time_command.sh

#!/bin/sh


echo "Command: $1"
echo "Run count: $2"

CURRENT_TIME=$(date +%s)

I=0 # counter counts up to $2 - 1
TIME=0 # the whole time in ns

while [ "$I" != "$2" ]
do
    DATE1=$(date +%s%N)

    VAL=$($1)

    DATE2=$(date +%s%N)

    TIME="$(expr $(expr $DATE2 - $DATE1) + $TIME)"

    I=$(expr $I + 1)
done

echo "Time since start: $(expr $(date +%s) - $CURRENT_TIME) s"
echo "Time in command: $(expr $TIME / 1000000000).$(expr $TIME % 1000000000) s"
TIME_PER_RUN=$(expr $TIME / $2) # ns
echo "Time per run: $(expr $TIME_PER_RUN / 1000000).$(expr $TIME_PER_RUN % 1000000) ms"