How to add a progress bar to a shell script?

Question

When scripting in bash or any other shell in *NIX, while running a command that will take more than a few seconds, a progress bar is needed.

For example, copying a b

Answer 1

I prefer to use dialog with the --gauge param. Is used very often in .deb package installations and other basic configuration stuff of many distros. So you don't need to reinvent the wheel... again

Just put an int value from 1 to 100 @stdin. One basic and silly example:

for a in {1..100}; do sleep .1s; echo $a| dialog --gauge "waiting" 7 30; done

I have this /bin/Wait file (with chmod u+x perms) for cooking purposes :P

#!/bin/bash
INIT=`/bin/date +%s`
NOW=$INIT
FUTURE=`/bin/date -d "$1" +%s`
[ $FUTURE -a $FUTURE -eq $FUTURE ] || exit
DIFF=`echo "$FUTURE - $INIT"|bc -l`

while [ $INIT -le $FUTURE -a $NOW -lt $FUTURE ]; do
    NOW=`/bin/date +%s`
    STEP=`echo "$NOW - $INIT"|bc -l`
    SLEFT=`echo "$FUTURE - $NOW"|bc -l`
    MLEFT=`echo "scale=2;$SLEFT/60"|bc -l`
    TEXT="$SLEFT seconds left ($MLEFT minutes)";
    TITLE="Waiting $1: $2"
    sleep 1s
    PTG=`echo "scale=0;$STEP * 100 / $DIFF"|bc -l`
    echo $PTG| dialog --title "$TITLE" --gauge "$TEXT" 7 72
done

if [ "$2" == "" ]; then msg="Espera terminada: $1";audio="Listo";
else msg=$2;audio=$2;fi 

/usr/bin/notify-send --icon=stock_appointment-reminder-excl "$msg"
espeak -v spanish "$audio"

So I can put:

Wait "34 min" "warm up the oven"

or

Wait "dec 31" "happy new year"