setled

#!/bin/bash -u           
# Script_name     : setled
# Author          : Bert Lindeman
# Description     : Set an EV3-led
# Version         : v1.3
# Date            : 2014-11-04
# Usage           : setled
# Notes           : 4 optional parameters:
#                   color [side [ON | OFF [valid MODE]]] 
# Copyright       : 2014 Bert Lindeman
# License         : GPL-3.0+
#
#============================================================================
#
# Changelog        
# Date     By       Description
# 20141104 BL       prepare for release v1.3
# 20140910 BL       Set ON to a higher value than 1 
#                   brightness since kernel 3.16.1 is honoured
#                   and no longer a switch                   
# 20140826 BL       add script header
# 20160103 BL       adapt to image 20151230 (change filenames)
#
#============================================================================

. /usr/local/bin/bert_ev3dev_functions

#
#  get parameters and translate to lowercase:
#
   # set default if parameter has not been specified: 
   if [ "$#" -lt 1 ]; then  : ${p1:=green}; else p1=$1; fi
   if [ "$#" -lt 2 ]; then  : ${p2:=left} ; else p2=$2; fi 
   if [ "$#" -lt 3 ]; then  : ${p3:=on}   ; else p3=$3; fi
   if [ "$#" -lt 4 ]; then  : ${p4:=none} ; else p4=$4; fi
   
    tosetColor="$(echo $p1 | tr 'A-Z' 'a-z')"
          side="$(echo $p2 | tr 'A-Z' 'a-z')"
          mode="$(echo $p3 | tr 'A-Z' 'a-z')"
  tosetTrigger="$(echo $p4 | tr 'A-Z' 'a-z')"

usageEXIT () {
     echo "$1"
     echo
     echo "USAGE: $0 color [side [\"ON\"|\"OFF\" [valid MODE]]]"
    exit 1
}

#set -v -x

#showLEDtrigger () {
# # echo "showing trigger from $1"
# for word in `cat $1` ;
#  do
#    delim=${word:0:1}${word:${#word}-1:1}
#    if [ $delim == "[]" ]; then
#      trigger=${word:1:${#word}-2}
#      # echo "current trigger now: $trigger"
#      break # do not search further
#    else
#      trigger=$word  
#    fi
#  done
#  currenttrigger=$trigger
#  echo "  current trigger=$currenttrigger" 
# }

verifyLEDtrigger () {
  for word in `cat $2` ;
  do
     delim=${word:0:1}${word:${#word}-1:1}
     if [ $delim == "[]" ]; then
       trigger=${word:1:${#word}-2}  # drop the first and last char: [ and ]
     else
       trigger=$word  
     fi
     if [ "$1" == "$trigger" ]; then
       : echo "  Trigger $1 is valid"
       return 0
     fi
  done
 
 # invalid trigger specified; show the valid ones:
  echo "specified trigger \"$1\" "
  for word in `cat $2` ;
  do
     delim=${word:0:1}${word:${#word}-1:1}
     if [ $delim == "[]" ]; then
       trigger=${word:1:${#word}-2}  # drop the first and last char: [ and ]
     else
       trigger=$word  
     fi
     echo "  acceptable trigger: \"$trigger\" "
  done
  usageEXIT "specified trigger \"$1\" is not recognized."
 
}

 # start of mainline:
 
 if [ "$#" -gt "4" ]; then
     usageEXIT "Too many parameters; Allowed 4 Got $#: $*"
 fi

 case $mode in
  on)
      command="echo";  valueORzero=127
     ;;
  off)
      command="echo";  valueORzero=0 
     ;;
  "")
      command="cat" # default
     ;;   
  *)
      usageEXIT "MODE should be on or off! Got \"$mode\""
     ;;
 esac

 case $tosetColor in
  red)
     ;;
  green)
     ;;
  "")
      color="green" # default
     ;;   
  *)
      usageEXIT "COLOR should be red or green! Got \"$tosetColor\""
     ;;
 esac

 case $side in
  left)
     ;;
  right)
     ;;
  *)
      usageEXIT "SIDE should be left or right! Got \"$side\""
     ;;
 esac

 ledbase="/sys/class/leds/ev3:$side:$tosetColor:ev3dev"
 ledbrightness="$ledbase/brightness"
 ledtriggerpath="$ledbase/trigger"
 
 if [ "$tosetTrigger" == "" ]; then
   tosetTrigger ="none"
 else  
   verifyLEDtrigger "$tosetTrigger" "$ledtriggerpath"
 fi
 
 echo "base directory $ledbase"
 
 if [ $command == "cat" ]; then
   echo "  brightness=`cat $ledbrightness`"
   showtrigger "`cat $ledtriggerpath`"
 else
   echo "BEFORE:"
   echo "  brightness=`cat $ledbrightness`"

   showtrigger "`cat $ledtriggerpath`"
   
   # echo "setting trigger to $tosetTrigger > $ledtriggerpath"
   if [ "$p4" != "" ]; then
     echo $tosetTrigger > $ledtriggerpath 
     if [ $? -ne 0 ]; then
       echo -e "!!!!!!!!returncode of trigger: $?"
     fi
   fi  
   # showLEDtrigger $ledtriggerpath  
   
   echo $valueORzero > $ledbrightness 
   if [ $? -ne 0 ]; then
     echo -e "!!!!!!!!returncode of command: $?"
   fi  
   echo "AFTER:"
   echo "  brightness=`cat $ledbrightness`"
   showtrigger "`cat $ledtriggerpath`"
 fi