Using the shell to complete the size comparison of two numbers

Brief description:

Prompts the user to enter two numbers;

Determine whether the input content is a number;

Numbers do calculations and feedback results;

When the calculation is complete, ask the customer whether to continue using;

Provides a way for users to exit at any time.

[email protected] scripts]# cat jisuan2.sh

#!/bin/bash

# # #thank_oldboy

# # #2016/3/6

# # #i wish the best.

. /etc/init.d/functions

# # Read number.

function Read_number() {

Read-p "Please enter the Number1:" Num1

Read-p "Please enter the number2:" num2

Panduan_number

}

# # # Judge $number 1 $number 2 both is number.

function Panduan_number() {

Expr $num 1 + $num 2 &>/dev/null

[$?-ne 0] && {

[[$num 1 = = Exit | | $num 2 = exit]] && {

echo "You had choice Leave,bye."

Exit 0

} || {

echo "Usage:you must enter the numbers, or enter exit to leave."

Read_number

}

} || Judge_number

}

# # # Judge continue or exit.

function continue_or_exit() {

Read-p "Please enter the go to continue or enter off to leave:" Str

Case ' $str ' in

Go

Read_number

;;

Out

echo "Hope to see you again,bye."

Exit 0

;;

*)

echo "Usage:enter Go or Out:"

Continue_or_exit

;;

Esac

}

# # # expr $number 1 $number 2.

function Judge_number() {

[$num 1-eq $num 2] && {

echo "$num 1 equal $num 2."

Continue_or_exit

}

[$num 1-gt $num 2] && {

echo "$num 1 greater than $num 2."

Continue_or_exit

}

[$num 1-lt $num 2] && {

echo "$num 1 lower than $num 2."

Continue_or_exit

}

}

# # # The Gate of the script.

function main() {

Read_number

}

Main

Using the shell to complete the size comparison of two numbers