The Linux Daily

Simple Stopwatch Script

The following is a short and plain shell script that will start a timer when you run the program that counts up. I think you could argue that it’s not a stopwatch because it doesn’t support laps, but it’s close enough for me. You can easy get started by copying the following code block into a text editor, saving as stopwatch.sh, running chmod +x stopwatch.sh to make it executable, and finally starting it with ./stopwatch.sh. To stop it, hit Ctrl+c.

#!/bin/bash

BEGIN=$(date +%s)

echo Starting Stopwatch...

while true; do
   NOW=$(date +%s)
   let DIFF=$(($NOW - $BEGIN))
   let MINS=$(($DIFF / 60))
   let SECS=$(($DIFF % 60))
   let HOURS=$(($DIFF / 3600))
   let DAYS=$(($DIFF / 86400))

   # \r  is a "carriage return" - returns cursor to start of line
   printf "\r%3d Days, %02d:%02d:%02d" $DAYS $HOURS $MINS $SECS
   sleep 0.25
done

The previous script will allow you to track from the time you say “go” until you stop it. It’s also nice to the real-estate on your terminal and will use backspace to remove the characters printed from before to make room for the new ones.

If you’re not worried about starting it “now” or real estate in the terminal, you could always use uptime and throw it into a while loop like this:

#!/bin/sh

while true; do uptime | cut -d' ' -f2; done

Both are simple, both have their own advantages and disadvantages. Choose wisely.

Source: unix.com forums

I used the scripts to help me figure out how long it was taking my desktop to lock up so I could troubleshoot it better. Another use might be to keep track of how much time you’re spending on the computer vs the amount of time spent skiing! Have fun either way.

Edit
A subscriber, Jim, came up with a much better stopwatch script than my thrown together example. Jim sent it via email, but I’ll post it here for all to see.

It doesn’t start counting till you press the spacebar, pressing the
spacebar again pauses it counting, until the spacebar is pressed to
continue counting.

Press ‘q’ to quit
Press ‘r’ to reset to zero

#!/bin/bash

# sets stdin to no echo and give a char every tenth of a sec.
stty -echo -icanon time 1 <&0

chkspace () {

  if ! read -t 0 ; then return 1 ; fi    # no char pressed
  read -n 1 ans
  if [ "$ans" = " " ]; then return 0 ; fi
  case "$ans" in
  r|R)  COUNT=0 ; BEGIN=$(date +%s)
        printf "\r%3d Days, %02d:%02d:%02d" 0 0 0 0
        ;;
  q|Q)  stty echo icanon <&0
        echo ""
        exit 0
        ;;
  [1-9]) echo " - $ans" ;;
  esac
  return 1
}

echo "Stopwatch: to start and stop press the SPACEBAR..."

printf "\r%3d Days, %02d:%02d:%02d" 0 0 0 0

COUNT=0
IFS=
while true ; do

  while true; do
    if chkspace ; then break; fi
    sleep 0.1
  done

  BEGIN=$(date +%s)
  while true; do
    NOW=$(date +%s)
    let DIFF=$(($NOW - $BEGIN + $COUNT))

    let MINS=$(($DIFF / 60))
    let SECS=$(($DIFF % 60))
    let HOURS=$(($DIFF / 3600))
    let DAYS=$(($DIFF / 86400))

    # \r  is a "carriage return" - returns cursor to start of line
    printf "\r%3d Days, %02d:%02d:%02d" $DAYS $HOURS $MINS $SECS

    if chkspace ; then break; fi
    sleep 0.1
  done

  COUNT=$DIFF
done