battery.c

   1 #include <limits.h>
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 #include "util.h"
   6
   7 const char *
   8 battery_perc(const char *bat)
   9 {
  10         int perc;
  11         char path[PATH_MAX];
  12
  13         snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/capacity");
  14         return (pscanf(path, "%i", &perc) == 1) ?
  15                bprintf("%d", perc) : NULL;
  16 }
  17
  18 const char *
  19 battery_power(const char *bat)
  20 {
  21         int watts;
  22         char path[PATH_MAX];
  23
  24         snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/power_now");
  25         return (pscanf(path, "%i", &watts) == 1) ?
  26                bprintf("%d", (watts + 500000) / 1000000) : NULL;
  27 }
  28
  29 const char *
  30 battery_state(const char *bat)
  31 {
  32         struct {
  33                 char *state;
  34                 char *symbol;
  35         } map[] = {
  36                 { "Charging",    "+" },
  37                 { "Discharging", "-" },
  38                 { "Full",        "=" },
  39                 { "Unknown",     "/" },
  40         };
  41         size_t i;
  42         char path[PATH_MAX], state[12];
  43
  44         snprintf(path, sizeof(path), "%s%s%s", "/sys/class/power_supply/", bat, "/status");
  45         if (pscanf(path, "%12s", state) != 1) {
  46                 return NULL;
  47         }
  48
  49         for (i = 0; i < LEN(map); i++) {
  50                 if (!strcmp(map[i].state, state)) {
  51                         break;
  52                 }
  53         }
  54         return (i == LEN(map)) ? "?" : map[i].symbol;
  55 }