You may also be interested in how to do a spinner:

Can I do a spinner in Bash?

Sure!

i=1
sp="/-\|"
echo -n ' '
while true
do
    printf "\b${sp:i++%${#sp}:1}"
done

Each time the loop iterates, it displays the next character in the sp string, wrapping around as it reaches the end. (i is the position of the current character to display and ${#sp} is the length of the sp string).

The \b string is replaced by a 'backspace' character. Alternatively, you could play with \r to go back to the beginning of the line.

If you want it to slow down, put a sleep command inside the loop (after the printf).

A POSIX equivalent would be:

sp='/-\|'
printf ' '
while true; do
    printf '\b%.1s' "$sp"
    sp=${sp#?}${sp%???}
done

If you already have a loop which does a lot of work, you can call the following function at the beginning of each iteration to update the spinner:

sp="/-\|"
sc=0
spin() {
   printf "\b${sp:sc++:1}"
   ((sc==${#sp})) && sc=0
}
endspin() {
   printf "\r%s\n" "$@"
}

until work_done; do
   spin
   some_work ...
done
endspin

Got an easy progress bar function that i wrote the other day:

#!/bin/bash
# 1. Create ProgressBar function
# 1.1 Input is currentState($1) and totalState($2)
function ProgressBar {
# Process data
    let _progress=(${1}*100/${2}*100)/100
    let _done=(${_progress}*4)/10
    let _left=40-$_done
# Build progressbar string lengths
    _fill=$(printf "%${_done}s")
    _empty=$(printf "%${_left}s")

# 1.2 Build progressbar strings and print the ProgressBar line
# 1.2.1 Output example:                           
# 1.2.1.1 Progress : [########################################] 100%
printf "\rProgress : [${_fill// /#}${_empty// /-}] ${_progress}%%"

}

# Variables
_start=1

# This accounts as the "totalState" variable for the ProgressBar function
_end=100

# Proof of concept
for number in $(seq ${_start} ${_end})
do
    sleep 0.1
    ProgressBar ${number} ${_end}
done
printf '\nFinished!\n'

Or snag it from,
https://github.com/fearside/ProgressBar/

Use the Linux command pv.

It doesn't know the size if it's in the middle of the pipeline, but it gives a speed and total, and from there you can figure out how long it should take and get feedback so you know it hasn't hung.

Hires (floating point) progress bar

Yet Another Bash Progress Bar...

Preamble

Sorry for this not so short answer. In this answer I will address

• granularity and look, by using integer to render floating point, UTF-8 fonts for rendering progress bar more finely,
• interaction between your program and the bar rendering jobs, by using parallelism
• some samples, running another task (sha1sum) in order to follow his progression, with minimal resource footprint using pure bash and no forks.
• creating separated background task to show a spinner while your main script continue, with the two function: startSpinner and stopSpinner.

For impatiens: Please test code (copy/paste in a new terminal window) at Now do it! (in the middle), with

• either: Last animated demo,
• either any of Practical samples.

All demos here use read -t <float seconds> && break instead of sleep. So all loop could be nicely stopped by hitting Return key.

1. Avoid forks!

Because a progress bar are intented to run while other process are working, this must be a nice process...

So avoid using forks when not needed. Sample: instead of

mysmiley=$(printf '%b' \\U1F60E)

Use

printf -v mysmiley '%b' \\U1F60E

Explanation: When you run var=$(command), you initiate a new process to execute command and send his output to variable $var once terminated. This is very resource expensive. Please compare:

TIMEFORMAT="%R"
time for ((i=2500;i--;)){ mysmiley=$(printf '%b' \\U1F60E);}
2.292
time for ((i=2500;i--;)){ printf -v mysmiley '%b' \\U1F60E;}
0.017
bc -l <<<'2.292/.017'
134.82352941176470588235

On my host, same work of assigning $mysmiley (just 2500 time), seem ~135x slower / more expensive by using fork than by using built-in printf -v.

Then

echo $mysmiley 
😎

So your function have to not print (or output) anything. Your function have to attribute his answer to a variable.

2. Use integer as pseudo floating point

Here is a very small and quick function to compute percents from integers, with integer and answer a pseudo floating point number:

percent(){
    local p=00$(($1*100000/$2))
    printf -v "$3" %.2f ${p::-3}.${p: -3}
}

Usage:

# percent <integer to compare> <reference integer> <variable name>
percent 33333 50000 testvar
printf '%8s%%\n' "$testvar"
   66.67%

3. Hires console graphic using UTF-8: ▏ ▎ ▍ ▌ ▋ ▊ ▉ █

To render this characters using bash, you could:

printf -v chars '\\U258%X ' {15..8}
printf '%b\n' "$chars"
▏ ▎ ▍ ▌ ▋ ▊ ▉ █ 

or

printf %b\  \\U258{{f..a},9,8}
▏ ▎ ▍ ▌ ▋ ▊ ▉ █

Then we have to use 8x string width as graphic width.

Now do it!

This function is named percentBar because it render a bar from argument submited in percents (floating):

percentBar ()  { 
    local prct totlen=$((8*$2)) lastchar barstring blankstring;
    printf -v prct %.2f "$1"
    ((prct=10#${prct/.}*totlen/10000, prct%8)) &&
        printf -v lastchar '\\U258%X' $(( 16 - prct%8 )) ||
            lastchar=''
    printf -v barstring '%*s' $((prct/8)) ''
    printf -v barstring '%b' "${barstring// /\\U2588}$lastchar"
    printf -v blankstring '%*s' $(((totlen-prct)/8)) ''
    printf -v "$3" '%s%s' "$barstring" "$blankstring"
}

Usage:

# percentBar <float percent> <int string width> <variable name>
percentBar 42.42 $COLUMNS bar1
echo "$bar1"
█████████████████████████████████▉                                              

To show little differences:

percentBar 42.24 $COLUMNS bar2
printf "%s\n" "$bar1" "$bar2"
█████████████████████████████████▉                                              
█████████████████████████████████▊                                              

With colors

As rendered variable is a fixed widht string, using color is easy:

percentBar 72.1 24 bar
printf 'Show this: \e[44;33;1m%s\e[0m at %s%%\n' "$bar" 72.1

Little animation:

for i in {0..10000..33} 10000;do i=0$i
    printf -v p %0.2f ${i::-2}.${i: -2}
    percentBar $p $((COLUMNS-9)) bar
    printf '\r|%s|%6.2f%%' "$bar" $p
    read -srt .002 _ && break    # console sleep avoiding fork
done

|███████████████████████████████████████████████████████████████████████|100.00%

clear; for i in {0..10000..33} 10000;do i=0$i
     printf -v p %0.2f ${i::-2}.${i: -2}
     percentBar $p $((COLUMNS-7)) bar
     printf '\r\e[47;30m%s\e[0m%6.2f%%' "$bar" $p
     read -srt .002 _ && break
done

Last animated demo

Another demo showing different sizes and colored output:

printf '\n\n\n\n\n\n\n\n\e[8A\e7'&&for i in {0..9999..99} 10000;do 
    o=1 i=0$i;printf -v p %0.2f ${i::-2}.${i: -2}
    for l in 1 2 3 5 8 13 20 40 $((COLUMNS-7));do
        percentBar $p $l bar$((o++));done
    [ "$p" = "100.00" ] && read -rst .8 _;printf \\e8
    printf '%s\e[48;5;23;38;5;41m%s\e[0m%6.2f%%%b' 'In 1 char width: ' \
        "$bar1" $p ,\\n 'with 2 chars: ' "$bar2" $p ,\\n 'or 3 chars: ' \
        "$bar3" $p ,\\n 'in 5 characters: ' "$bar4" $p ,\\n 'in 8 chars: ' \
        "$bar5" $p .\\n 'There are 13 chars: ' "$bar6" $p ,\\n '20 chars: '\
        "$bar7" $p ,\\n 'then 40 chars' "$bar8" $p \
        ', or full width:\n' '' "$bar9" $p ''
    ((10#$i)) || read -st .5 _; read -st .1 _ && break
done

Could produce something like this:

Practical GNU/Linux sample 1: kind of sleep with progress bar

Rewrite feb 2023: Turn into more usefull displaySleep function suitable to use as displayed timeout read:

This sleep show a progress bar with 50 refresh by seconds (tunnable)

percent(){ local p=00$(($1*100000/$2));printf -v "$3" %.2f ${p::-3}.${p: -3};}
displaySleep() {
    local -i refrBySeconds=50
    local -i _start=${EPOCHREALTIME/.} reqslp target crtslp crtp cols cpos dlen
    local strng percent prctbar tleft
    [[ $COLUMNS ]] && cols=${COLUMNS} || read -r cols < <(tput cols)
    refrBySeconds=' 1000000 / refrBySeconds '
    printf -v strng %.6f $1
    printf '\E[6n' && IFS=\; read -sdR _ cpos
    dlen=${#strng}-1  cols=' cols - dlen - cpos -1 '
    printf \\e7
    reqslp=10#${strng/.} target=reqslp+_start
    for ((;${EPOCHREALTIME/.}<target;)){
        crtp=${EPOCHREALTIME/.}
        crtslp='( target - crtp ) > refrBySeconds? refrBySeconds: target - crtp'
        strng=00000$crtslp  crtp+=-_start
        printf -v strng %.6f ${strng::-6}.${strng: -6}
        percent $crtp $reqslp percent
        percentBar $percent $cols prctbar
        tleft=00000$((reqslp-crtp))
        printf '\e8\e[36;48;5;23m%s\e[0m%*.4fs' \
               "$prctbar" "$dlen" ${tleft::-6}.${tleft: -6}
        IFS= read -rsn1 -t $strng ${2:-_} && { echo; return;}
    }
    percentBar 100 $cols prctbar
    printf '\e8\e[36;48;5;30m%s\e[0m%*.4fs\n' "$prctbar" "$dlen" 0
    false
}

This will keep current cursor position to fill only the rest of line (full line if current cursor position is 1).

This could be useful for displaying some kind of read timeout: Display some prompt by running:

TIMEFORMAT=%R
time displaySleep 1.5
time displaySleep 1.5 userKey && echo ${userKey@Q} || echo Done
printf 'Hit any key in \e[1m3 secs\e[0m to stop ("A" for "accept"): ';\
    time displaySleep 3 userKey && echo User hit ${userKey@Q}. || echo Done.

Should show something like:

Practical GNU/Linux sample 2: sha1sum with progress bar

Under linux, you could find a lot of usefull infos under /proc pseudo filesystem, so using previoulsy defined functions percentBar and percent, here is sha1progress:

percent(){ local p=00$(($1*100000/$2));printf -v "$3" %.2f ${p::-3}.${p: -3};}
sha1Progress() { 
    local -i totsize crtpos cols=$(tput cols) sha1in sha1pid
    local sha1res percent prctbar
    exec {sha1in}< <(exec sha1sum -b - <"$1")
    sha1pid=$!
    read -r totsize < <(stat -Lc %s "$1")
    while ! read -ru $sha1in -t .025 sha1res _; do
        read -r _ crtpos < /proc/$sha1pid/fdinfo/0
        percent $crtpos $totsize percent
        percentBar $percent $((cols-8)) prctbar
        printf '\r\e[44;38;5;25m%s\e[0m%6.2f%%' "$prctbar" $percent;

    done
    printf "\r%s  %s\e[K\n" $sha1res "$1"
}

Of course, 25 ms timeout mean approx 40 refresh per second. This could look overkill, but work fine on my host, and anyway, this can be tunned.

Explanation:

• exec {sha1in}< create a new file descriptor for the output of
• <( ... ) forked task run in background
• sha1sum -b - <"$1" ensuring input came from STDIN (fd/0)
• while ! read -ru $sha1in -t .025 sha1res _ While no input read from subtask, in 25 ms...
• /proc/$sha1pid/fdinfo/0 kernel variable showing information about file descriptor 0 (STDIN) of task $sha1pid

Variants using width x2 instead of x8

Inspired by [python]'s pip._internal.cli.progress_bars, noticed that UTF-8 do offer a lot of different characters filling HALF or FULL character width:

• HEAVY HORIZONTAL: '╺ ━ ╸'
• LIGHT HORIZONTAL: '╶ ─ ╴'
• LOWER HALF/QUADRANT: '▗ ▄ ▖'
• UPPER HALF/QUADRANT: '▝ ▀ ▘'
• BRAILLE PATTERN: '⠰ ⠶ ⠆'

and lot more...

I've built this variant:

percentBar2 () {
    local prct totlen=$(( 2 * $2 )) lastchar lhs rhs \
          lmr=${4:-'\U257a\U2501\U2578'} sep="${5:-\\e[1m:\\e[0;2m}"
    printf -v lmr %b "$lmr"
    printf -v prct %.2f "$1"
    ((prct=10#${prct/.}*totlen/10000, prct%2)) && lastchar="${lmr:2}"
    printf -v lhs '%*s' $((prct/2)) '';
    printf -v rhs '%*s' $(((totlen-prct-1)/2)) '';
    [[ -z $lastchar ]] && (( totlen > prct )) && rhs="${lmr::1}$rhs";
    printf -v "$3" '%b%b%b%b%b\e[0m' "${sep%:*}" "${lhs// /${lmr:1:1}}" \
            "$lastchar" "${sep#*:}" "${rhs// /${lmr:1:1}}"
}

I've called them percentBar2 because of x2 instead of x8. So less precision on small width, but permit nice designs!

Chars: ''
Width 1 char ▕╺▏, 3 chars ▕╸━━▏, 12 chars ▕━━━╺━━━━━━━━▏, or full width:  28.93%
━━━━━━━━━━━━━━━━━━━━━━━╺━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Chars: '▗ ▄ ▖'
Width 1 char ▕▗▏, 3 chars ▕▖▄▄▏, 12 chars ▕▄▄▄▗▄▄▄▄▄▄▄▄▏, or full width:  28.93%
▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▗▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄
Chars: '╺ ━ ╸'
Width 1 char ▕╺▏, 3 chars ▕╸━━▏, 12 chars ▕━━━╺━━━━━━━━▏, or full width:  28.93%
━━━━━━━━━━━━━━━━━━━━━━━╺━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Chars: '╶ ─ ╴'
Width 1 char ▕╶▏, 3 chars ▕╴──▏, 12 chars ▕───╶────────▏, or full width:  28.93%
───────────────────────╶────────────────────────────────────────────────────────
Chars: '▝ ▀ ▘'
Width 1 char ▕▝▏, 3 chars ▕▘▀▀▏, 12 chars ▕▀▀▀▝▀▀▀▀▀▀▀▀▏, or full width:  28.93%
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▝▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
Chars: '⠰ ⠶ ⠆'
Width 1 char ▕⠰▏, 3 chars ▕⠆⠶⠶▏, 12 chars ▕⠶⠶⠶⠰⠶⠶⠶⠶⠶⠶⠶⠶▏, or full width:  28.93%
⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠰⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶⠶

Full demo, showing both percentBar and percentBar2:

#!/bin/bash
# shellcheck disable=SC2059   
COLUMNS=$(tput cols) bar=()

doDelay() {
    local delay=.0125 userKey
    case ${percnt%?} in
        0.0|33.[36]|49.8|50.1|66.[69]|99.9|100.0) delay=.5 ;;
    esac
    IFS= read -rst $delay -n 1 userKey && case $userKey in
        n ) return 1 ;;
        q ) return 2 ;;
    esac
    return 0
}

chars=( '\U2588\U2589\U258A\U258B\U258C\U258D\U258E\U258F' ''
        '\U2597\U2584\U2596' '\U257A\U2501\U2578' '\U2576\U2500\U2574' \
                             '\U259D\U2580\U2598' '\U2830\U2836\U2806')
mapfile -t printchars < <(printf '%b\n' "${chars[@]:---default--}")
mapfile -t printchars < <(printf '%s\n' "${printchars[@]//?/ &}")
mapfile -t printchars < <(printf '%s\n' "${printchars[@]/# }")

Put here all three functions: percent(){ ..., percentBar(){ ... and percentBar2(){ ..., and

printf '\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\e[20A\e7' &&
for thm in '' '\e[32;1m:\e[0;30m' '\e[38;5;125m:\e[38;5;95m'; do
    thmFg="${thm%:*}" thmBg="${thm#*:}"
    thmBg="${thmBg/\[0;/[}"
    tthm="${thmFg}${thmBg/\[3/[4}"
    tthm="${tthm/m\\e[/;}"
    printThm="${thm:---default--}"
    str="\\e8\e[AColors: \47%s\47 \47%b\U259A\U259A\U259A\U259A\e[0m\47  \47%s"
    str+="\47  \47%b\U259A\U259A\e[0;1m\47:\e[0m\47%b\U259A\U259A\e[0m\47\n"
    printf "$str" "${tthm:---default--}" "$tthm" "${printThm/:/\':\'}" \
           "${thm%:*}" "${thm#*:}"
    for i in {0..9999..11} 10000; do  # {0..9999..33}
        o=0 i=0$i
        printf -v percnt %0.2f "${i::-2}.${i: -2}"
        for l in 1 3 12 $((COLUMNS)); do
            percentBar "$percnt" $l "bar[$((o++))]"
        done
        for char in "${chars[@]:1}"; do
            for l in 1 3 12 $((COLUMNS)); do
                percentBar2 "$percnt" $l "bar[$((o++))]" "$char" "$thm"
            done
        done
        str="Chars: \47%%%%b\47\nWidth 1 char \U2595%%%%%%%%b%s\e[0m\U258F, 3 c"
        str+="hars \U2595%%%%%%%%b%s\e[0m\U258F, 12 chars \U2595%%%%%%%%b%s\e[0"
        str+="m\U258F, or full width:%%7.2f%%%%%%%%%%%%%%%%\n%%%%%%%%b%s\e[0m\n"
        printf -v str "$str"    "${bar[@]}"
        printf -v str "$str" "$percnt"{,,,,,,}
        printf -v str "$str" "${printchars[@]}"
        printf "\e8${str%$'\n'}" "$tthm"{,,,}
        doDelay || break $?
    done
done

Should produce something like:

How to add nice spinner in bash

If you don't have any to create a progress bar, but still want a spinner for ask user to wait, you could simply:

spinner() {
    local shs=( - \\ \| / ) pnt=0
    printf '\e7'
    while ! read -rsn1 -t .2 _; do
        printf '%b\e8' "${shs[pnt++%${#shs[@]}]}"
    done
}
printf '\e[H\e[J Simple spinner: ';spinner

This could be stopped by hitting Any key.

Start / stop spinner as background task

So for using them as a backgroud task, you could use this two wrappers:

startSpinner () { 
    tput civis;
    exec {doSpinner}> >(spinner "$@")
}
stopSpinner () { 
    echo >&"$doSpinner" && exec {doSpinner}>&-;
    tput cnorm;
    echo
}

printf '\e[H\e[J Simple spinner: ';startSpinner;read -rsn 1 -t 4 _;stopSpinner

Then, for sample short stat of $HOME directory:

printf 'Scan %s for stats... ' "$HOME"; \
startSpinner; \
declare -A homeStats; \
while read cnt typ; do
    homeStats["$typ"]=$cnt;
done < <(
    find "$HOME" -printf entries\\n -type f -printf files\\n -o -type d \
        -printf dirs\\n 2>/dev/null | sort | uniq -c); \
stopSpinner; \
printf 'There are %d entries in %s, %d directories, %d files and %d others entries.\n' \
     ${homeStats[entries]} "$HOME" ${homeStats[files]} ${homeStats[dirs]} \
     $(( homeStats[entries] - homeStats[files] - homeStats[dirs] ))

Using UTF-8 braille characters for drawing a spinner

spinner(){
    local pnt=0 shs=( 01 08 10 20 80 40 04 02 )
    printf '\e7'
    while ! read -sn 1 -t .2 _; do
        printf %b\\e8  \\U28${shs[pnt++%${#shs[@]}]}
    done
}

printf '\e[H\e[J Single dot braille: ';startSpinner;read -rsn 1 -t 4 _;stopSpinner

Growing snake spinner

More sophisticated shape, drawing a growing snake:

spinner(){
    local pnt=0 shs=( 01 08 10 20 80 40 04 02 09 18 30 a0 c0 44 06 03 19 38
       b0 e0 c4 46 07 0b 39 b8 f0 e4 c6 47 0f 1b b9 f8 f4 e6 c7 4f 1f 3b f9
       fc f6 e7 cf 5f 3f bb fd fe f7 ef df 7f bf fb f9 fc f6 e7 cf 5f 3f bb
       b9 f8 f4 e6 c7 4f 1f 3b 39 b8 f0 e4 c6 47 0f 1b 19 38 b0 e0 c4 46 07
       0b 09 18 30 a0 c0 44 06 03 )
    printf '\e7'
    while ! read -sn 1 -t .2 _; do
        printf %b\\e8  \\U28${shs[pnt++%${#shs[@]}]}
    done
}

printf '\e[H\e[J Growing snake spinner: ';startSpinner;read -rsn 1 -t 4 _;stopSpinner

Two characters braille snake spinner

This is an auto-build function:

 spinner() {
    local shs=( 100 800 1 8 10 20 80  40 8000  4000 400 200 100  900 801 9 18 30
        A0 C0 8040 C000 4400 600 300 900 901 809 19 38 B0 E0 80C0 C040 C400 4600
        700 B00  901 909 819 39 B8 F0 80E0  C0C0 C440 C600  4700 F00 B01 909 919
        839  B9 F8 80F0 C0E0 C4C0  C640 C700  4F00 F01  B09 919 939  8B9 F9 80F8
        C0F0 C4E0  C6C0 C740 CF00 4F01 F09  B19 939 9B9 8F9 80F9  C0F8 C4F0 C6E0
        C7C0  CF40 CF01 4F09  F19 B39 9B9 9F9 88F9 C0F9 C4F8 C6F0 C7E0 CFC0 CF41
        CF09 4F19 F39 BB9 9F9 89F9 C8F9 C4F9 C6F8 C7F0 CFE0 CFC1 CF49 CF19  4F39
        FB9 BF9 89F9 C9F9 CCF9 C6F9 C7F8  CFF0 CFE1 CFC9 CF59 CF39 4FB9 FF9 8BF9
        C9F9 CDF9 CEF9 C7F9  CFF8 CFF1 CFE9 CFD9  CF79 CFB9 4FF9  8FF9 C9F9 CCF9
        C6F9 C7F8  CFF0 CFE1 CFC9 CF59  CF39 4FB9 FF9  89F9 C8F9 C4F9  C6F8 C7F0
        CFE0  CFC1 CF49 CF19  4F39 FB9 9F9 88F9  C0F9 C4F8  C6F0 C7E0  CFC0 CF41
        CF09 4F19 F39 9B9 8F9 80F9  C0F8 C4F0  C6E0 C7C0 CF40 CF01  4F09 F19 939
        8B9 F9 80F8  C0F0 C4E0 C6C0 C740 CF00 4F01 F09  919 839  B9 F8 80F0 C0E0
        C4C0 C640  C700 4F00 F01 909  819 39 B8 F0 80E0 C0C0 C440 C600  4700 F00
        901 809 19 38 B0 E0 80C0  C040 C400  4600 700 900 801 9 18 30 A0 C0 8040
        C000 4400 600 ) chr
    local -i pnt
    for pnt in "${!shs[@]}"; do
        chr="000${shs[pnt]}"
        printf -v shs[pnt] '%b' "\U28${chr: -4:2}\U28${chr: -2}"
    done
    eval "${FUNCNAME[0]}() { local shs=( ${shs[*]@Q}) "'
             local -i pnt;printf '\''\e7'\'';
         while ! read -rsn1 -t "${1:-.02}"; do
              printf '\''%b\e8'\'' "${shs[pnt++%${#shs[@]}]}";
         done;}';
};spinner

Then:

printf 'Snake two braille chars: ';startSpinner;read -rsn 1 -t 12 _;stopSpinner

If you find this fun, you may found a 8 characters: four columns on two lines growing snake spinner at My eight braille pattern progressive snake spinner ( @ Code Golf ;-)

     ⡎⠉⠉⢹
     ⣇⣀⣀⣸ 

Another practical sample

I've posted a full grep progress bar script answering grep - how to output progress bar or status

• using a spinner while building list of files to grep using shopt -s globstar and files=(**)

• drawing two progress bar:

  • one for file list progression
  • one for each file read (usefull when reading big files)

  Here is a old view of output:
  

• You may found my parallel grep script on my website Here is a screen shot:
  

I was looking for something more sexy than the selected answer, so did my own script.

Preview

Source

I put it on github progress-bar.sh

progress-bar() {
  local duration=${1}


    already_done() { for ((done=0; done<$elapsed; done++)); do printf "▇"; done }
    remaining() { for ((remain=$elapsed; remain<$duration; remain++)); do printf " "; done }
    percentage() { printf "| %s%%" $(( (($elapsed)*100)/($duration)*100/100 )); }
    clean_line() { printf "\r"; }

  for (( elapsed=1; elapsed<=$duration; elapsed++ )); do
      already_done; remaining; percentage
      sleep 1
      clean_line
  done
  clean_line
}

Usage

 progress-bar 100

Some posts have showed how to display the command's progress. In order to calculate it, you'll need to see how much you've progressed. On BSD systems some commands, such as dd(1), accept a SIGINFO signal, and will report their progress. On Linux systems some commands will respond similarly to SIGUSR1. If this facility is available, you can pipe your input through _dd to monitor the number of bytes processed.

Alternatively, you can use lsof to obtain the offset of the file's read pointer, and thereby calculate the progress. Here is an example of using lsof(1) to see the progress of wc(1) reading a large file named blob.

$ wc -l blob &
[1] 3405769

$ lsof -w -o0 -o -c wc
COMMAND     PID USER   FD   TYPE  DEVICE       OFFSET     NODE NAME
[...]
wc      3405769  dds    3r   REG   254,7 0t2656059392  7733716 blob

I've written a command, named pmonitor, that displays the progress of processing a specified process or file. With it you can do things, such as the following.

$ pmonitor -c gzip
/home/dds/data/mysql-2015-04-01.sql.gz 58.06%

An earlier version of Linux and FreeBSD shell scripts appears on my blog ("Monitor Process Progress on Unix").

Haven't seen anything similar and all custom functions here seem to focus on rendering alone so... my very simple POSIX compliant solution below with step by step explanations because this question isn't trivial.

TL;DR

Rendering the progress bar is very easy. Estimating how much of it should render is a different matter. This is how to render (animate) the progress bar - you can copy&paste this example to a file and run it:

#!/bin/sh

BAR='####################'   # this is full bar, e.g. 20 chars

for i in {1..20}; do
    echo -ne "\r${BAR:0:$i}" # print $i chars of $BAR from 0 position
    sleep .1                 # wait 100ms between "frames"
done

• {1..20} - values from 1 to 20
• echo - print to terminal (i.e. to stdout)
• echo -n - print without new line at the end
• echo -e - interpret special characters while printing
• "\r" - carriage return, a special char to return to the beginning of the line

You can make it render any content at any speed so this method is very universal, e.g. often used for visualization of "hacking" in silly movies, no kidding.

Full answer (from zero to working example)

The meat of the problem is how to determine the $i value, i.e. how much of the progress bar to display. In the above example I just let it increment in for loop to illustrate the principle but a real life application would use an infinite loop and calculate the $i variable on each iteration. To make said calculation it needs the following ingredients:

1. how much work there is to be done
2. how much work has been done so far

In case of cp it needs the size of a source file and the size of the target file:

#!/bin/sh

src="/path/to/source/file"
tgt="/path/to/target/file"

cp "$src" "$tgt" &                     # the & forks the `cp` process so the rest
                                       # of the code runs without waiting (async)

BAR='####################'

src_size=$(stat -c%s "$src")           # how much there is to do

while true; do
    tgt_size=$(stat -c%s "$tgt")       # how much has been done so far
    i=$(( $tgt_size * 20 / $src_size ))
    echo -ne "\r${BAR:0:$i}"
    if [ $tgt_size == $src_size ]; then
        echo ""                        # add a new line at the end
        break;                         # break the loop
    fi
    sleep .1
done

• foo=$(bar) - run bar in a subprocess and save its stdout to $foo
• stat - print file stats to stdout
• stat -c - print a formatted value
• %s - format for total size

In case of operations like file unpacking, calculating the source size is slightly more difficult but still as easy as getting the size of an uncompressed file:

#!/bin/sh
src_size=$(gzip -l "$src" | tail -n1 | tr -s ' ' | cut -d' ' -f3)

• gzip -l - print info about zip archive
• tail -n1 - work with 1 line from the bottom
• tr -s ' ' - translate multiple spaces into one ("squeeze" them)
• cut -d' ' -f3 - cut 3rd space-delimited field (column)

Here's the meat of the problem I mentioned before. This solution is less and less general. All calculations of the actual progress are tightly bound to the domain you're trying to visualize, is it a single file operation, a timer countdown, a rising number of files in a directory, operation on multiple files, etc., therefore, it can't be reused. The only reusable part is progress bar rendering. To reuse it you need to abstract it and save in a file (e.g. /usr/lib/progress_bar.sh), then define functions that calculate input values specific to your domain. This is how a generalized code could look like (I also made the $BAR dynamic because people were asking for it, the rest should be clear by now):

#!/bin/bash

BAR_length=50
BAR_character='#'
BAR=$(printf %${BAR_length}s | tr ' ' $BAR_character)

work_todo=$(get_work_todo)             # how much there is to do

while true; do
    work_done=$(get_work_done)         # how much has been done so far
    i=$(( $work_done * $BAR_length / $work_todo ))
    echo -ne "\r${BAR:0:$i}"
    if [ $work_done == $work_todo ]; then
        echo ""
        break;
    fi
    sleep .1
done

• printf - a builtin for printing stuff in a given format
• printf %50s - print nothing but pad it with 50 spaces
• tr ' ' '#' - translate every space to hash sign

And this is how you'd use it:

#!/bin/bash

src="/path/to/source/file"
tgt="/path/to/target/file"

function get_work_todo() {
    echo $(stat -c%s "$src")
}

function get_work_done() {
    [ -e "$tgt" ] &&                   # if target file exists
        echo $(stat -c%s "$tgt") ||    # echo its size, else
        echo 0                         # echo zero
}

cp "$src" "$tgt" &                     # copy in the background

source /usr/lib/progress_bar.sh        # execute the progress bar

Obviously you can wrap this in a function, rewrite to work with piped streams, grab forked process ID with $! and pass it to progress_bar.sh so it could guess how to calculate work to do and work done, whatever's your poison.

Side notes

I get asked about these two things most often:

1. ${}: in above examples I use ${foo:A:B}. The technical term for this syntax is Parameter Expansion, a built-in shell functionality that allows to manipulate a variable (parameter), e.g. to trim a string with : but also to do other things - it does not spawn a subshell. The most prominent description of parameter expansion I can think of (that isn't fully POSIX compatible but lets the reader understand the concept well) is in the man bash page.
2. $(): in above examples I use foo=$(bar). It spawns a separate shell in a subprocess (a.k.a. a Subshell), runs the bar command in it and assigns its standard output to a $foo variable. It's not the same as Process Substitution and it's something entirely different than pipe (|). Most importantly, it works. Some say this should be avoided because it's slow. I argue this is "a okay" here because whatever this code is trying to visualise lasts long enough to require a progress bar. In other words, subshells are not the bottleneck. Calling a subshell also saves me the effort of explaining why return isn't what most people think it is, what is an Exit Status and why passing values from functions in shells is not what shell functions are good at in general. To find out more about all of it I, again, highly recommend the man bash page.

APT style progress bar (Does not break normal output)

EDIT: For an updated version check my github page

I was not satisfied with the responses on this question. What I was personally looking for was a fancy progress bar as is seen by APT.

I had a look at the C source code for APT and decided to write my own equivalent for bash.

This progress bar will stay nicely at the bottom of the terminal and will not interfere with any output sent to the terminal.

Please do note that the bar is currently fixed at 100 characters wide. If you want scale it to the size of the terminal, this is fairly easy to accomplish as well (The updated version on my github page handles this well).

I will post my script here. Usage example:

source ./progress_bar.sh
echo "This is some output"
setup_scroll_area
sleep 1
echo "This is some output 2"
draw_progress_bar 10
sleep 1
echo "This is some output 3"
draw_progress_bar 50
sleep 1
echo "This is some output 4"
draw_progress_bar 90
sleep 1
echo "This is some output 5"
destroy_scroll_area

The script (I strongly recommend the version on my github instead):

#!/bin/bash

# This code was inspired by the open source C code of the APT progress bar
# http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/trusty/apt/trusty/view/head:/apt-pkg/install-progress.cc#L233

#
# Usage:
# Source this script
# setup_scroll_area
# draw_progress_bar 10
# draw_progress_bar 90
# destroy_scroll_area
#


CODE_SAVE_CURSOR="\033[s"
CODE_RESTORE_CURSOR="\033[u"
CODE_CURSOR_IN_SCROLL_AREA="\033[1A"
COLOR_FG="\e[30m"
COLOR_BG="\e[42m"
RESTORE_FG="\e[39m"
RESTORE_BG="\e[49m"

function setup_scroll_area() {
    lines=$(tput lines)
    let lines=$lines-1
    # Scroll down a bit to avoid visual glitch when the screen area shrinks by one row
    echo -en "\n"

    # Save cursor
    echo -en "$CODE_SAVE_CURSOR"
    # Set scroll region (this will place the cursor in the top left)
    echo -en "\033[0;${lines}r"

    # Restore cursor but ensure its inside the scrolling area
    echo -en "$CODE_RESTORE_CURSOR"
    echo -en "$CODE_CURSOR_IN_SCROLL_AREA"

    # Start empty progress bar
    draw_progress_bar 0
}

function destroy_scroll_area() {
    lines=$(tput lines)
    # Save cursor
    echo -en "$CODE_SAVE_CURSOR"
    # Set scroll region (this will place the cursor in the top left)
    echo -en "\033[0;${lines}r"

    # Restore cursor but ensure its inside the scrolling area
    echo -en "$CODE_RESTORE_CURSOR"
    echo -en "$CODE_CURSOR_IN_SCROLL_AREA"

    # We are done so clear the scroll bar
    clear_progress_bar

    # Scroll down a bit to avoid visual glitch when the screen area grows by one row
    echo -en "\n\n"
}

function draw_progress_bar() {
    percentage=$1
    lines=$(tput lines)
    let lines=$lines
    # Save cursor
    echo -en "$CODE_SAVE_CURSOR"

    # Move cursor position to last row
    echo -en "\033[${lines};0f"

    # Clear progress bar
    tput el

    # Draw progress bar
    print_bar_text $percentage

    # Restore cursor position
    echo -en "$CODE_RESTORE_CURSOR"
}

function clear_progress_bar() {
    lines=$(tput lines)
    let lines=$lines
    # Save cursor
    echo -en "$CODE_SAVE_CURSOR"

    # Move cursor position to last row
    echo -en "\033[${lines};0f"

    # clear progress bar
    tput el

    # Restore cursor position
    echo -en "$CODE_RESTORE_CURSOR"
}

function print_bar_text() {
    local percentage=$1

    # Prepare progress bar
    let remainder=100-$percentage
    progress_bar=$(echo -ne "["; echo -en "${COLOR_FG}${COLOR_BG}"; printf_new "#" $percentage; echo -en "${RESTORE_FG}${RESTORE_BG}"; printf_new "." $remainder; echo -ne "]");

    # Print progress bar
    if [ $1 -gt 99 ]
    then
        echo -ne "${progress_bar}"
    else
        echo -ne "${progress_bar}"
    fi
}

printf_new() {
    str=$1
    num=$2
    v=$(printf "%-${num}s" "$str")
    echo -ne "${v// /$str}"
}

GNU tar has a useful option which gives a functionality of a simple progress bar.

(...) Another available checkpoint action is ‘dot’ (or ‘.’). It instructs tar to print a single dot on the standard listing stream, e.g.:

$ tar -c --checkpoint=1000 --checkpoint-action=dot /var
...

The same effect may be obtained by:

$ tar -c --checkpoint=.1000 /var

A simpler method that works on my system using the pipeview ( pv ) utility.

srcdir=$1
outfile=$2


tar -Ocf - $srcdir | pv -i 1 -w 50 -berps `du -bs $srcdir | awk '{print $1}'` | 7za a -si $outfile

Here is how it might look

Uploading a file

[##################################################] 100% (137921 / 137921 bytes)

Waiting for a job to complete

[#########################                         ] 50% (15 / 30 seconds)

Simple function that implements it

You can just copy-paste it to your script. It does not require anything else to work.

PROGRESS_BAR_WIDTH=50  # progress bar length in characters

draw_progress_bar() {
  # Arguments: current value, max value, unit of measurement (optional)
  local __value=$1
  local __max=$2
  local __unit=${3:-""}  # if unit is not supplied, do not display it

  # Calculate percentage
  if (( $__max < 1 )); then __max=1; fi  # anti zero division protection
  local __percentage=$(( 100 - ($__max*100 - $__value*100) / $__max ))

  # Rescale the bar according to the progress bar width
  local __num_bar=$(( $__percentage * $PROGRESS_BAR_WIDTH / 100 ))

  # Draw progress bar
  printf "["
  for b in $(seq 1 $__num_bar); do printf "#"; done
  for s in $(seq 1 $(( $PROGRESS_BAR_WIDTH - $__num_bar ))); do printf " "; done
  printf "] $__percentage%% ($__value / $__max $__unit)\r"
}

Usage example

Here, we upload a file and redraw the progress bar at each iteration. It does not matter what job is actually performed as long as we can get 2 values: max value and current value.

In the example below the max value is file_size and the current value is supplied by some function and is called uploaded_bytes.

# Uploading a file
file_size=137921

while true; do
  # Get current value of uploaded bytes
  uploaded_bytes=$(some_function_that_reports_progress)

  # Draw a progress bar
  draw_progress_bar $uploaded_bytes $file_size "bytes"

  # Check if we reached 100%
  if [ $uploaded_bytes == $file_size ]; then break; fi
  sleep 1  # Wait before redrawing
done
# Go to the newline at the end of upload
printf "\n"

This lets you visualize that a command is still executing:

while :;do echo -n .;sleep 1;done &
trap "kill $!" EXIT  #Die with parent if we die prematurely
tar zxf packages.tar.gz; # or any other command here
kill $! && trap " " EXIT #Kill the loop and unset the trap or else the pid might get reassigned and we might end up killing a completely different process

This will create an infinite while loop that executes in the background and echoes a "." every second. This will display . in the shell. Run the tar command or any a command you want. When that command finishes executing then kill the last job running in the background - which is the infinite while loop.

I needed a progress bar for iterating over the lines in a csv file. Was able to adapt cprn's code into something useful for me:

BAR='##############################'
FILL='------------------------------'
totalLines=$(wc -l $file | awk '{print $1}')  # num. lines in file
barLen=30

# --- iterate over lines in csv file ---
count=0
while IFS=, read -r _ col1 col2 col3; do
    # update progress bar
    count=$(($count + 1))
    percent=$((($count * 100 / $totalLines * 100) / 100))
    i=$(($percent * $barLen / 100))
    echo -ne "\r[${BAR:0:$i}${FILL:$i:barLen}] $count/$totalLines ($percent%)"

    # other stuff
    (...)
done <$file

Looks like this:

[##----------------------------] 17128/218210 (7%)

I needed a progress bar that would fit in popup bubble message (notify-send) to represent TV volume level. Recently I've been writing a music player in python and the TV picture is turned off most of the time.

Sample output from terminal

Bash script

#!/bin/bash

# Show a progress bar at step number $1 (from 0 to 100)


function is_int() { test "$@" -eq "$@" 2> /dev/null; } 

# Parameter 1 must be integer
if ! is_int "$1" ; then
   echo "Not an integer: ${1}"
   exit 1
fi

# Parameter 1 must be >= 0 and <= 100
if [ "$1" -ge 0 ] && [ "$1" -le 100 ]  2>/dev/null
then
    :
else
    echo bad volume: ${1}
    exit 1
fi

# Main function designed for quickly copying to another program 
Main () {

    Bar=""                      # Progress Bar / Volume level
    Len=25                      # Length of Progress Bar / Volume level
    Div=4                       # Divisor into Volume for # of blocks
    Fill="▒"                    # Fill up to $Len
    Arr=( "▉" "▎" "▌" "▊" )     # UTF-8 left blocks: 7/8, 1/4, 1/2, 3/4

    FullBlock=$((${1} / Div))   # Number of full blocks
    PartBlock=$((${1} % Div))   # Size of partial block (array index)

    while [[ $FullBlock -gt 0 ]]; do
        Bar="$Bar${Arr[0]}"     # Add 1 full block into Progress Bar
        (( FullBlock-- ))       # Decrement full blocks counter
    done

    # If remainder zero no partial block, else append character from array
    if [[ $PartBlock -gt 0 ]]; then
        Bar="$Bar${Arr[$PartBlock]}"
    fi

    while [[ "${#Bar}" -lt "$Len" ]]; do
        Bar="$Bar$Fill"         # Pad Progress Bar with fill character
    done

    echo Volume: "$1 $Bar"
    exit 0                      # Remove this line when copying into program
} # Main

Main "$@"

Test bash script

Use this script to test the progress bar in the terminal.

#!/bin/bash

# test_progress_bar3

Main () {

    tput civis                              # Turn off cursor
    for ((i=0; i<=100; i++)); do
        CurrLevel=$(./progress_bar3 "$i")   # Generate progress bar 0 to 100
        echo -ne "$CurrLevel"\\r            # Reprint overtop same line
        sleep .04
    done
    echo -e \\n                             # Advance line to keep last progress
    echo "$0 Done"
    tput cnorm                              # Turn cursor back on
} # Main

Main "$@"

TL;DR

This section details how notify-send is used to quickly spam popup bubble messages to the desktop. This is required because volume level can change many times a second and the default bubble message behavior is for a message to stay on the desktop for many seconds.

Sample popup bubble message

Popup bubble message bash code

From the script above the main function was copied to a new functioned called VolumeBar in an existing bash script called tvpowered. The exit 0 command in the copied main function was removed.

Here's how to call it and let Ubuntu's notify-send command know we will be spamming popup bubble message:

VolumeBar $CurrVolume
# Ask Ubuntu: https://askubuntu.com/a/871207/307523
notify-send --urgency=critical "tvpowered" \
    -h string:x-canonical-private-synchronous:volume \
    --icon=/usr/share/icons/gnome/48x48/devices/audio-speakers.png \
    "Volume: $CurrVolume $Bar"

This is the new line which tells notify-send to immediately replace last popup bubble:

-h string:x-canonical-private-synchronous:volume \

volume groups the popup bubble messages together and new messages in this group immediately replaces the previous. You can use anything instead of volume.

Most unix commands will not give you the sort of direct feedback from which you can do this. Some will give you output on stdout or stderr that you can use.

For something like tar you could use the -v switch and pipe the output to a program that updates a small animation for each line it reads. As tar writes out a list of files it's unravelled the program can update the animation. To do a percent complete you would have to know the number of files and count the lines.

cp doesn't give this sort of output as far as I know. To monitor the progress of cp you would have to monitor the source and destination files and watch the size of the destination. You could write a small c program using the stat (2) system call to get the file size. This would read the size of the source then poll the destination file and update a % complete bar based on the size of the file written to date.

First of all bar is not the only one pipe progress meter. The other (maybe even more known) is pv (pipe viewer).

Secondly bar and pv can be used for example like this:

$ bar file1 | wc -l 
$ pv file1 | wc -l

or even:

$ tail -n 100 file1 | bar | wc -l
$ tail -n 100 file1 | pv | wc -l

one useful trick if you want to make use of bar and pv in commands that are working with files given in arguments, like e.g. copy file1 file2, is to use process substitution:

$ copy <(bar file1) file2
$ copy <(pv file1) file2

Process substitution is a bash magic thing that creates temporary fifo pipe files /dev/fd/ and connect stdout from runned process (inside parenthesis) through this pipe and copy sees it just like an ordinary file (with one exception, it can only read it forwards).

Update:

bar command itself allows also for copying. After man bar:

bar --in-file /dev/rmt/1cbn --out-file \
     tape-restore.tar --size 2.4g --buffer-size 64k

But process substitution is in my opinion more generic way to do it. An it uses cp program itself.

Based on the work of Edouard Lopez, I created a progress bar that fits the size of the screen, whatever it is. Check it out.

It's also posted on Git Hub.

#!/bin/bash
#
# Progress bar by Adriano Pinaffo
# Available at https://github.com/adriano-pinaffo/progressbar.sh
# Inspired on work by Edouard Lopez (https://github.com/edouard-lopez/progress-bar.sh)
# Version 1.0
# Date April, 28th 2017

function error {
  echo "Usage: $0 [SECONDS]"
  case $1 in
    1) echo "Pass one argument only"
    exit 1
    ;;
    2) echo "Parameter must be a number"
    exit 2
    ;;
    *) echo "Unknown error"
    exit 999
  esac
}

[[ $# -ne 1 ]] && error 1
[[ $1 =~ ^[0-9]+$ ]] || error 2

duration=${1}
barsize=$((`tput cols` - 7))
unity=$(($barsize / $duration))
increment=$(($barsize%$duration))
skip=$(($duration/($duration-$increment)))
curr_bar=0
prev_bar=
for (( elapsed=1; elapsed<=$duration; elapsed++ ))
do
  # Elapsed
prev_bar=$curr_bar
  let curr_bar+=$unity
  [[ $increment -eq 0 ]] || {  
    [[ $skip -eq 1 ]] &&
      { [[ $(($elapsed%($duration/$increment))) -eq 0 ]] && let curr_bar++; } ||
    { [[ $(($elapsed%$skip)) -ne 0 ]] && let curr_bar++; }
  }
  [[ $elapsed -eq 1 && $increment -eq 1 && $skip -ne 1 ]] && let curr_bar++
  [[ $(($barsize-$curr_bar)) -eq 1 ]] && let curr_bar++
  [[ $curr_bar -lt $barsize ]] || curr_bar=$barsize
  for (( filled=0; filled<=$curr_bar; filled++ )); do
    printf "▇"
  done

  # Remaining
  for (( remain=$curr_bar; remain<$barsize; remain++ )); do
    printf " "
  done

  # Percentage
  printf "| %s%%" $(( ($elapsed*100)/$duration))

  # Return
  sleep 1
  printf "\r"
done
printf "\n"
exit 0

Enjoy

My solution displays the percentage of the tarball that is currently being uncompressed and written. I use this when writing out 2GB root filesystem images. You really need a progress bar for these things. What I do is use gzip --list to get the total uncompressed size of the tarball. From that I calculate the blocking-factor needed to divide the file into 100 parts. Finally, I print a checkpoint message for each block. For a 2GB file this gives about 10MB a block. If that is too big then you can divide the BLOCKING_FACTOR by 10 or 100, but then it's harder to print pretty output in terms of a percentage.

Assuming you are using Bash then you can use the following shell function

untar_progress () 
{ 
  TARBALL=$1
  BLOCKING_FACTOR=$(gzip --list ${TARBALL} |
    perl -MPOSIX -ane '$.==2 && print ceil $F[1]/50688')
  tar --blocking-factor=${BLOCKING_FACTOR} --checkpoint=1 \
    --checkpoint-action='ttyout=Wrote %u%  \r' -zxf ${TARBALL}
}

Many answers describe writing your own commands for printing out '\r' + $some_sort_of_progress_msg. The problem sometimes is that printing out hundreds of these updates per second will slow down the process.

However, if any of your processes produce output (eg 7z a -r newZipFile myFolder will output each filename as it compresses it) then a simpler, fast, painless and customisable solution exists.

Install the python module tqdm.

$ sudo pip install tqdm
$ # now have fun
$ 7z a -r -bd newZipFile myFolder | tqdm >> /dev/null
$ # if we know the expected total, we can have a bar!
$ 7z a -r -bd newZipFile myFolder | grep -o Compressing | tqdm --total $(find myFolder -type f | wc -l) >> /dev/null

Help: tqdm -h. An example using more options:

$ find / -name '*.py' -exec cat \{} \; | tqdm --unit loc --unit_scale True | wc -l

As a bonus you can also use tqdm to wrap iterables in python code.

https://github.com/tqdm/tqdm/blob/master/README.rst#module

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"

This is only applicable using gnome zenity. Zenity provides a great native interface to bash scripts: https://help.gnome.org/users/zenity/stable/

From Zenity Progress Bar Example:

#!/bin/sh
(
echo "10" ; sleep 1
echo "# Updating mail logs" ; sleep 1
echo "20" ; sleep 1
echo "# Resetting cron jobs" ; sleep 1
echo "50" ; sleep 1
echo "This line will just be ignored" ; sleep 1
echo "75" ; sleep 1
echo "# Rebooting system" ; sleep 1
echo "100" ; sleep 1
) |
zenity --progress \
  --title="Update System Logs" \
  --text="Scanning mail logs..." \
  --percentage=0

if [ "$?" = -1 ] ; then
        zenity --error \
          --text="Update canceled."
fi

To indicate progress of activity, try the following commands:

while true; do sleep 0.25 && echo -ne "\r\\" && sleep 0.25 && echo -ne "\r|" && sleep 0.25 && echo -ne "\r/" && sleep 0.25 && echo -ne "\r-"; done;

OR

while true; do sleep 0.25 && echo -ne "\rActivity: \\" && sleep 0.25 && echo -ne "\rActivity: |" && sleep 0.25 && echo -ne "\rActivity: /" && sleep 0.25 && echo -ne "\rActivity: -"; done;

OR

while true; do sleep 0.25 && echo -ne "\r" && sleep 0.25 && echo -ne "\r>" && sleep 0.25 && echo -ne "\r>>" && sleep 0.25 && echo -ne "\r>>>"; sleep 0.25 && echo -ne "\r>>>>"; done;

OR

while true; do sleep .25 && echo -ne "\r:Active:" && sleep .25 && echo -ne "\r:aCtive:" && sleep .25 && echo -ne "\r:acTive:" && sleep .25 && echo -ne "\r:actIve:" && sleep .25 && echo -ne "\r:actiVe:" && sleep .25 && echo -ne "\r:activE:"; done;

One can use flags/variables inside the while loop to check and display the value/extent of progress.

https://github.com/extensionsapp/progre.sh

Create 40 percent progress: progreSh 40

It may be achieved in a pretty simple way:

• iterate from 0 to 100 with for loop
• sleep every step for 25ms (0.25 second)
• append to the $bar variable another = sign to make the progress bar wider
• echo progress bar and percentage (\r cleans line and returns to the beginning of the line; -ne makes echo doesn't add newline at the end and parses \r special character)

function progress {
    bar=''
    for (( x=0; x <= 100; x++ )); do
        sleep 0.25
        bar="${bar}="
        echo -ne "$bar ${x}%\r"
    done
    echo -e "\n"
}

$ progress
> ========== 10% # here: after 2.5 seconds

$ progress
> ============================== 30% # here: after 7.5 seconds

COLORED PROGRESS BAR

function progress {
    bar=''
    for (( x=0; x <= 100; x++ )); do
        sleep 0.05
        bar="${bar} "

        echo -ne "\r"
        echo -ne "\e[43m$bar\e[0m"

        local left="$(( 100 - $x ))"
        printf " %${left}s"
        echo -n "${x}%"
    done
    echo -e "\n"
}

To make a progress bar colorful, you can use formatting escape sequence - here the progress bar is yellow: \e[43m, then we reset custom settings with \e[0m, otherwise it would affect further input even when the progress bar is done.

for me easiest to use and best looking so far is command pv or bar like some guy already wrote

for example: need to make a backup of entire drive with dd

normally you use dd if="$input_drive_path" of="$output_file_path"

with pv you can make it like this :

dd if="$input_drive_path" | pv | dd of="$output_file_path"

and the progress goes directly to STDOUT as this:

    7.46GB 0:33:40 [3.78MB/s] [  <=>                                            ]

after it is done summary comes up

    15654912+0 records in
    15654912+0 records out
    8015314944 bytes (8.0 GB) copied, 2020.49 s, 4.0 MB/s

I used an answer from Creating string of repeated characters in shell script for char repeating. I have two relatively small bash versions for scripts that need to display progress bar (for example, a loop that goes through many files, but not useful for big tar files or copy operations). The faster one consists of two functions, one to prepare the strings for bar display:

preparebar() {
# $1 - bar length
# $2 - bar char
    barlen=$1
    barspaces=$(printf "%*s" "$1")
    barchars=$(printf "%*s" "$1" | tr ' ' "$2")
}

and one to display a progress bar:

progressbar() {
# $1 - number (-1 for clearing the bar)
# $2 - max number
    if [ $1 -eq -1 ]; then
        printf "\r  $barspaces\r"
    else
        barch=$(($1*barlen/$2))
        barsp=$((barlen-barch))
        printf "\r[%.${barch}s%.${barsp}s]\r" "$barchars" "$barspaces"
    fi
}

It could be used as:

preparebar 50 "#"

which means prepare strings for bar with 50 "#" characters, and after that:

progressbar 35 80

will display the number of "#" characters that corresponds to 35/80 ratio:

[#####################                             ]

Be aware that function displays the bar on the same line over and over until you (or some other program) prints a newline. If you put -1 as first parameter, the bar would be erased:

progressbar -1 80

The slower version is all in one function:

progressbar() {
# $1 - number
# $2 - max number
# $3 - number of '#' characters
    if [ $1 -eq -1 ]; then
        printf "\r  %*s\r" "$3"
    else
        i=$(($1*$3/$2))
        j=$(($3-i))
        printf "\r[%*s" "$i" | tr ' ' '#'
        printf "%*s]\r" "$j"
    fi
}

and it can be used as (the same example as above):

progressbar 35 80 50

If you need progressbar on stderr, just add >&2 at the end of each printf command.

Using suggestions listed above, I decided to implement my own progress bar.

#!/usr/bin/env bash

main() {
  for (( i = 0; i <= 100; i=$i + 1)); do
    progress_bar "$i"
    sleep 0.1;
  done
  progress_bar "done"
  exit 0
}

progress_bar() {
  if [ "$1" == "done" ]; then
    spinner="X"
    percent_done="100"
    progress_message="Done!"
    new_line="\n"
  else
    spinner='/-\|'
    percent_done="${1:-0}"
    progress_message="$percent_done %"
  fi

  percent_none="$(( 100 - $percent_done ))"
  [ "$percent_done" -gt 0 ] && local done_bar="$(printf '#%.0s' $(seq -s ' ' 1 $percent_done))"
  [ "$percent_none" -gt 0 ] && local none_bar="$(printf '~%.0s' $(seq -s ' ' 1 $percent_none))"

  # print the progress bar to the screen
  printf "\r Progress: [%s%s] %s %s${new_line}" \
    "$done_bar" \
    "$none_bar" \
    "${spinner:x++%${#spinner}:1}" \
    "$progress_message"
}

main "$@"

Flexible version with randomized colors, a string to manipulate and date.

function spinner() {
  local PID="$1"
  local str="${2:-Processing!}"
  local delay="0.1"
  # tput civis  # hide cursor
  while ( kill -0 $PID 2>/dev/null )
    do
      printf "\e[38;5;$((RANDOM%257))m%s\r\e[0m" "[$(date '+%d/%m/%Y %H:%M:%S')][ 🙉  🙊  🙈 $str 🙈  🙊  🙉 ]"; sleep "$delay"
      printf "\e[38;5;$((RANDOM%257))m%s\r\e[0m" "[$(date '+%d/%m/%Y %H:%M:%S')][ 🙈  🙉  🙉 $str 🙊  🙉  🙈 ]"; sleep "$delay"
      printf "\e[38;5;$((RANDOM%257))m%s\r\e[0m" "[$(date '+%d/%m/%Y %H:%M:%S')][ 🙊  🙈  🙊 $str 🙉  🙈  🙊 ]"; sleep "$delay"
  done
  printf "\e[38;5;$((RANDOM%257))m%s\r\e[0m" "[$(date '+%d/%m/%Y %H:%M:%S')][ ✅  ✅  ✅   Done!   ✅  ✅  ✅ ]"; sleep "$delay"
  # tput cnorm  # restore cursor

  return 0
}

Usage:

# your long running proccess pushed to the background
sleep 20 &

# spinner capture-previous-proccess-id string
spinner $! 'Working!'

output example:

[04/06/2020 03:22:24][ 🙊  🙈  🙊 Seeding! 🙉  🙈  🙊 ]

I did a pure shell version for an embedded system taking advantage of:

• /usr/bin/dd's SIGUSR1 signal handling feature.

  Basically, if you send a 'kill SIGUSR1 $(pid_of_running_dd_process)', it'll output a summary of throughput speed and amount transferred.

• backgrounding dd and then querying it regularly for updates, and generating hash ticks like old-school ftp clients used to.

• Using /dev/stdout as the destination for non-stdout friendly programs like scp

The end result allows you to take any file transfer operation and get progress update that looks like old-school FTP 'hash' output where you'd just get a hash mark for every X bytes.

This is hardly production quality code, but you get the idea. I think it's cute.

For what it's worth, the actual byte-count might not be reflected correctly in the number of hashes - you may have one more or less depending on rounding issues. Don't use this as part of a test script, it's just eye-candy. And, yes, I'm aware this is terribly inefficient - it's a shell script and I make no apologies for it.

Examples with wget, scp and tftp provided at the end. It should work with anything that has emits data. Make sure to use /dev/stdout for programs that aren't stdout friendly.

#!/bin/sh
#
# Copyright (C) Nathan Ramella ([email protected]) 2010 
# LGPLv2 license
# If you use this, send me an email to say thanks and let me know what your product
# is so I can tell all my friends I'm a big man on the internet!

progress_filter() {

        local START=$(date +"%s")
        local SIZE=1
        local DURATION=1
        local BLKSZ=51200
        local TMPFILE=/tmp/tmpfile
        local PROGRESS=/tmp/tftp.progress
        local BYTES_LAST_CYCLE=0
        local BYTES_THIS_CYCLE=0

        rm -f ${PROGRESS}

        dd bs=$BLKSZ of=${TMPFILE} 2>&1 \
                | grep --line-buffered -E '[[:digit:]]* bytes' \
                | awk '{ print $1 }' >> ${PROGRESS} &

        # Loop while the 'dd' exists. It would be 'more better' if we
        # actually looked for the specific child ID of the running 
        # process by identifying which child process it was. If someone
        # else is running dd, it will mess things up.

        # My PID handling is dumb, it assumes you only have one running dd on
        # the system, this should be fixed to just get the PID of the child
        # process from the shell.

        while [ $(pidof dd) -gt 1 ]; do

                # PROTIP: You can sleep partial seconds (at least on linux)
                sleep .5    

                # Force dd to update us on it's progress (which gets
                # redirected to $PROGRESS file.
                # 
                # dumb pid handling again
                pkill -USR1 dd

                local BYTES_THIS_CYCLE=$(tail -1 $PROGRESS)
                local XFER_BLKS=$(((BYTES_THIS_CYCLE-BYTES_LAST_CYCLE)/BLKSZ))

                # Don't print anything unless we've got 1 block or more.
                # This allows for stdin/stderr interactions to occur
                # without printing a hash erroneously.

                # Also makes it possible for you to background 'scp',
                # but still use the /dev/stdout trick _even_ if scp
                # (inevitably) asks for a password. 
                #
                # Fancy!

                if [ $XFER_BLKS -gt 0 ]; then
                        printf "#%0.s" $(seq 0 $XFER_BLKS)
                        BYTES_LAST_CYCLE=$BYTES_THIS_CYCLE
                fi
        done

        local SIZE=$(stat -c"%s" $TMPFILE)
        local NOW=$(date +"%s")

        if [ $NOW -eq 0 ]; then
                NOW=1
        fi

        local DURATION=$(($NOW-$START))
        local BYTES_PER_SECOND=$(( SIZE / DURATION ))
        local KBPS=$((SIZE/DURATION/1024))
        local MD5=$(md5sum $TMPFILE | awk '{ print $1 }')

        # This function prints out ugly stuff suitable for eval() 
        # rather than a pretty string. This makes it a bit more 
        # flexible if you have a custom format (or dare I say, locale?)

        printf "\nDURATION=%d\nBYTES=%d\nKBPS=%f\nMD5=%s\n" \
            $DURATION \
            $SIZE \
            $KBPS \
            $MD5
}

Examples:

echo "wget"
wget -q -O /dev/stdout http://www.blah.com/somefile.zip | progress_filter

echo "tftp"
tftp -l /dev/stdout -g -r something/firmware.bin 192.168.1.1 | progress_filter

echo "scp"
scp [email protected]:~/myfile.tar /dev/stdout | progress_filter