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I'm currently writing a Bash script. I want to download a file while printing text. For example, consider this script:

echo -e "---------------------------"
echo -e "Your file downloading..." 
echo -e "---------------------------"
wget example.com/1gbfile

In the second echo each . should be printed successively every second till the download finishes. If the number of . becomes three, like this: ..., it should be reset to only one . and continue the loop.

BeastOfCaerbannog
  • 16,703
Erikli
  • 429

1 Answers1

4
Main script:

Create the following script as the source for your progress/bouncing bar (I called it bash-progress):

#!/bin/bash

Initial configuration variables


Set time interval for progress delay (in fraction of seconds)


time_delay=".2"


Set left and right brackets (1 character)


lb="["


lb="("


lb=" "


rb="]"


rb=")"


rb=" "


Function to show bouncing bar while running command in the background


show_bouncer() {


If no argument is given, then this is run on the last command - else provide PID


if [[ -z $1 ]]
  then
    PID=$!
  else
    PID=$1
  fi
  ii=0


Define bouncer array (3 characters)


bo=('.  ' '.. ' '...' ' ..' '  .' ' ..' '...' '.. ')


bo=('⠄  ' '⠂⠄ ' '⠁⠂⠄' '⠂⠂⠂' '⠄⠂⠁' ' ⠄⠂' '  ⠄' '   ')


bo=('⡇  ' '⣿  ' '⣿⡇ ' '⢸⣿ ' ' ⣿⡇' ' ⢸⡇' '  ⡇' '   ')


True while the original command is running


while [[ -d "/proc/$PID" ]]
  do
    ch="${bo[(ii++)%${#bo[@]}]}"
    printf "%b" " ${lb}${ch}${rb}"
    sleep "$time_delay"
    # Adjust backspaces to bouncer length + 3
    printf "\b\b\b\b\b\b"
  done
}

The script can work in 2 ways: Either by using the PID of the last command run, or with a given PID. The most common use is with the last command.

Using it:

So you simply create your other script like this:

#!/bin/bash

Include Bash progress bars - or include the entire source in your script.


source "./bash-progress"


your_command_here &
show_bouncer

It's important to run the command in the background, since it then moves on immediately to show the bouncer.

You can easily test it with a sleep command:

#!/bin/bash

Include Bash progress bars - or include the entire source in your script.


source "./bash-progress"


sleep 5 &
show_bouncer
Bonus info:

To use with a PID other than the last one, you can use pgrep (-n for newest and -x for exact match) to find the latest instance of the process like this:

#!/bin/bash

Include Bash progress bars - or include the entire source in your script.


source "./bash-progress"


your_command &
do_something_else
do_anything_meanwhile
show_bouncer $(pgrep -nx "your_command")
Artur Meinild
  • 31,035