• The printf command does NOT append a linefeed automatically unless you tell it to.
• Setting IFS to something else lets the shell split things apart into arrays on whatever delimiter you want, in this case , :.
• The date command can be used to produce time in seconds.
• Carriage returns return the cursor to the beginning of the line without moving to the next line.

function countdown
{
        local OLD_IFS="${IFS}"
        IFS=":"
        local ARR=( $1 )
        local SECONDS=$((  (ARR[0] * 60 * 60) + (ARR[1] * 60) + ARR[2]  ))
        local START=$(date +%s)
        local END=$((START + SECONDS))
        local CUR=$START

        while [[ $CUR -lt $END ]]
        do
                CUR=$(date +%s)
                LEFT=$((END-CUR))

                printf "\r%02d:%02d:%02d" \
                        $((LEFT/3600)) $(( (LEFT/60)%60)) $((LEFT%60))

                sleep 1
        done
        IFS="${OLD_IFS}"
        echo "        "
}

countdown "00:07:55"

Quote:

Originally Posted by Corona688 This uses a few tricks to do what you want:

countdown "00:07:55" Time left before entering the matrix

Quote:

Originally Posted by Corona688 Code: countdown "00:07:55"

That will fail for 00:08:09.

Here is my version, which will work in any POSIX shell:

Code:

countdown()
(
  IFS=:
  set -- $*
  secs=$(( ${1#0} * 3600 + ${2#0} * 60 + ${3#0} ))
  while [ $secs -gt 0 ]
  do
    sleep 1 &
    printf "\r%02d:%02d:%02d" $((secs/3600)) $(( (secs/60)%60)) $((secs%60))
    secs=$(( $secs - 1 ))
    wait
  done
  echo
)

sleep 1