您可以通过重写一行来实现这一点。使用\r返回到行首，而不向终端写入\n。

当你完成时，写\n来推进行。

使用echo -ne:

不打印\n和 识别像\r这样的转义序列。

下面是一个演示:

echo -ne '#####                     (33%)\r'
sleep 1
echo -ne '#############             (66%)\r'
sleep 1
echo -ne '#######################   (100%)\r'
echo -ne '\n'

在下面的评论中，puk提到，如果您以长行开始，然后想要编写短行，那么这种方法“失败”:在这种情况下，您将需要覆盖长行的长度(例如，使用空格)。

我以“恐惧之边”提供的答案为基础

它连接到Oracle数据库以检索RMAN恢复的进度。

#!/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}%%"

}

function rman_check {
sqlplus -s / as sysdba <<EOF
set heading off
set feedback off
select
round((sofar/totalwork) * 100,0) pct_done
from
v\$session_longops
where
totalwork > sofar
AND
opname NOT LIKE '%aggregate%'
AND
opname like 'RMAN%';
exit
EOF
}

# Variables
_start=1

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

_rman_progress=$(rman_check)
#echo ${_rman_progress}

# Proof of concept
#for number in $(seq ${_start} ${_end})

while [ ${_rman_progress} -lt 100 ]
do

for number in _rman_progress
do
sleep 10
ProgressBar ${number} ${_end}
done

_rman_progress=$(rman_check)

done
printf '\nFinished!\n'

我需要一个进度条，将适合弹出气泡消息(通知-发送)，以代表电视音量水平。最近我一直在用python写一个音乐播放器，而电视画面大部分时间都是关闭的。

终端输出样本

Bash脚本

#!/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 "$@"

测试bash脚本

使用此脚本测试终端中的进度条。

#!/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 "$@"

博士TL;

本节详细介绍如何使用notify-send将弹出气泡消息快速发送到桌面。这是必需的，因为音量级别可以在一秒钟内更改多次，并且默认的气泡消息行为是让消息在桌面上停留许多秒。

示例弹出气泡消息

弹出气泡消息bash代码

从上面的脚本中，主函数被复制到一个名为tvpowered的现有bash脚本中名为VolumeBar的新函数。已删除复制的主函数中的exit 0命令。

下面是如何调用它并让Ubuntu的notify-send命令知道我们将发送弹出泡泡消息:

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"

这是一个新的行，它告诉notify-send立即替换上一个弹出气泡:

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

卷将弹出气泡消息分组在一起，该组中的新消息立即替换前一个消息。你可以用任何东西来代替体积。

你可能也对如何做一个旋转器感兴趣:

我能在Bash中做旋转吗?

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

#!/bin/bash

function progress_bar() {
    bar=""
    total=10
    [[ -z $1 ]] && input=0 || input=${1}
    x="##"
   for i in `seq 1 10`; do
        if [ $i -le $input ] ;then
            bar=$bar$x
        else
            bar="$bar  "
       fi
    done
    #pct=$((200*$input/$total % 2 + 100*$input/$total))
    pct=$(($input*10))
    echo -ne "Progress : [ ${bar} ] (${pct}%) \r"    
    sleep 1
    if [ $input -eq 10 ] ;then
        echo -ne '\n'
    fi

}

可以创建一个函数，以1-10的比例绘制bar数:

progress_bar 1
echo "doing something ..."
progress_bar 2
echo "doing something ..."
progress_bar 3
echo "doing something ..."
progress_bar 8
echo "doing something ..."
progress_bar 10

要指示活动的进度，请尝试以下命令:

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;

可以在while循环中使用标志/变量来检查和显示进度的值/范围。