当在bash或*NIX中的任何其他shell中编写脚本时,在运行需要超过几秒钟时间的命令时,需要一个进度条。

例如,复制一个大文件,打开一个大tar文件。

你建议用什么方法向shell脚本添加进度条?


当前回答

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

其他回答

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

没有看到任何类似的东西,这里所有的自定义函数似乎都只关注渲染,所以……下面是我非常简单的POSIX兼容解决方案,并逐级解释,因为这个问题并不简单。

博士TL;

渲染进度条非常简单。估计它应该渲染多少是另一回事。这是如何渲染(动画)进度条-你可以复制粘贴这个例子到一个文件并运行它:

#!/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}—取值为1到20 回显-打印到终端(即输出到标准输出) Echo -n -打印结尾没有新行 Echo -e -在打印时解释特殊字符 "\r" -回车,返回行首的特殊字符

你可以让它以任何速度渲染任何内容,所以这种方法是非常通用的,例如,经常用于愚蠢的电影中的可视化“黑客”,没有开玩笑。

完整答案(从0到工作示例)

问题的核心是如何确定$i值,即显示多少进度条。在上面的例子中,我只是让它在for循环中递增以说明原理,但实际应用程序将使用无限循环并在每次迭代中计算$ I变量。要进行上述计算,需要以下成分:

有多少工作要做 到目前为止已经做了多少工作

对于cp,它需要源文件的大小和目标文件的大小:

#!/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 =$(bar) -在子进程中运行bar并将其标准输出保存到$ Foo 打印文件统计到标准输出 打印格式化的值 %s -总大小的格式

对于像文件解包这样的操作,计算源文件大小稍微困难一些,但仍然像获得未压缩文件的大小一样简单:

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

Gzip -l打印关于zip存档的信息 尾部-n1 -从底部开始画一条线 Tr -s ' ' -将多个空格转换为一个(“挤压”它们) Cut -d' ' -f3 -切割第三个以空格分隔的字段(列)

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 -用于打印给定格式的东西的内置程序 打印%50s -只打印50个空格 Tr ' ' '#' -将每个空格转换为散列号

你可以这样使用它:

#!/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

显然,你可以把它包装在一个函数中,重写以使用管道流,用$!然后把它传递给progress_bar。sh这样它就能猜出如何计算要做的功和已经完成的功,不管你想要什么。

一边笔记

我经常被问到这两件事:

${}: 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. $(): in above examples I use foo=$(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.

故障排除

如果你的shell实际上运行的是sh而不是bash,或者非常旧的bash,比如默认的osx,它可能会在echo -ne "\r${BAR:0:$i}"时阻塞。准确的误差是Bad代入。如果这种情况发生在你身上,根据评论部分,你可以使用echo -ne "\r$(expr "x$name": "x.\{0,$num_skip\}\(.\{0,$num_keep\}\)")"来做一个更可移植的posix兼容/可读性较低的子字符串匹配。

一个完整的/bin/sh示例:

#!/bin/sh

src=100
tgt=0

get_work_todo() {
    echo $src
}

do_work() {
    echo "$(( $1 + 1 ))"
}

BAR_length=50
BAR_character='#'
BAR=$(printf %${BAR_length}s | tr ' ' $BAR_character)
work_todo=$(get_work_todo)             # how much there is to do
work_done=0
while true; do
    work_done="$(do_work $work_done)"
    i=$(( $work_done * $BAR_length / $work_todo ))
    n=$(( $BAR_length - $i ))
    printf "\r$(expr "x$BAR" : "x.\{0,$n\}\(.\{0,$i\}\)")"
    if [ $work_done = $work_todo ]; then
        echo "\n"
        break;
    fi
    sleep .1
done

首先将进程执行到后台,然后经常观察它的运行状态,即运行时打印模式并再次检查它的状态是否运行;

使用while循环频繁地监视进程的状态。

使用pgrep或任何其他命令来监视和获取进程的运行状态。

如果使用pgrep,则根据需要将不必要的输出重定向到/dev/null。

代码:

sleep 12&
while pgrep sleep &> /dev/null;do echo -en "#";sleep 0.5;done

此“#”将打印直到睡眠终止,此方法用于实现进度条的进度时间程序。

你也可以用这种方法来命令shell脚本,以可视化的方式分析它的进程时间。

错误: 这个pgrep方法在所有情况下都不起作用,出乎意料的是,另一个进程正在以相同的名称运行,while循环没有结束。

通过指定PID来获取进程的运行状态,使用 可能这个过程可以使用一些命令,

命令ps a将列出所有带有id的进程,您需要grep来查找指定进程的pid

在我的系统上使用pipeview (pv)实用程序的一个更简单的方法。

srcdir=$1
outfile=$2


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