将 for 循环结果存储为 bash 中的变量
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Store for loop results as a variable in bash
提问by Tony
I have a loop similar to the following:
我有一个类似于以下的循环：
for time in ${seconds_list}; do
echo "scale=2; (${cur_time}-${time})/3600" | bc
done
Of course, I could "echo" the results to a file and be done with it, but I think a more elegant approach would be to store all the for-loop results in one variable, that I could use at a later time. The variable containing all results would have to look something like this:
当然，我可以将结果“回显”到一个文件中并完成它，但我认为更优雅的方法是将所有 for 循环结果存储在一个变量中，我可以在以后使用。包含所有结果的变量必须如下所示：
var='30.25
16.15
64.40
29.80'
Is there an easy way in which I can achieve this?
有没有一种简单的方法可以实现这一目标？
回答by Stefano d'Antonio
It's really easy, you can just redirect the output of the whole loop to a variable (if you want to use just one variable as stated):
这真的很简单，您只需将整个循环的输出重定向到一个变量（如果您只想使用一个变量）：
VARIABLE=$(for time in ...; do ...; done)
your example:
你的例子：
var=$(for time in ${seconds_list}; do
echo "scale=2; (${cur_time}-${time})/3600" | bc
done)
Just enclosing your code into $().
只需将您的代码包含在 $() 中。
回答by anubhava
Better to use a BASH array to store your results:
最好使用 BASH 数组来存储您的结果：
results=()
for time in ${seconds_list}; do
results+=($(bc -l <<< "scale=2; ($cur_time-$time)/3600"))
done
# print the results:
printf "%s\n" "${results[@]}"
