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light.sh (2142B)

      1 #!/bin/sh
      2 #
      3 # light
      4 
      5 ICON=''
      6 # intel_backlight for thinkpad at least
      7 LIGHT='/sys/class/backlight/intel_backlight'
      8 # 852 on thinkpad not sure if universal
      9 MAX_BRIGHTNESS="$([ -f "${LIGHT}/max_brightness" ] && cat "${LIGHT}/max_brightness")"
     10 
     11 get_brightness() {
     12     # first get brightness as percentile of max brightness
     13     brightness="$(cat "${LIGHT}/brightness")"
     14     # then convert to percentage in terms of one hundred
     15     brightness="$(printf '%s\n' "scale=10; (${brightness}/${MAX_BRIGHTNESS})*100" | bc)"
     16     # dont care bout decimal
     17     brightness="$(printf '%.0f\n' "${brightness}")"
     18 }
     19 
     20 set_brightness() {
     21     get_brightness
     22 
     23     if [ "${1}" = '+' ]; then
     24         # convert brightness percentage to actual brightness units then add percentage in actual brightness units
     25         if [ "${brightness}" -lt 100 ]; then brightness=$(printf '%s\n' "scale=10; ((${brightness}/100)*${MAX_BRIGHTNESS})+(${2}*(${MAX_BRIGHTNESS}/100))" | bc)
     26         else return
     27         fi
     28     elif [ "${1}" = '-' ]; then
     29         # same as above but substract
     30         if [ "${brightness}" -gt 0 ]; then brightness=$(printf '%s\n' "scale=10; ((${brightness}/100)*${MAX_BRIGHTNESS})-(${2}*(${MAX_BRIGHTNESS}/100))" | bc)
     31         else return
     32         fi
     33     fi
     34 
     35     # can the decimal
     36     brightness="$(printf '%.0f\n' ${brightness})"
     37 
     38     # keep between 0 and max brightness
     39     [ ${brightness} -lt 0 ] && brightness=0
     40     [ ${brightness} -gt ${MAX_BRIGHTNESS} ] && brightness=${MAX_BRIGHTNESS}
     41 
     42     # send brightness to file for future reading
     43     printf '%s\n' ${brightness} | doas tee "${LIGHT}/brightness" 1>/dev/null
     44 
     45     get_brightness
     46 
     47     env HERBE_ID=/0 herbe "Brightness: ${brightness}%" &
     48 }
     49 
     50 bar() {
     51     get_brightness
     52 
     53     printf '%s\n' "${ICON} ${brightness}%"
     54 }
     55 
     56 main() {
     57     # run only if backlight found
     58     [ -d "${LIGHT}" ] || return 1
     59 
     60     # called from bar
     61     [ ${#} -eq 0 ] && bar
     62 
     63     # bar usage
     64     case ${BLOCK_BUTTON} in
     65         4) set_brightness + 1 ;;
     66         5) set_brightness - 1 ;;
     67     esac
     68 
     69     # adjust brightness based on args
     70     # ${1} = +/- and ${2} = percentage
     71     [ "${*}" ] && set_brightness "${1}" "${2}"
     72 }
     73 
     74 main "${@}"