Shell脚本实现的猜数字小游戏

#!/bin/bash
clear
echo
echo "###################################################################"
echo "# this is a bash-shell game write by Email:breeze7086@gmail.com #"
echo "# the game called *digits*,and this version have repeated numbers #"
echo "#              version 1.0              #"
echo "###################################################################"
echo -e "\n\n"
declare INPUT
declare PASSWORD
declare A
declare B
declare X
declare Y
declare LOOP
#This funtion init the variable PASSWORD that user need to guess
init_password()
{
    PASSWORD=`echo $(($RANDOM%10000))`
    echo $PASSWORD | grep '^[0-9]\{4\}$' >/dev/null 2>&1
    if [ $? != 0 ]
    then
        init_password
    else
        input
    fi
}
#This funtion accept the input from user's keyboard
input()
{
    echo -n "please input a number between 0000-9999:"
    read INPUT
    echo $INPUT | grep '^[0-9]\{4\}$' >/dev/null 2>&1
    if [ $? != 0 ]
    then
        echo "retry a number between 0000-9999 and do not input a char"
        input
    else
        judge
    fi
}
#This funtion is the main funtion
judge()
{
    X=$INPUT
    Y=$PASSWORD
    while [ $INPUT != $PASSWORD ]
    do
        A=0
        B=0
        judge_a
        judge_b
        LOOP=`expr $LOOP + 1`
        echo "****************************"
        echo "*      "$A"A"$B"B      *"
        echo "****************************"
        input
    done
}
#This funtion count the variable A's value
judge_a()
{
        for i in `seq 4`
        do
            VAR_INPUT=`expr substr "$X" $i 1`
            for j in `seq 4`
            do
                VAR_PASSWORD=`expr substr "$Y" $j 1`
                if [[ $VAR_INPUT = $VAR_PASSWORD && $VAR_INPUT != "" && $VAR_PASSWORD != "" && $i = $j ]]
                then
                    A=`expr $A + 1`
                    X=`expr substr $X 1 "$[$i-1]"``expr substr $X "$[$i+1]" 4`
                    Y=`expr substr $Y 1 "$[$i-1]"``expr substr $Y "$[$i+1]" 4`
                    judge_a
                fi
            done
        done
}
#This funtion count the variable B's value
judge_b()
{
        for i in `seq 4`
        do
            VAR_INPUT=`expr substr "$X" $i 1`
            for j in `seq 4`
            do
                VAR_PASSWORD=`expr substr "$Y" $j 1`
                if [[ $VAR_INPUT = $VAR_PASSWORD && $VAR_INPUT != "" && $VAR_PASSWORD != "" ]]
                then
                    B=`expr $B + 1`
                    X=`expr substr "$X" 1 "$[$i-1]"``expr substr "$X" "$[$i+1]" 4`
                    Y=`expr substr "$Y" 1 "$[$j-1]"``expr substr "$Y" "$[$j+1]" 4`
                    judge_b
                fi
            done
        done
}
#This is the begin of script
LOOP=1
init_password
echo "#############################################"
echo "#congratulations!You have tried $LOOP times!  #"
echo "#    The password is $PASSWORD !       #"
echo "#############################################"