Tic-Tac-Toe in bash

minmax.sh

#!/bin/bash
# Nicolas Mauger, ESD17

# SHALL WE PLAY A GAME ?

PLUS_INFINITY=65536
MINUS_INFINITY=-65536

tab=( 0 0 0 0 0 0 0 0 0 )

display() {
    
    local x=()
    for((i=0; i < 9; i++)){
        case ${tab[i]} in
            1)
                x+=( "X" )
                ;;
            2)
                x+=( "O" )
                ;;
            *)
                x+=( " " )
        esac
    }

    echo "
    ${x[0]} | ${x[1]} | ${x[2]}
    ---------
    ${x[3]} | ${x[4]} | ${x[5]}
    ---------
    ${x[6]} | ${x[7]} | ${x[8]}
    "

}

minmax(){
    count_free_space=0
    for i in "${tab[@]}"; do
        if [ $i -eq 0 ]; then
            (( count_free_space++ ))        
        fi
    done
    
    # Choosing a random start position
    if [ $count_free_space -eq 9 ]; then
        best_move=$(( RANDOM % 8 ))
    else
        max
    fi  
}

min () {
    tempCheck=$(is_game_finish)
    if [[ $tempCheck -ne 0 ]]; then
        if [[ $tempCheck -eq 2 ]]; then
            scoreMinMax=$PLUS_INFINITY
        elif [[ $tempCheck -eq 1 ]]; then
            scoreMinMax=$MINUS_INFINITY
        else 
            scoreMinMax=0
        fi
    else
        local empty_space=()
        indexCase=0
        for i in "${tab[@]}"; do
            if [ $i -eq 0 ]; then
                empty_space+=($indexCase)
            fi
            (( indexCase++ ))
        done
        
        local bestTemp=-1
        local scoreTemp=$PLUS_INFINITY
        
        for i in "${empty_space[@]}"; do
            tab[$i]=1
            local stockItemp=$i
            max
            i=$stockItemp
            tab[$i]=0
            if [[ $scoreTemp -gt $scoreMinMax ]]; then
                local scoreTemp=$scoreMinMax
                local bestTemp=$i
                if [[ $scoreTemp -eq $MINUS_INFINITY ]]; then
                    break
                fi
            fi
        done
        scoreMinMax=$scoreTemp
        best_move=$bestTemp
    fi
}

max (){
    tempCheck=$(is_game_finish)
    if [[ $tempCheck -ne 0 ]]; then
        if [[ $tempCheck -eq 2 ]]; then
            scoreMinMax=$PLUS_INFINITY
        elif [[ $tempCheck -eq 1 ]]; then
            scoreMinMax=$MINUS_INFINITY
        else 
            scoreMinMax=0
        fi
    else
        local empty_space=()
        indexCase=0
        for i in "${tab[@]}"; do
            if [ $i -eq 0 ]; then
                empty_space+=($indexCase)
            fi
            (( indexCase++ ))
        done
        
        local bestTemp=-1
        local scoreTemp=$MINUS_INFINITY
        
        for i in "${empty_space[@]}"; do
            tab[$i]=2
            local stockItemp=$i
            min
            i=$stockItemp
            tab[$i]=0
            if [[ $scoreTemp -lt $scoreMinMax ]]; then
                local scoreTemp=$scoreMinMax
                local bestTemp=$i
                if [[ $scoreTemp -eq $PLUS_INFINITY ]]; then
                    break
                fi
            fi
        done
        scoreMinMax=$scoreTemp
        best_move=$bestTemp
    fi
}


is_game_finish () {

    # Line
    if   [[ ${tab[0]} == ${tab[1]} ]] && [[ ${tab[1]} == ${tab[2]} ]] && [[ ${tab[0]} !=  " " ]]; then
        echo "${tab[0]}"
    elif [[ ${tab[3]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[5]} ]] && [[ ${tab[3]} !=  " " ]]; then
        echo "${tab[3]}"
    elif [[ ${tab[6]} == ${tab[7]} ]] && [[ ${tab[7]} == ${tab[8]} ]] && [[ ${tab[6]} !=  " " ]]; then
        echo "${tab[6]}"

        # Col
    elif [[ ${tab[0]} == ${tab[3]} ]] && [[ ${tab[3]} == ${tab[6]} ]] && [[ ${tab[0]} !=  " " ]]; then
        echo "${tab[0]}"
    elif [[ ${tab[1]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[7]} ]] && [[ ${tab[1]} !=  " " ]]; then
        echo "${tab[1]}"
    elif [[ ${tab[2]} == ${tab[5]} ]] && [[ ${tab[5]} == ${tab[8]} ]] && [[ ${tab[2]} !=  " " ]]; then
        echo "${tab[2]}"

        # Diagonal
    elif [[ ${tab[0]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[8]} ]] && [[ ${tab[0]} !=  " " ]]; then
        echo "${tab[0]}"
    elif [[ ${tab[2]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[6]} ]] && [[ ${tab[2]} !=  " " ]]; then
        echo "${tab[2]}"
    else
        j=5
        for((i=0; i < 9; i++)){
            if [ ${tab[i]=0} -eq 0 ]
            then
                j=0
                break
            fi
        }
        echo $j
    fi
}

ask (){
    echo "Enter a value between 0 and 8 which is in a free space :"
    read -r coord
    if ! [[ "$coord" =~ ^[0-8]$ ]]; then
        echo -n "Not a correct value! "
        ask
    elif [ ${tab[$coord]} -eq 0 ]; then
        tab[$coord]=$player
    else
        echo "This position is already taken! "
        ask
    fi
}

# Tic-tac-toe game VS minmax AI.
main () {
    
    player=1

    display
    while [[ $(is_game_finish) = 0 ]]; do
        if [ "$player" -eq 1 ]; then
            ask
        else
            echo -n "Compute IA turn ... (please take a coffe)"
            minmax
            echo " Done.";
            tab[$best_move]=2
        fi
        display
        [ $player -eq 1 ] && player=2 || player=1
    done

    [ $player -eq 1 ] && player=2 || player=1
    if [ $(is_game_finish) -eq 2 ]; then
        echo "Skynet win. Fatality."
    elif [ $(is_game_finish) -eq 1 ]; then
        echo "Congratulation you won the game!" # theoricaly this line will never appear
    else
        echo "It's a draw, no winner !"
    fi

}

main && exit 0

# GREETINGS PROFESSOR
#
# A STANGE GAME.
# THE ONLY WINNING MOVE IS NOT TO PLAY.
#
# HOW ABOUT A NICE GAME OF CHESS?

pvp.sh

#!/bin/bash
# Nicolas Mauger, ESD17
# Here I release the future Skynet

tab=( " " " " " " " " " " " " " " " " " " )
IS_GAME_FINISH=false

display () {
	echo "
	${tab[0]} | ${tab[1]} | ${tab[2]}
	---------
	${tab[3]} | ${tab[4]} | ${tab[5]}
	---------
	${tab[6]} | ${tab[7]} | ${tab[8]}
	"
}

ask () {
	echo "Enter a value between 0 and 8 which is in a free space :"
	read -r coord
	if ! [[ "$coord" =~ ^[0-8]$ ]]; then
        echo -n "Not a correct value! "
        ask "$1"
    elif ! [[ ${tab[$coord]} == " " ]]; then
       echo -n "This position is already taken! "
       ask "$1"
    else
    	tab[$coord]=$1
    fi
}

is_game_finish () {
	# Line
	if   [[ ${tab[0]} == ${tab[1]} ]] && [[ ${tab[1]} == ${tab[2]} ]] && [[ ${tab[0]} !=  " " ]]; then
		IS_GAME_FINISH=true
	elif [[ ${tab[3]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[5]} ]] && [[ ${tab[3]} !=  " " ]]; then
		IS_GAME_FINISH=true
	elif [[ ${tab[6]} == ${tab[7]} ]] && [[ ${tab[7]} == ${tab[8]} ]] && [[ ${tab[6]} !=  " " ]]; then 
		IS_GAME_FINISH=true
		# Col
	elif [[ ${tab[0]} == ${tab[3]} ]] && [[ ${tab[3]} == ${tab[6]} ]] && [[ ${tab[0]} !=  " " ]]; then
		IS_GAME_FINISH=true
	elif [[ ${tab[1]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[7]} ]] && [[ ${tab[1]} !=  " " ]]; then
		IS_GAME_FINISH=true
	elif [[ ${tab[2]} == ${tab[5]} ]] && [[ ${tab[5]} == ${tab[8]} ]] && [[ ${tab[2]} !=  " " ]]; then
		IS_GAME_FINISH=true
		# Diagonal
	elif [[ ${tab[0]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[8]} ]] && [[ ${tab[0]} !=  " " ]]; then
		IS_GAME_FINISH=true
	elif [[ ${tab[2]} == ${tab[4]} ]] && [[ ${tab[4]} == ${tab[6]} ]] && [[ ${tab[2]} !=  " " ]]; then
		IS_GAME_FINISH=true
	else
		IS_GAME_FINISH=false
	fi
}

main () {
	player1="X"
	player2="O"
	player="$player1"
	COUNTER=0

	while ! $IS_GAME_FINISH; do
		(( COUNTER++ ))
		[ $COUNTER -ge 9 ] && echo "It's a draw, no winner !" && exit 0 
		[[ "$player" == "$player2" ]] && player="$player1" || player="$player2"
		echo "Player $player, it's your turn." && display
		ask $player
		is_game_finish 
	done
	display && echo "Congratulation to player $player who won the game!"
}

main && exit 0