text: /* See LICENSE file for copyright and license details. */
  
  /* interval between updates (in ms) */
  static const int interval = 10000;
  
  /* text to show if no value can be retrieved */
  static const char unknown_str[] = "n/a";
  
  /* maximum output string length */
  #define MAXLEN 2048
  
  /*
   * function             description                     argument
   *
   * battery_perc         battery percentage              battery name
   * battery_power        battery power usage             battery name
   * battery_state        battery charging state          battery name
   * cpu_perc             cpu usage in percent            NULL
   * cpu_iowait           cpu iowait in percent           NULL
   * cpu_freq             cpu frequency in MHz            NULL
   * datetime             date and time                   format string
   * disk_free            free disk space in GB           mountpoint path
   * disk_perc            disk usage in percent           mountpoint path
   * disk_total           total disk space in GB          mountpoint path
   * disk_used            used disk space in GB           mountpoint path
   * entropy              available entropy               NULL
   * gid                  GID of current user             NULL
   * hostname             hostname                        NULL
   * ipv4                 IPv4 address                    interface name
   * ipv6                 IPv6 address                    interface name
   * kernel_release       `uname -r`                      NULL
   * keyboard_indicators  caps/num lock indicators        NULL
   * load_avg             load average                    format string
   * num_files            number of files in a directory  path
   * ram_free             free memory in GB               NULL
   * ram_perc             memory usage in percent         NULL
   * ram_total            total memory size in GB         NULL
   * ram_used             used memory in GB               NULL
   * run_command          custom shell command            command
   * swap_free            free swap in GB                 NULL
   * swap_perc            swap usage in percent           NULL
   * swap_total           total swap size in GB           NULL
   * swap_used            used swap in GB                 NULL
   * temp                 temperature in degree celsius   sensor file
   * uid                  UID of current user             NULL
   * uptime               system uptime                   NULL
   * username             username of current user        NULL
   * vol_perc             OSS/ALSA volume in percent      "/dev/mixer"
   * wifi_perc            WiFi signal in percent          interface name
   * wifi_essid           WiFi ESSID                      interface name
   */
  static const struct arg args[] = {
  	/* function format          argument */
          { battery_perc, "B%3s%%", "BAT0" },
          { battery_state, "%s  ",     "BAT0"  },
  	{ cpu_perc, "C%3s%%  ", NULL    },
  	{ ram_perc, "M%3s%%  ", NULL    },
  	{ datetime, "%s ",       "%a %d %b %H:%M" },
  };
  