Linux学习4之shell脚本中的小数运算

1.awk

hadoop@Mcnode1:~/cloud/adam/xubo/data/test20160310/test$ cat demical.sh 
#!/bin/bash
echo `awk -v x=2.45 -v y=3.123 'BEGIN{printf "%.2f\n",x*y}'`
s=1.5
echo $s
echo `awk -v x=2.45 -v y="$s" 'BEGIN{printf "%.2f\n",x*y}'`

结果：

hadoop@Mcnode1:~/cloud/adam/xubo/data/test20160310/test$ ./demical.sh 
7.65
1.5
3.68

可以从外部获取变量，也可以自定义变量

2.|bc

hadoop@Mcnode1:~/cloud/adam/xubo/data/test20160310/test$ cat demical.sh 
#!/bin/bash
echo `awk -v x=2.45 -v y=3.123 'BEGIN{printf "%.2f\n",x*y}'`
s=1.5
echo $s
echo `awk -v x=2.45 -v y="$s" 'BEGIN{printf "%.2f\n",x*y}'`
#product=`awk -v x=2.45 -v y="$s" 'BEGIN{printf "%.2f\n",x*y}'`

s2=$(echo "scale=3; 6 / 5"  | bc)
echo $s2

s3=$(echo "scale=3; $s / 5"  | bc)
echo $s3

结果：

hadoop@Mcnode1:~/cloud/adam/xubo/data/test20160310/test$ ./demical.sh 
7.65
1.5
3.68
1.200
.300