shell之数值计算

1、shell 数字计算有4中方式[orac盟敢势袂le@rhel6 zxx_shell]$ cat 4-jisuan.sh#!/bi荏鱿胫协n/bashnum1=520num2=100val1=$[$num1 + $num2 ] #第一种：$[]val2=$[$num1 - $num2 ]val3=$[$num1 * $num2 ]val4=$[$num1 / $num2 ]val5=$[$num1 % $num2 ]echo "val1=$val1"echo "val2=$val2"echo "val3=$val3"echo "val4=$val4"echo "val5=$val5"a1=`expr $num1 + $num2` 第三种：` expr `echo "a1=$a1"a2=$(($num1 - $num2)) #第二种：$(())echo "a2=$a2"let a3=$num1+$num2 #第四中：let 这种方式符号和数字必须紧贴在一起echo "a3=$a3"let a4=3**3 echo "a4=$a4"[oracle@rhel6 zxx_shell]$ ./4-jisuan.shval1=620val2=420val3=52000val4=5val5=20a1=620a2=420a3=620a4=27