);
 448                 }
 449                 struct timeval tv;
 450                 gettimeofday(&tv, NULL);
 451                 if (output_format == O_I3BAR)
 452                         yajl_gen_array_open(json_gen);
 453                 else if (output_format == O_TERM)
 454                         /* Restore the cursor-position, clear line */
 455                         printf("\033[u\033[K");
 456                 for (j = 0; j < cfg_size(cfg, "order"); j++) {
 457                         if (j > 0)
 458                                 print_seperator();
 459
 460                         const char *current = cfg_getnstr(cfg, "order", j);
 461
 462                         CASE_SEC("ipv6") {
 463                                 SEC_OPEN_MAP("ipv6");
 464                                 print_ipv6_info(json_gen, buffer, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
 465                                 SEC_CLOSE_MAP;
 466                         }
 467
 468                         CASE_SEC_TITLE("wireless") {
 469                                 SEC_OPEN_MAP("wireless");
 470                                 print_wireless_info(json_gen, buffer, title, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
 471                                 SEC_CLOSE_MAP;
 472                         }
 473
 474                         CASE_SEC_TITLE("ethernet") {
 475                                 SEC_OPEN_MAP("ethernet");
 476                                 print_eth_info(json_gen, buffer, title, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
 477                                 SEC_CLOSE_MAP;
 478                         }
 479
 480                         CASE_SEC_TITLE("battery") {
 481                                 SEC_OPEN_MAP("battery");
 482                                 print_battery_info(json_gen, buffer, atoi(title), cfg_getstr(sec, "path"), cfg_getstr(sec, "format"), cfg_getstr(sec, "format_down"), cfg_getint(sec, "low_threshold"), cfg_getstr(sec, "threshold_type"), cfg_getbool(sec, "last_full_capacity"), cfg_getbool(sec, "integer_battery_capacity"));
 483                                 SEC_CLOSE_MAP;
 484                         }
 485
 486                         CASE_SEC_TITLE("run_watch") {
 487                                 SEC_OPEN_MAP("run_watch");
 488                                 print_run_watch(json_gen, buffer, title, cfg_getstr(sec, "pidfile"), cfg_getstr(sec, "format"));
 489                                 SEC_CLOSE_MAP;
 490                         }
 491
 492                         CASE_SEC_TITLE("path_exists") {
 493                                 SEC_OPEN_MAP("path_exists");
 494                                 print_path_exists(json_gen, buffer, title, cfg_getstr(sec, "path"), cfg_getstr(sec, "format"));
 495                                 SEC_CLOSE_MAP;
 496                         }
 497
 498                         CASE_SEC_TITLE("disk") {
 499                                 SEC_OPEN_MAP("disk_info");
 500                                 print_disk_info(json_gen, buffer, title, cfg_getstr(sec, "format"));
 501                                 SEC_CLOSE_MAP;
 502                         }
 503
 504                         CASE_SEC("load") {
 505                                 SEC_OPEN_MAP("load");
 506                                 print_load(json_gen, buffer, cfg_getstr(sec, "format"), cfg_getfloat(sec, "max_threshold"));
 507                                 SEC_CLOSE_MAP;
 508                         }
 509
 510                         CASE_SEC("time") {
 511                                 SEC_OPEN_MAP("time");
 512                                 print_time(json_gen, buffer, cfg_getstr(sec, "format"), NULL, tv.tv_sec);
 513                                 SEC_CLOSE_MAP;
 514                         }
 515
 516                         CASE_SEC_TITLE("tztime") {
 517                                 SEC_OPEN_MAP("tztime");
 518                                 print_time(json_gen, buffer, cfg_getstr(sec, "format"), cfg_getstr(sec, "timezone"), tv.tv_sec);
 519                                 SEC_CLOSE_MAP;
 520                         }
 521
 522                         CASE_SEC("ddate") {
 523                                 SEC_OPEN_MAP("ddate");
 524                                 print_ddate(json_gen, buffer, cfg_getstr(sec, "format"), tv.tv_sec);
 525                                 SEC_CLOSE_MAP;
 526                         }
 527
 528                         CASE_SEC_TITLE("volume") {
 529                                 SEC_OPEN_MAP("volume");
 530                                 print_volume(json_gen, buffer, cfg_getstr(sec, "format"),
 531                                              cfg_getstr(sec, "format_muted"),
 532                                              cfg_getstr(sec, "device"),
 533                                              cfg_getstr(sec, "mixer"),
 534                                              cfg_getint(sec, "mixer_idx"));
 535                                 SEC_CLOSE_MAP;
 536                         }
 537
 538                         CASE_SEC_TITLE("cpu_temperature") {
 539                                 SEC_OPEN_MAP("cpu_temperature");
 540                                 print_cpu_temperature_info(json_gen, buffer, atoi(title), cfg_getstr(sec, "path"), cfg_getstr(sec, "format"), cfg_getint(sec, "max_threshold"));
 541                                 SEC_CLOSE_MAP;
 542                         }
 543
 544                         CASE_SEC("cpu_usage") {
 545                                 SEC_OPEN_MAP("cpu_usage");
 546                                 print_cpu_usage(json_gen, buffer, cfg_getstr(sec, "format"));
 547                                 SEC_CLOSE_MAP;
 548                         }
 549                 }
 550                 if (output_format == O_I3BAR) {
 551                         yajl_gen_array_close(json_gen);
 552                         const unsigned char *buf;
 553 #if YAJL_MAJOR >= 2
 554                         size_t len;
 555 #else
 556                         unsigned int len;
 557 #endif
 558                         yajl_gen_get_buf(json_gen, &buf, &len);
 559                         write(STDOUT_FILENO, buf, len);
 560                         yajl_gen_clear(json_gen);
 561                 }
 562
 563                 printf("\n");
 564                 fflush(stdout);
 565
 566                 /* To provide updates on every full second (as good as possible)
 567                  * we don’t use sleep(interval) but we sleep until the next
 568                  * second (with microsecond precision) plus (interval-1)
 569                  * seconds. We also align to 60 seconds modulo interval such
 570                  * that we start with :00 on every new minute. */
 571                 struct timeval current_timeval;
 572                 gettimeofday(&current_timeval, NULL);
 573                 struct timespec ts = {interval - 1 - (current_timeval.tv_sec % interval), (10e5 - current_timeval.tv_usec) * 1000};
 574                 nanosleep(&ts, NULL);
 575         }
 576 }