SED - 通匹配外部命令 [英] sed - pass match to external command

问题描述

我一直在使用sed来改造这个写了一个小脚本：

I have written a little script using sed to transform this:

kaefert@Ultrablech ~ $ cat /sys/class/power_supply/BAT0/uevent
POWER_SUPPLY_NAME=BAT0
POWER_SUPPLY_STATUS=Full
POWER_SUPPLY_PRESENT=1
POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CYCLE_COUNT=0
POWER_SUPPLY_VOLTAGE_MIN_DESIGN=7400000
POWER_SUPPLY_VOLTAGE_NOW=8370000
POWER_SUPPLY_POWER_NOW=0
POWER_SUPPLY_ENERGY_FULL_DESIGN=45640000
POWER_SUPPLY_ENERGY_FULL=44541000
POWER_SUPPLY_ENERGY_NOW=44541000
POWER_SUPPLY_MODEL_NAME=UX32-65
POWER_SUPPLY_MANUFACTURER=ASUSTeK
POWER_SUPPLY_SERIAL_NUMBER= 

到这样一个CSV文件格式：

into a csv file format like this:

kaefert@Ultrablech ~ $ Documents/Asus\ Zenbook\ UX32VD/power_to_csv.sh 
"date";"status";"voltage µV";"power µW";"energy full µWh";"energy now µWh"
2012-07-30 11:29:01;"Full";8369000;0;44541000;44541000 
2012-07-30 11:29:02;"Full";8369000;0;44541000;44541000 
2012-07-30 11:29:04;"Full";8369000;0;44541000;44541000
... (in a loop)

我现在想是1.000.000每个这些数字的划分，让他们不要再presentμV，但V和W代替μW，让他们在轻松间preTABLE快速浏览。当然，我能做到这一点之后手动一旦我开了自由报办公室计算这里面的CSV，但我想它使自动化

What I would like now is to divide each of those numbers by 1.000.000 so that they don't represent µV but V and W instead of µW, so that they are easily interpretable on a quick glance. Of course I could do this manually afterwards once I've opened this csv inside libre office calc, but I would like to automatize it.

所以，我发现的是，我可以调用在sed之间的外部程序，例如：

So what I found is, that I can call external programs in between sed, like this:

...
s/\nPOWER_SUPPLY_PRESENT=1\nPOWER_SUPPLY_TECHNOLOGY=Li-ion\nPOWER_SUPPLY_CYCLE_COUNT=0\nPOWER_SUPPLY_VOLTAGE_MIN_DESIGN=7400000\nPOWER_SUPPLY_VOLTAGE_NOW=\([0-9]\{1,\}\)/";'`echo 0`'\1/

和像我想通过这样的事情，我能得到的值：

and that I could get values like I want by something like this:

echo "scale=6;3094030/1000000" | bc | sed 's/0\{1,\}$//'

但现在的问题是，我该如何通过我的比赛\\ 1到外部命令？

But the problem now is, how do I pass my match "\1" into the external command?

如果您有兴趣看完整剧本，你会在那里找到它：
http://koega.no-ip.org/mediawiki/index.php/Battery_info_to_csv

If you are interested in looking at the full script, you'll find it there: http://koega.no-ip.org/mediawiki/index.php/Battery_info_to_csv

推荐答案

如果你的sed是GNU sed的。你可以用E来匹配的组/ sed的命令中传递到外部命令的工具。

if your sed is GNU sed. you can use 'e' to pass matched group to external command/tools within sed command.

一个例子可能有助于更清晰：

an example might be helpful to make it clear:

比如说，你有一个问题：结果
你有120 + 20foobar现在你要得到120 + 20部分的计算结果的字符串，并取代面向对象到foobar的一部分XX 。

say, you have a problem:
you have a string "120+20foobar" now you want to get the calculation result of 120+20 part, and replace "oo" to "xx" in "foobar" part.

请注意，这个例子是不是解决上述的问题，只是为
  显示了sed的'E'使用

Note that this example is not for solving the problem above, just for showing the sed 'e' usage

所以你可以让 120 + 20 第一场比赛组，其余的在第二组中，然后通过两组不同的命令/工具，然后得到的结果。这样的：

so you could make 120+20 in the first match group, and rest in 2nd group, then pass two groups to different command/tools and then get the result. like:

   kent$  echo "100+20foobar"|sed -r 's#([0-9+]*)(.*)#echo  \1 \|bc\;echo \2 \| sed "s/oo/xx/g"#ge'
    120
    fxxbar

在这种方式，你可以窝很多SEDS之一，一个又一个，直到你迷路。 ：D

in this way, you could nest many seds one in another one, till you get lost. :D

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