View progress of long-running disk conversion tasks (en-/decryption) on macOS / OS X

disk-conversion-progress.sh

function displaytime {
  local T=$1
  local D=$((T/60/60/24))
  local H=$((T/60/60%24))
  local M=$((T/60%60))
  local S=$((T%60))
  (( $D > 0 )) && printf '%3s' $D && printf ' days '
  (( $H > 0 )) && printf '%2s' $H && printf ' hours '
  (( $M > 0 )) && printf '%2s' $M && printf ' minutes '
  if [ $D -lt 1 -a $H -lt 1 ]
  then
  	printf '%2s' $S && printf ' seconds'
  fi
}

function writeToLog {
  local date="$1"
  local progress="$2"
  local message="$3"
  local duration=$4
  local total=$5
  local average=$6
  
  printf "%19s" "$date"
  printf " | progress: "
  printf "%4s" "$progress%"
  
  if [ ! -z "$message" -a "$message" != " " ]
  then
  	printf " | "
  	printf "%-32s %s" "$message"
  fi
  
  if [ $output == "full" ]
  then
	if [ ! -z "$duration" -a "$duration" != " " ]
	then
	  printf " | duration: "
	  printf "%-25s%s" "$(displaytime $((duration)))"
	fi
	
	if [ ! -z "$total" -a "$total" != " " ]
	then
	  printf " | total: "
	  printf "%-25s%s" "$(displaytime $((total)))"
	fi
	
	if [ ! -z "$average" -a "$average" != " " ]
	then
	  	printf " | avg: "
	  	printf "%-25s%s" "$(displaytime $((average)))"
	fi
  fi
  
  if [ ! -z "$average" -a "$average" != " " ]
  then
  	printf " | approx: "
  	approxSecs=$((average * (100 - progress)))
  	printf "$(displaytime $approxSecs)"
  	printf " ( $(date -v "+"$approxSecs"S" +%Y-%m-%d\ %H:%M:%S) )"
  	
  fi
  
  printf "\n"
}

output="default"

if [ $# -eq 1 -a "$1" == "--full-output" ]
then
	output="full"
fi

currentPercent=0
totalDuration=0
averageDuration=0
index=0
status="searchStatus"

SECONDS=0

while
	[ $currentPercent -lt 100 ]
do
	
	percentIteration=0
	
	while
		diskutil cs list | grep -m 1 "Conversion Progress:   $currentPercent%" > /dev/null;
	do
		
		if [ $percentIteration -eq 0 ]
		then
			
			old_date=$(date +%Y-%m-%d\ %H:%M:%S)
			SECONDS=0
			
			if [ $status == "searchStatus" ]
			then
				writeToLog "$old_date" "$currentPercent" "waiting for the next full percent …"
				status="waitForEntry"
			fi
			
		fi
		
		percentIteration=$((percentIteration+1))
		
		sleep 15
	done
	
	currentPercent=$((currentPercent+1))
	
	duration=$SECONDS
	
	if [ $status == "searchStatus" ]
	then
	    continue
	elif [ $status == "waitForEntry" ]
	then
		writeToLog "$(date +%Y-%m-%d\ %H:%M:%S)" "$currentPercent" "start counting now …"
		status="counting"
		continue
	elif [ $status == "counting" ]
	then
		index=$((index+1))
		totalDuration=$((totalDuration+duration))
		averageDuration=$((totalDuration / index))
	
		writeToLog "$(date +%Y-%m-%d\ %H:%M:%S)" "$currentPercent" "" "$duration" "$totalDuration" "$averageDuration"
	fi

	
done

echo "finished!"

To make this work for APFS drives, replace the line

diskutil cs list | grep -m 1 "Conversion Progress:   $currentPercent%" > /dev/null;

with

diskutil apfs list | grep -m 1 "Encryption Progress:       $currentPercent.0%" > /dev/null