A simple stopwatch alias for bash
./sw.sh
Copy or link to your path
alias sw='echo "#### StopWatch #####";a=`date +%s`;while true; do b=`date +%s`;bn=`date +%3N`;date -d@"$(($b - $a))" -u +%H:%M:%S|tr -d "\n";echo -n ".$bn";sleep .1;echo -en "\r";done'
Add the alias to .bashrc