在小数位前面加零

Question

所以当我编码时我试图让输出打印出 0.12 而不是 0.12。下面是我的代码

echo -n "What is the total cost? ";
read cents
cost=$(echo "scale =2;$cost_in_cents/100" | bc);
percent=$(echo "scale =2;$percent / 100" | bc);
tip=$(echo "scale =2;$cost*$percent" | bc);
overall_cost=$(echo "scale =2;$cost+$tip" | bc);
average_cost=$(echo "scale =2;$overall_cost/${#GUESTS[@]}" | bc);

输出再次给出了 0.12 的正确输出，但我需要在小数点前加一个零。提前致谢！

Answer 1

value=$(printf "%3.2f\n" $(echo "scale=2; 12 / 100" | bc))

Answer 2

像这样的东西：

$ a=$(echo "0.1 + 0.1" | bc) && echo "$a"
.2
$ a=$(printf '0%s\n' "$a") && echo $a
0.2

选择：

$ echo "0.1 0.1" | awk '{printf "%.2f\n", $1 + $2}'
0.20

Answer 3

Bash 有 printf。您可以执行类似printf '%.2f' $cents打印四舍五入到小数点后两位的操作。如果想将其赋值给变量，则使用-v或使用$()结构体。