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

   1 // vim:ts=4:sw=4:expandtab
   2 #include <ctype.h>
   3 #include <time.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7 #include <yajl/yajl_gen.h>
   8 #include <yajl/yajl_version.h>
   9
  10 #include "i3status.h"
  11
  12 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
  13 #include <sys/types.h>
  14 #include <sys/sysctl.h>
  15 #include <dev/acpica/acpiio.h>
  16 #endif
  17
  18 #if defined(__OpenBSD__)
  19 #include <sys/types.h>
  20 #include <sys/ioctl.h>
  21 #include <sys/fcntl.h>
  22 #include <machine/apmvar.h>
  23 #endif
  24
  25 #if defined(__NetBSD__)
  26 #include <fcntl.h>
  27 #include <prop/proplib.h>
  28 #include <sys/envsys.h>
  29 #endif
  30
  31 /*
  32  * Get battery information from /sys. Note that it uses the design capacity to
  33  * calculate the percentage, not the last full capacity, so you can see how
  34  * worn off your battery is.
  35  *
  36  */
  37 void print_battery_info(yajl_gen json_gen, char *buffer, int number, const char *path, const char *format, const char *format_down, const char *status_chr, const char *status_bat, const char *status_full, int low_threshold, char *threshold_type, bool last_full_capacity, bool integer_battery_capacity, bool hide_seconds) {
  38     time_t empty_time;
  39     struct tm *empty_tm;
  40     char buf[1024];
  41     char statusbuf[16];
  42     char percentagebuf[16];
  43     char remainingbuf[256];
  44     char emptytimebuf[256];
  45     char consumptionbuf[256];
  46     const char *walk, *last;
  47     char *outwalk = buffer;
  48     bool watt_as_unit = false;
  49     bool colorful_output = false;
  50     int full_design = -1,
  51         remaining = -1,
  52         present_rate = -1,
  53         voltage = -1;
  54     charging_status_t status = CS_DISCHARGING;
  55
  56     memset(statusbuf, '\0', sizeof(statusbuf));
  57     memset(percentagebuf, '\0', sizeof(percentagebuf));
  58     memset(remainingbuf, '\0', sizeof(remainingbuf));
  59     memset(emptytimebuf, '\0', sizeof(emptytimebuf));
  60     memset(consumptionbuf, '\0', sizeof(consumptionbuf));
  61
  62     static char batpath[512];
  63     sprintf(batpath, path, number);
  64     INSTANCE(batpath);
  65
  66 #define BATT_STATUS_NAME(status) \
  67     (status == CS_CHARGING ? status_chr : (status == CS_DISCHARGING ? status_bat : status_full))
  68
  69 #if defined(LINUX)
  70     if (!slurp(batpath, buf, sizeof(buf))) {
  71         OUTPUT_FULL_TEXT(format_down);
  72         return;
  73     }
  74
  75     for (walk = buf, last = buf; (walk - buf) < 1024; walk++) {
  76         if (*walk == '\n') {
  77             last = walk + 1;
  78             continue;
  79         }
  80
  81         if (*walk != '=')
  82             continue;
  83
  84         if (BEGINS_WITH(last, "POWER_SUPPLY_ENERGY_NOW")) {
  85             watt_as_unit = true;
  86             remaining = atoi(walk + 1);
  87         } else if (BEGINS_WITH(last, "POWER_SUPPLY_CHARGE_NOW")) {
  88             watt_as_unit = false;
  89             remaining = atoi(walk + 1);
  90         } else if (BEGINS_WITH(last, "POWER_SUPPLY_CURRENT_NOW"))
  91             present_rate = abs(atoi(walk + 1));
  92         else if (BEGINS_WITH(last, "POWER_SUPPLY_VOLTAGE_NOW"))
  93             voltage = abs(atoi(walk + 1));
  94         /* on some systems POWER_SUPPLY_POWER_NOW does not exist, but actually
  95          * it is the same as POWER_SUPPLY_CURRENT_NOW but with μWh as
  96          * unit instead of μAh. We will calculate it as we need it
  97          * later. */
  98         else if (BEGINS_WITH(last, "POWER_SUPPLY_POWER_NOW"))
  99             present_rate = abs(atoi(walk + 1));
 100         else if (BEGINS_WITH(last, "POWER_SUPPLY_STATUS=Charging"))
 101             status = CS_CHARGING;
 102         else if (BEGINS_WITH(last, "POWER_SUPPLY_STATUS=Full"))
 103             status = CS_FULL;
 104         else {
 105             /* The only thing left is the full capacity */
 106             if (last_full_capacity) {
 107                 if (!BEGINS_WITH(last, "POWER_SUPPLY_ENERGY_FULL") &&
 108                     !BEGINS_WITH(last, "POWER_SUPPLY_CHARGE_FULL"))
 109                     continue;
 110             } else {
 111                 if (!BEGINS_WITH(last, "POWER_SUPPLY_CHARGE_FULL_DESIGN") &&
 112                     !BEGINS_WITH(last, "POWER_SUPPLY_ENERGY_FULL_DESIGN"))
 113                     continue;
 114             }
 115
 116             full_design = atoi(walk + 1);
 117         }
 118     }
 119
 120     /* the difference between POWER_SUPPLY_ENERGY_NOW and
 121      * POWER_SUPPLY_CHARGE_NOW is the unit of measurement. The energy is
 122      * given in mWh, the charge in mAh. So calculate every value given in
 123      * ampere to watt */
 124     if (!watt_as_unit) {
 125         present_rate = (((float)voltage / 1000.0) * ((float)present_rate / 1000.0));
 126
 127         if (voltage != -1) {
 128             remaining = (((float)voltage / 1000.0) * ((float)remaining / 1000.0));
 129             full_design = (((float)voltage / 1000.0) * ((float)full_design / 1000.0));
 130         }
 131     }
 132
 133     if ((full_design == -1) || (remaining == -1)) {
 134         OUTPUT_FULL_TEXT(format_down);
 135         return;
 136     }
 137
 138     (void)snprintf(statusbuf, sizeof(statusbuf), "%s", BATT_STATUS_NAME(status));
 139
 140     float percentage_remaining = (((float)remaining / (float)full_design) * 100);
 141     /* Some batteries report POWER_SUPPLY_CHARGE_NOW=<full_design> when fully
 142      * charged, even though that’s plainly wrong. For people who chose to see
 143      * the percentage calculated based on the last full capacity, we clamp the
 144      * value to 100%, as that makes more sense.
 145      * See http://bugs.debian.org/785398 */
 146     if (last_full_capacity && percentage_remaining > 100) {
 147         percentage_remaining = 100;
 148     }
 149     if (integer_battery_capacity) {
 150         (void)snprintf(percentagebuf, sizeof(percentagebuf), "%.00f%s", percentage_remaining, pct_mark);
 151     } else {
 152         (void)snprintf(percentagebuf, sizeof(percentagebuf), "%.02f%s", percentage_remaining, pct_mark);
 153     }
 154
 155     if (present_rate > 0) {
 156         float remaining_time;
 157         int seconds, hours, minutes, seconds_remaining;
 158         if (status == CS_CHARGING)
 159             remaining_time = ((float)full_design - (float)remaining) / (float)present_rate;
 160         else if (status == CS_DISCHARGING)
 161             remaining_time = ((float)remaining / (float)present_rate);
 162         else
 163             remaining_time = 0;
 164
 165         seconds_remaining = (int)(remaining_time * 3600.0);
 166
 167         hours = seconds_remaining / 3600;
 168         seconds = seconds_remaining - (hours * 3600);
 169         minutes = seconds / 60;
 170         seconds -= (minutes * 60);
 171
 172         if (status == CS_DISCHARGING && low_threshold > 0) {
 173             if (strcasecmp(threshold_type, "percentage") == 0 && percentage_remaining < low_threshold) {
 174                 START_COLOR("color_bad");
 175                 colorful_output = true;
 176             } else if (strcasecmp(threshold_type, "time") == 0 && seconds_remaining < 60 * low_threshold) {
 177                 START_COLOR("color_bad");
 178                 colorful_output = true;
 179             } else {
 180                 colorful_output = false;
 181             }
 182         }
 183
 184         if (hide_seconds)
 185             (void)snprintf(remainingbuf, sizeof(remainingbuf), "%02d:%02d",
 186                            max(hours, 0), max(minutes, 0));
 187         else
 188             (void)snprintf(remainingbuf, sizeof(remainingbuf), "%02d:%02d:%02d",
 189                            max(hours, 0), max(minutes, 0), max(seconds, 0));
 190
 191         empty_time = time(NULL);
 192         empty_time += seconds_remaining;
 193         empty_tm = localtime(&empty_time);
 194
 195         if (hide_seconds)
 196             (void)snprintf(emptytimebuf, sizeof(emptytimebuf), "%02d:%02d",
 197                            max(empty_tm->tm_hour, 0), max(empty_tm->tm_min, 0));
 198         else
 199             (void)snprintf(emptytimebuf, sizeof(emptytimebuf), "%02d:%02d:%02d",
 200                            max(empty_tm->tm_hour, 0), max(empty_tm->tm_min, 0), max(empty_tm->tm_sec, 0));
 201
 202         (void)snprintf(consumptionbuf, sizeof(consumptionbuf), "%1.2fW",
 203                        ((float)present_rate / 1000.0 / 1000.0));
 204     } else {
 205         /* On some systems, present_rate may not exist. Still, make sure
 206          * we colorize the output if threshold_type is set to percentage
 207          * (since we don't have any information on remaining time). */
 208         if (status == CS_DISCHARGING && low_threshold > 0) {
 209             if (strcasecmp(threshold_type, "percentage") == 0 && percentage_remaining < low_threshold) {
 210                 START_COLOR("color_bad");
 211                 colorful_output = true;
 212             }
 213         }
 214     }
 215 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 216     int state;
 217     int sysctl_rslt;
 218     size_t sysctl_size = sizeof(sysctl_rslt);
 219
 220     if (sysctlbyname(BATT_LIFE, &sysctl_rslt, &sysctl_size, NULL, 0) != 0) {
 221         OUTPUT_FULL_TEXT(format_down);
 222         return;
 223     }
 224
 225     present_rate = sysctl_rslt;
 226     if (sysctlbyname(BATT_TIME, &sysctl_rslt, &sysctl_size, NULL, 0) != 0) {
 227         OUTPUT_FULL_TEXT(format_down);
 228         return;
 229     }
 230
 231     remaining = sysctl_rslt;
 232     if (sysctlbyname(BATT_STATE, &sysctl_rslt, &sysctl_size, NULL, 0) != 0) {
 233         OUTPUT_FULL_TEXT(format_down);
 234         return;
 235     }
 236
 237     state = sysctl_rslt;
 238     if (state == 0 && present_rate == 100)
 239         status = CS_FULL;
 240     else if ((state & ACPI_BATT_STAT_CHARGING) && present_rate < 100)
 241         status = CS_CHARGING;
 242     else
 243         status = CS_DISCHARGING;
 244
 245     full_design = sysctl_rslt;
 246
 247     (void)snprintf(statusbuf, sizeof(statusbuf), "%s", BATT_STATUS_NAME(status));
 248
 249     (void)snprintf(percentagebuf, sizeof(percentagebuf), "%02d%s",
 250                    present_rate, pct_mark);
 251
 252     if (state == ACPI_BATT_STAT_DISCHARG) {
 253         int hours, minutes;
 254         minutes = remaining;
 255         hours = minutes / 60;
 256         minutes -= (hours * 60);
 257         (void)snprintf(remainingbuf, sizeof(remainingbuf), "%02d:%02d",
 258                        max(hours, 0), max(minutes, 0));
 259         if (strcasecmp(threshold_type, "percentage") == 0 && present_rate < low_threshold) {
 260             START_COLOR("color_bad");
 261             colorful_output = true;
 262         } else if (strcasecmp(threshold_type, "time") == 0 && remaining < (u_int)low_threshold) {
 263             START_COLOR("color_bad");
 264             colorful_output = true;
 265         }
 266     }
 267 #elif defined(__OpenBSD__)
 268     /*
 269          * We're using apm(4) here, which is the interface to acpi(4) on amd64/i386 and
 270          * the generic interface on macppc/sparc64/zaurus, instead of using sysctl(3) and
 271          * probing acpi(4) devices.
 272          */
 273     struct apm_power_info apm_info;
 274     int apm_fd;
 275
 276     apm_fd = open("/dev/apm", O_RDONLY);
 277     if (apm_fd < 0) {
 278         OUTPUT_FULL_TEXT("can't open /dev/apm");
 279         return;
 280     }
 281     if (ioctl(apm_fd, APM_IOC_GETPOWER, &apm_info) < 0)
 282         OUTPUT_FULL_TEXT("can't read power info");
 283
 284     close(apm_fd);
 285
 286     /* Don't bother to go further if there's no battery present. */
 287     if ((apm_info.battery_state == APM_BATTERY_ABSENT) ||
 288         (apm_info.battery_state == APM_BATT_UNKNOWN)) {
 289         OUTPUT_FULL_TEXT(format_down);
 290         return;
 291     }
 292
 293     switch (apm_info.ac_state) {
 294         case APM_AC_OFF:
 295             status = CS_DISCHARGING;
 296             break;
 297         case APM_AC_ON:
 298             status = CS_CHARGING;
 299             break;
 300         default:
 301             /* If we don't know what's going on, just assume we're discharging. */
 302             status = CS_DISCHARGING;
 303             break;
 304     }
 305
 306     (void)snprintf(statusbuf, sizeof(statusbuf), "%s", BATT_STATUS_NAME(status));
 307     /* integer_battery_capacity is implied as battery_life is already in whole numbers. */
 308     (void)snprintf(percentagebuf, sizeof(percentagebuf), "%.00d%s", apm_info.battery_life, pct_mark);
 309
 310     if (status == CS_DISCHARGING && low_threshold > 0) {
 311         if (strcasecmp(threshold_type, "percentage") == 0 && apm_info.battery_life < low_threshold) {
 312             START_COLOR("color_bad");
 313             colorful_output = true;
 314         } else if (strcasecmp(threshold_type, "time") == 0 && apm_info.minutes_left < (u_int)low_threshold) {
 315             START_COLOR("color_bad");
 316             colorful_output = true;
 317         }
 318     }
 319
 320     /* Can't give a meaningful value for remaining minutes if we're charging. */
 321     if (status != CS_CHARGING) {
 322         (void)snprintf(remainingbuf, sizeof(remainingbuf), "%02d:%02d", apm_info.minutes_left / 60, apm_info.minutes_left % 60);
 323     } else {
 324         (void)snprintf(remainingbuf, sizeof(remainingbuf), "%s", "(CHR)");
 325     }
 326
 327     if (colorful_output)
 328         END_COLOR;
 329 #elif defined(__NetBSD__)
 330     /*
 331      * Using envsys(4) via sysmon(4).
 332      */
 333     int fd, rval, last_full_cap;
 334     bool is_found = false;
 335     char *sensor_desc;
 336     bool is_full = false;
 337
 338     prop_dictionary_t dict;
 339     prop_array_t array;
 340     prop_object_iterator_t iter;
 341     prop_object_iterator_t iter2;
 342     prop_object_t obj, obj2, obj3, obj4, obj5;
 343
 344     asprintf(&sensor_desc, "acpibat%d", number);
 345
 346     fd = open("/dev/sysmon", O_RDONLY);
 347     if (fd < 0) {
 348         OUTPUT_FULL_TEXT("can't open /dev/sysmon");
 349         return;
 350     }
 351
 352     rval = prop_dictionary_recv_ioctl(fd, ENVSYS_GETDICTIONARY, &dict);
 353     if (rval == -1) {
 354         close(fd);
 355         return;
 356     }
 357
 358     if (prop_dictionary_count(dict) == 0) {
 359         prop_object_release(dict);
 360         close(fd);
 361         return;
 362     }
 363
 364     iter = prop_dictionary_iterator(dict);
 365     if (iter == NULL) {
 366         prop_object_release(dict);
 367         close(fd);
 368     }
 369
 370     /* iterate over the dictionary returned by the kernel */
 371     while ((obj = prop_object_iterator_next(iter)) != NULL) {
 372         /* skip this dict if it's not what we're looking for */
 373         if ((strlen(prop_dictionary_keysym_cstring_nocopy(obj)) == strlen(sensor_desc)) &&
 374             (strncmp(sensor_desc,
 375                      prop_dictionary_keysym_cstring_nocopy(obj),
 376                      strlen(sensor_desc)) != 0))
 377             continue;
 378
 379         is_found = true;
 380
 381         array = prop_dictionary_get_keysym(dict, obj);
 382         if (prop_object_type(array) != PROP_TYPE_ARRAY) {
 383             prop_object_iterator_release(iter);
 384             prop_object_release(dict);
 385             close(fd);
 386             return;
 387         }
 388
 389         iter2 = prop_array_iterator(array);
 390         if (!iter2) {
 391             prop_object_iterator_release(iter);
 392             prop_object_release(dict);
 393             close(fd);
 394             return;
 395         }
 396
 397         /* iterate over array of dicts specific to target battery */
 398         while ((obj2 = prop_object_iterator_next(iter2)) != NULL) {
 399             obj3 = prop_dictionary_get(obj2, "description");
 400
 401             if (obj3 &&
 402                 strlen(prop_string_cstring_nocopy(obj3)) == 8 &&
 403                 strncmp("charging",
 404                         prop_string_cstring_nocopy(obj3),
 405                         8) == 0) {
 406                 obj3 = prop_dictionary_get(obj2, "cur-value");
 407
 408                 if (prop_number_integer_value(obj3))
 409                     status = CS_CHARGING;
 410                 else
 411                     status = CS_DISCHARGING;
 412
 413                 continue;
 414             }
 415
 416             if (obj3 &&
 417                 strlen(prop_string_cstring_nocopy(obj3)) == 6 &&
 418                 strncmp("charge",
 419                         prop_string_cstring_nocopy(obj3),
 420                         6) == 0) {
 421                 obj3 = prop_dictionary_get(obj2, "cur-value");
 422                 obj4 = prop_dictionary_get(obj2, "max-value");
 423                 obj5 = prop_dictionary_get(obj2, "type");
 424
 425                 remaining = prop_number_integer_value(obj3);
 426                 full_design = prop_number_integer_value(obj4);
 427
 428                 if (remaining == full_design)
 429                     is_full = true;
 430
 431                 if (strncmp("Ampere hour",
 432                             prop_string_cstring_nocopy(obj5),
 433                             11) == 0)
 434                     watt_as_unit = false;
 435                 else
 436                     watt_as_unit = true;
 437
 438                 continue;
 439             }
 440
 441             if (obj3 &&
 442                 strlen(prop_string_cstring_nocopy(obj3)) == 14 &&
 443                 strncmp("discharge rate",
 444                         prop_string_cstring_nocopy(obj3),
 445                         14) == 0) {
 446                 obj3 = prop_dictionary_get(obj2, "cur-value");
 447                 present_rate = prop_number_integer_value(obj3);
 448                 continue;
 449             }
 450
 451             if (obj3 &&
 452                 strlen(prop_string_cstring_nocopy(obj3)) == 13 &&
 453                 strncmp("last full cap",
 454                         prop_string_cstring_nocopy(obj3),
 455                         13) == 0) {
 456                 obj3 = prop_dictionary_get(obj2, "cur-value");
 457                 last_full_cap = prop_number_integer_value(obj3);
 458                 continue;
 459             }
 460
 461             if (obj3 &&
 462                 strlen(prop_string_cstring_nocopy(obj3)) == 7 &&
 463                 strncmp("voltage",
 464                         prop_string_cstring_nocopy(obj3),
 465                         7) == 0) {
 466                 obj3 = prop_dictionary_get(obj2, "cur-value");
 467                 voltage = prop_number_integer_value(obj3);
 468                 continue;
 469             }
 470         }
 471         prop_object_iterator_release(iter2);
 472     }
 473
 474     prop_object_iterator_release(iter);
 475     prop_object_release(dict);
 476     close(fd);
 477
 478     if (!is_found) {
 479         OUTPUT_FULL_TEXT(format_down);
 480         return;
 481     }
 482
 483     if (last_full_capacity)
 484         full_design = last_full_cap;
 485
 486     if (!watt_as_unit) {
 487         present_rate = (((float)voltage / 1000.0) * ((float)present_rate / 1000.0));
 488         remaining = (((float)voltage / 1000.0) * ((float)remaining / 1000.0));
 489         full_design = (((float)voltage / 1000.0) * ((float)full_design / 1000.0));
 490     }
 491
 492     float percentage_remaining =
 493         (((float)remaining / (float)full_design) * 100);
 494
 495     if (integer_battery_capacity)
 496         (void)snprintf(percentagebuf,
 497                        sizeof(percentagebuf),
 498                        "%d%s",
 499                        (int)percentage_remaining, pct_mark);
 500     else
 501         (void)snprintf(percentagebuf,
 502                        sizeof(percentagebuf),
 503                        "%.02f%s",
 504                        percentage_remaining, pct_mark);
 505
 506     /*
 507      * Handle percentage low_threshold here, and time low_threshold when
 508      * we have it.
 509      */
 510     if (status == CS_DISCHARGING && low_threshold > 0) {
 511         if (strcasecmp(threshold_type, "percentage") == 0 && (((float)remaining / (float)full_design) * 100) < low_threshold) {
 512             START_COLOR("color_bad");
 513             colorful_output = true;
 514         }
 515     }
 516
 517     if (is_full)
 518         (void)snprintf(statusbuf, sizeof(statusbuf), "%s", BATT_STATUS_NAME(CS_FULL));
 519     else
 520         (void)snprintf(statusbuf, sizeof(statusbuf), "%s", BATT_STATUS_NAME(status));
 521
 522     /*
 523      * The envsys(4) ACPI routines do not appear to provide a 'time
 524      * remaining' figure, so we must deduce it.
 525      */
 526     float remaining_time;
 527     int seconds, hours, minutes, seconds_remaining;
 528
 529     if (status == CS_CHARGING)
 530         remaining_time = ((float)full_design - (float)remaining) / (float)present_rate;
 531     else if (status == CS_DISCHARGING)
 532         remaining_time = ((float)remaining / (float)present_rate);
 533     else
 534         remaining_time = 0;
 535
 536     seconds_remaining = (int)(remaining_time * 3600.0);
 537
 538     hours = seconds_remaining / 3600;
 539     seconds = seconds_remaining - (hours * 3600);
 540     minutes = seconds / 60;
 541     seconds -= (minutes * 60);
 542
 543     if (status != CS_CHARGING) {
 544         if (hide_seconds)
 545             (void)snprintf(remainingbuf, sizeof(remainingbuf), "%02d:%02d",
 546                            max(hours, 0), max(minutes, 0));
 547         else
 548             (void)snprintf(remainingbuf, sizeof(remainingbuf), "%02d:%02d:%02d",
 549                            max(hours, 0), max(minutes, 0), max(seconds, 0));
 550
 551         if (low_threshold > 0) {
 552             if (strcasecmp(threshold_type, "time") == 0 && ((float)seconds_remaining / 60.0) < (u_int)low_threshold) {
 553                 START_COLOR("color_bad");
 554                 colorful_output = true;
 555             }
 556         }
 557     } else {
 558         if (hide_seconds)
 559             (void)snprintf(remainingbuf, sizeof(remainingbuf), "(%02d:%02d until full)",
 560                            max(hours, 0), max(minutes, 0));
 561         else
 562             (void)snprintf(remainingbuf, sizeof(remainingbuf), "(%02d:%02d:%02d until full)",
 563                            max(hours, 0), max(minutes, 0), max(seconds, 0));
 564     }
 565
 566     empty_time = time(NULL);
 567     empty_time += seconds_remaining;
 568     empty_tm = localtime(&empty_time);
 569
 570     /* No need to show empty time if battery is charging */
 571     if (status != CS_CHARGING) {
 572         if (hide_seconds)
 573             (void)snprintf(emptytimebuf, sizeof(emptytimebuf), "%02d:%02d",
 574                            max(empty_tm->tm_hour, 0), max(empty_tm->tm_min, 0));
 575         else
 576             (void)snprintf(emptytimebuf, sizeof(emptytimebuf), "%02d:%02d:%02d",
 577                            max(empty_tm->tm_hour, 0), max(empty_tm->tm_min, 0), max(empty_tm->tm_sec, 0));
 578     }
 579
 580     (void)snprintf(consumptionbuf, sizeof(consumptionbuf), "%1.2fW",
 581                    ((float)present_rate / 1000.0 / 1000.0));
 582 #endif
 583
 584 #define EAT_SPACE_FROM_OUTPUT_IF_EMPTY(_buf)              \
 585     do {                                                  \
 586         if (strlen(_buf) == 0) {                          \
 587             if (outwalk > buffer && isspace(outwalk[-1])) \
 588                 outwalk--;                                \
 589             else if (isspace(*(walk + 1)))                \
 590                 walk++;                                   \
 591         }                                                 \
 592     } while (0)
 593
 594     for (walk = format; *walk != '\0'; walk++) {
 595         if (*walk != '%') {
 596             *(outwalk++) = *walk;
 597             continue;
 598         }
 599
 600         if (BEGINS_WITH(walk + 1, "status")) {
 601             outwalk += sprintf(outwalk, "%s", statusbuf);
 602             walk += strlen("status");
 603         } else if (BEGINS_WITH(walk + 1, "percentage")) {
 604             outwalk += sprintf(outwalk, "%s", percentagebuf);
 605             walk += strlen("percentage");
 606         } else if (BEGINS_WITH(walk + 1, "remaining")) {
 607             outwalk += sprintf(outwalk, "%s", remainingbuf);
 608             walk += strlen("remaining");
 609             EAT_SPACE_FROM_OUTPUT_IF_EMPTY(remainingbuf);
 610         } else if (BEGINS_WITH(walk + 1, "emptytime")) {
 611             outwalk += sprintf(outwalk, "%s", emptytimebuf);
 612             walk += strlen("emptytime");
 613             EAT_SPACE_FROM_OUTPUT_IF_EMPTY(emptytimebuf);
 614         } else if (BEGINS_WITH(walk + 1, "consumption")) {
 615             outwalk += sprintf(outwalk, "%s", consumptionbuf);
 616             walk += strlen("consumption");
 617             EAT_SPACE_FROM_OUTPUT_IF_EMPTY(consumptionbuf);
 618         }
 619     }
 620
 621     if (colorful_output)
 622         END_COLOR;
 623
 624     OUTPUT_FULL_TEXT(buffer);
 625 }