读取数字，然后将它们添加到循环中。Bash/Linux
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Reading in numbers, then adding them in a loop. Bash/Linux
提问by John Doe
Help!
帮助！
I am having big problems finding out how to add numbers that i've written in(read) a loop. The task im supposed to do is to add X amount of numbers(which I must use read for) then adding them all when "Ctrl+d" is pressed. Im fairly new to linux so please make it as simple as possible :)
我在找出如何添加我在（读取）循环中写入的数字时遇到了大问题。我应该做的任务是添加 X 数量的数字（我必须使用 read ），然后在按下“Ctrl + d”时将它们全部添加。我对 linux 还很陌生，所以请尽可能简单:)
回答by lulyon
#!/bin/bash
sum=0
while read num;
do
let sum=sum+num;
done
echo $sum
Command：
命令：
./script.sh
Input:
输入：
1
2
3
4
5
ctrl+D
Output:
输出：
15
回答by sehe
My favorite trick here employs bc:
我最喜欢的技巧是bc：
xargs -n1 | paste -sd+ | bc
Though you could use bash evaluation if you don't want to use bc:
虽然如果您不想使用，您可以使用 bash 评估bc：
sum=$(($(xargs -n1 | paste -sd+)))
echo $sum
回答by konsolebox
#!/bin/bash
shopt -s extglob
SUM=0
while read NUM && [[ $NUM == +([[:digit:]]) ]]; do
(( SUM += NUM ))
done
echo "$SUM"
回答by Bluewind
Assuming your input contains one number per line and nothing else, something like this should work:
假设您的输入每行包含一个数字，没有其他内容，这样的事情应该可以工作：
cat $file | tr "\n" "+" | tr -d " " | sed 's/\+$/\n/' | bc
(Useless use of cat: This is a example and therefore cat $file represents anything that might output one number per line)
（cat 的无用使用：这是一个例子，因此 cat $file 代表任何可能每行输出一个数字的东西）
If your numbers aren't integers, you can add the -l option to bc which will enable among other things floating point support.
如果您的数字不是整数，您可以将 -l 选项添加到 bc，这将启用浮点支持等。
