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 <sysexits.h>
  17 #include <unistd.h>
  18 #include <dev/acpica/acpiio.h>
  19 #include <sys/ioctl.h>
  20
  21 #include "battery.h"
  22 #include "buffers.h"
  23 #include "tools.h"
  24
  25 static const char *ACPIDEV = "/dev/acpi";
  26
  27 struct battery_context {
  28         int             fd;
  29         char            battery_str[BATTERY_BUFFLEN];
  30 };
  31
  32 struct battery_context *
  33 battery_context_open()
  34 {
  35         struct battery_context *ctx;
  36
  37         if ((ctx = malloc(sizeof(*ctx))) == NULL)
  38                 err(EX_SOFTWARE, "malloc(%d) battery_context", sizeof(*ctx));
  39         if ((ctx->fd = open(ACPIDEV, O_RDONLY)) == -1)
  40                 err(EX_OSFILE, "open(%s)", ACPIDEV);
  41
  42         return (ctx);
  43 }
  44
  45 void
  46 battery_context_close(struct battery_context *ctx)
  47 {
  48         assert(ctx != NULL);
  49
  50         if (close(ctx->fd) == -1)
  51                 err(EX_OSFILE, "close(%s)", ACPIDEV);
  52         free(ctx);
  53 }
  54
  55 char           *
  56 battery_str(struct battery_context *ctx)
  57 {
  58         union acpi_battery_ioctl_arg battio;
  59         const char     *state;
  60         char            cap[3 + 1];     /* capacity is a percentage so the
  61                                          * string representation will be at
  62                                          * most three character long */
  63
  64         assert(ctx != NULL);
  65
  66         battio.unit = ACPI_BATTERY_ALL_UNITS;
  67         if (ioctl(ctx->fd, ACPIIO_BATT_GET_BATTINFO, &battio) == -1)
  68                 err(EX_IOERR, "ioctl(ACPIIO_BATT_GET_BATTINFO)");
  69
  70         if (battio.battinfo.state == 0)
  71                 state = "=";
  72         else if (battio.battinfo.state & ACPI_BATT_STAT_CRITICAL)
  73                 state = "!";
  74         else if (battio.battinfo.state & ACPI_BATT_STAT_DISCHARG)
  75                 state = "-";
  76         else if (battio.battinfo.state & ACPI_BATT_STAT_CHARGING)
  77                 state = "+";
  78         else
  79                 state = "?";
  80
  81         sprintf(cap, "%d", battio.battinfo.cap);
  82         tools_catitems(ctx->battery_str, sizeof(ctx->battery_str), cap, "% [", state, "]", NULL);
  83
  84         return (ctx->battery_str);
  85 }