battery.c

   1 /*-
   2  * "THE BEER-WARE LICENSE" (Revision 42):
   3  * <tobias.rehbein@web.de> wrote this file. As long as you retain this notice
   4  * you can do whatever you want with this stuff. If we meet some day, and you
   5  * think this stuff is worth it, you can buy me a beer in return.
   6  *                                                              Tobias Rehbein
   7  */
   8
   9 #define _POSIX_C_SOURCE 199506
  10
  11 #include <assert.h>
  12 #include <err.h>
  13 #include <fcntl.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17 #include <dev/acpica/acpiio.h>
  18 #include <sys/ioctl.h>
  19
  20 #include "battery.h"
  21 #include "buffers.h"
  22 #include "tools.h"
  23
  24 static const char *ACPIDEV = "/dev/acpi";
  25
  26 struct battery_context {
  27         int             fd;
  28         char            battery_str[BATTERY_BUFFLEN];
  29 };
  30
  31 struct battery_context *
  32 battery_context_open()
  33 {
  34         struct battery_context *ctx;
  35
  36         if ((ctx = malloc(sizeof(*ctx))) == NULL)
  37                 err(EXIT_FAILURE, "malloc(%d) battery_context", sizeof(*ctx));
  38         if ((ctx->fd = open(ACPIDEV, O_RDONLY)) == -1)
  39                 err(EXIT_FAILURE, "open(%s)", ACPIDEV);
  40
  41         return (ctx);
  42 }
  43
  44 void
  45 battery_context_close(struct battery_context *ctx)
  46 {
  47         assert(ctx != NULL);
  48
  49         if (close(ctx->fd) == -1)
  50                 err(EXIT_FAILURE, "close(%s)", ACPIDEV);
  51         free(ctx);
  52 }
  53
  54 char           *
  55 battery_str(struct battery_context *ctx)
  56 {
  57         union acpi_battery_ioctl_arg battio;
  58         const char     *state;
  59         char            cap[4];
  60
  61         assert(ctx != NULL);
  62
  63         battio.unit = ACPI_BATTERY_ALL_UNITS;
  64         if (ioctl(ctx->fd, ACPIIO_BATT_GET_BATTINFO, &battio) == -1)
  65                 err(EXIT_FAILURE, "ioctl(ACPIIO_BATT_GET_BATTINFO)");
  66
  67         if (battio.battinfo.state == 0)
  68                 state = "=";
  69         else if (battio.battinfo.state & ACPI_BATT_STAT_CRITICAL)
  70                 state = "!";
  71         else if (battio.battinfo.state & ACPI_BATT_STAT_DISCHARG)
  72                 state = "-";
  73         else if (battio.battinfo.state & ACPI_BATT_STAT_CHARGING)
  74                 state = "+";
  75         else
  76                 state = "?";
  77
  78         assert(battio.battinfo.cap >= 0 && battio.battinfo.cap <= 100 && sizeof(cap) > 3);
  79         sprintf(cap, "%d", battio.battinfo.cap);
  80
  81         tools_catitems(ctx->battery_str, sizeof(ctx->battery_str), cap, "% [", state, "]", NULL);
  82
  83         return (ctx->battery_str);
  84 }