/*
* function description argument (example)
*
- * backlight_perc backlight percentage device name
- * (intel_backlight)
* battery_perc battery percentage battery name (BAT0)
* NULL on OpenBSD
* battery_state battery charging state battery name (BAT0)
* ipv6 IPv6 address interface name (eth0)
* kernel_release `uname -r` NULL
* keyboard_indicators caps/num lock indicators NULL
+ * keymap layout (variant) of current NULL
+ * keymap
* load_avg load average NULL
* netspeed_rx receive network speed interface name (wlan0)
* netspeed_tx transfer network speed interface name (wlan0)