DEMO:

[xiluhua@vm-xiluhua][~]$ num1=5 [xiluhua@vm-xiluhua][~]$ num2=10 [xiluhua@vm-xiluhua][~]$ num3=$(($num1+$num2))　　#嵌套变量加法运算并赋值 [xiluhua@vm-xiluhua][~]$ echo $num315 [xiluhua@vm-xiluhua][~]$ num4=$(($num2%3))　　　　#嵌套变量取余运算并赋值 [xiluhua@vm-xiluhua][~]$ echo $num41 [xiluhua@vm-xiluhua][~]$ echo $(( 5 > 10 ))　　#比较运算，假返回00 [xiluhua@vm-xiluhua][~]$ echo $(( $num2 > $num1 ))　　#比较运算，真返回11 [xiluhua@vm-xiluhua][~]$ num5=$(( $(($num1>$num2))?$num1:$num2 ))　　#三目运算符举例[xiluhua@vm-xiluhua][~]$ echo $num510