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。

这可以让你看到命令仍在执行:

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

这将创建一个无限while循环，在后台执行，并每秒回显一个"."。这将显示出来。在壳里。运行tar命令或任何您需要的命令。当该命令执行完毕时，终止在后台运行的最后一个作业——即无限while循环。

GNU tar有一个有用的选项，它提供了一个简单的进度条功能。

(…)另一个可用的检查点操作是' dot '(或' . ')。它指示tar在标准列表流上打印单个点，例如:

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

同样的效果可以通过:

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

我更喜欢使用dialog和——gauge参数。在许多发行版的.deb包安装和其他基本配置中经常使用。所以你不需要重新发明轮子……再一次

只要输入一个从1到100的int值@stdin。举个简单而愚蠢的例子:

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

我有这个/bin/Wait文件(带有chmod u+x perms)用于烹饪

#!/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"

所以我可以写:

等"34分钟" "预热烤箱"

or

等待“12月31日”“新年快乐”

这是它看起来的样子

上传文件

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

等待一项工作完成

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

实现它的简单函数

你可以复制粘贴到你的脚本。它不需要任何其他东西来工作。

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"
}

使用的例子

在这里，我们上传一个文件，并在每次迭代时重新绘制进度条。只要我们能得到两个值:最大值和当前值，实际执行的作业是什么并不重要。

在下面的例子中，最大值是file_size，当前值由某个名为uploaded_bytes的函数提供。

# 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"

我为嵌入式系统做了一个纯shell版本，利用了:

/usr/bin/dd的SIGUSR1信号处理特性。 基本上，如果您发送'kill SIGUSR1 $(pid_of_running_dd_process)'，它将输出 吞吐量速度和传输量的摘要。 后台dd，然后定期查询它的更新，并生成 像老式的FTP客户端一样。 使用/dev/stdout作为非stdout友好程序(如scp)的目的地

最终的结果允许你进行任何文件传输操作，并获得进度更新，看起来像老式的FTP“哈希”输出，在那里你只需要为每个X字节获得一个哈希标记。

这几乎不是产品质量代码，但您可以理解。我觉得很可爱。

不管怎样，实际的字节计数可能不会正确地反映在哈希数中——根据舍入问题，可能会多一个或少一个。不要将它用作测试脚本的一部分，它只是花瓶。而且，是的，我知道这是非常低效的——这是一个shell脚本，我不为此道歉。

最后提供了使用wget、scp和tftp的示例。它应该与任何发出数据的东西一起工作。确保对标准输出不友好的程序使用/dev/stdout。

#!/bin/sh
#
# Copyright (C) Nathan Ramella (nar+progress-script@remix.net) 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
}

例子:

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 user@192.168.1.1:~/myfile.tar /dev/stdout | progress_filter