如何用一个简单的命令将大量变量附加到一个变量上 [英] How to append lots of variables to one variable with a simple command

问题描述

我想将所有变量都放在一个变量中

I want to stick all the variables into one variable

A=('blah')
AA=('blah2')
AAA=('blah3')
AAB=('blah4')
AAC=('blah5')
#^^lets pretend theres 100 more of these ^^
#Variable composition
#after AAA, is AAB then AAC then AAD etc etc, does that 100 times

我希望将它们全部放入此MASTER变量

I want them all placed into this MASTER variable

#MASTER=${A}${AA}${AAA} (<-- insert AAB, AAC and 100 more variables here)

我显然不想在此表达式中键入100个变量，因为可能有一种更简单的方法来执行此操作.另外，我将做更多的事情，因此我需要自动化.

I obviously don't want to type 100 variables in this expression because there's probably an easier way to do this. Plus I'm gonna be doing more of these therefore I need it automated.

我对sed比较陌生，awk，有没有办法将这100个变量附加到主变量中?

I'm relatively new to sed, awk, is there a way to append those 100 variables into the master variable?

为此，我不需要数组.

推荐答案

您可以使用简单单线，虽然很昂贵，但很简单:

You can use a simple one-liner, quite straightforward, though more expensive:

master=$(set | grep -E '^(A|AA|A[A-D][A-D])=' | sort | cut -f2- -d= | tr -d '\n')

• set列出所有var=name格式的变量
• grep过滤掉我们需要的变量
• sort按正确的顺序放置它们(由于set提供排序的输出，因此可能是可选的)
• cut提取值，删除变量名
• tr删除换行符
• set lists all the variables in var=name format
• grep filters out the variables we need
• sort puts them in the right order (probably optional since set gives a sorted output)
• cut extracts the values, removing the variable names
• tr removes the newlines

让我们测试一下.

A=1
AA=2
AAA=3
AAB=4
AAC=5
AAD=6
AAAA=99 # just to make sure we don't pick this one up
master=$(set | grep -E '^(A|AA|A[A-D][A-D])=' | sort | cut -f2- -d= | tr -d '\n')
echo "$master"

输出:

123456

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