shell的算术运算总结

不多说，上代码。

#!/bin/bash                                                                                                                          a=1b=2c=3d=4array1[0]=`expr $a + $b`#array1[1]=`expr $a+$b`     # this should be echo "1+2"array1[1]=`expr $d \* $c`echo ${array1[@]}   # 3 12 array2[0]=$(($a+$b))array2[1]=$(($b*$c))array2[2]=$(($b**$c))array2[3]=$((($b+$c)*$c))echo ${array2[@]}   # 3 6 8 15array3=()array3[0]=`echo "$b*$c" | bc`array3[1]=`echo "$b^$c" | bc`array3[2]=`echo "$d/$c" | bc`array3[3]=`echo "scale=2;$d/$c" | bc`    # scale的数值用来控制小数后显示的位数echo ${array3[@]}    # 6 8 1 1.33