TicTacToe Bash script

Question

I can't select the last square (3;3). The main problem was that. I hope someone can help me because i cannot know whats the problem.

The code is here:

#!/bin/bash

board=( " "  " "  " "
        " "  " "  " "
        " "  " " )

function draw_board {
    echo "+---+---+---+"
    echo "| ${board[0]} | ${board[1]} | ${board[2]} |"
    echo "+---+---+---+"
    echo "| ${board[3]} | ${board[4]} | ${board[5]} |"
    echo "+---+---+---+"
    echo "| ${board[6]} | ${board[7]} | ${board[8]}  |"
    echo "+---+---+---+"
}

function check_win {
    local symbol=$1
    if [[ ${board[0]} == $symbol && ${board[1]} == $symbol && ${board[2]} == $symbol ]] ||
       [[ ${board[3]} == $symbol && ${board[4]} == $symbol && ${board[5]} == $symbol ]] ||
       [[ ${board[6]} == $symbol && ${board[7]} == $symbol && ${board[8]} == $symbol ]] ||
       [[ ${board[0]} == $symbol && ${board[3]} == $symbol && ${board[6]} == $symbol ]] ||
       [[ ${board[1]} == $symbol && ${board[4]} == $symbol && ${board[7]} == $symbol ]] ||
       [[ ${board[2]} == $symbol && ${board[5]} == $symbol && ${board[8]} == $symbol ]] ||
       [[ ${board[0]} == $symbol && ${board[4]} == $symbol && ${board[8]} == $symbol ]] ||
       [[ ${board[2]} == $symbol && ${board[4]} == $symbol && ${board[6]} == $symbol ]]; then
        echo true
    else
        echo false
    fi
}


function is_free {
    local index=$1
    if [[ ${board[$index]} == " " ]]; then
        echo true
    else
        echo false
    fi
}

function game_loop {
    local player="X"
    local move_count=0
    local win=false
    while [[ $move_count -lt 10  && $win == false ]]; do
        draw_board
        echo "$player következik. Adja meg az x koordinátát [1-3]: "
        read x
        echo "Adja meg az y koordinátát [1-3]: "
        read y
        x=$((x-1))
        y=$((y-1))
        if [[ $x -lt 0 || $x -gt 2 || $y -lt 0 || $y -gt 2 ]]; then
            echo "Hibás koordináta!" >&2
        elif [[ $(is_free $((y*3+x))) == true ]]; then
            board[$((y*3+x))]="$player"
            win=$(check_win $player)
            if [[ $win == true ]]; then
                echo "$player győzött!"
            else
                ((move_count++))
                if [[ $player == "X" ]]; then
                    player="O"
                else
                    player="X"
        fi
        echo "Lépéshiba!" >&2
        fi
        fi
    done
if [[ $win == false ]]; then
    draw_board
    echo "Dontetlen!"
fi
}

I tried 3;3 and the program was not accept it and give me another try. Thank you for the reading! If you have any solution please share with me! Have a nice day!

Answer 1

Your original script was a nice piece of work for a terminal game. However...

There was some logic error in the calculation of the placement positions in the grid.

Also, I shifted the bash array by one ... in order to make the 3x3 matrix more consistent with traditional mathematical representations of coordinates.

In the below adaptation of the script, I have also updated the message strings with some sensible equivalents in English for common understanding.

I am personally not a fan of elif usage, so I exploded those code segments for more clarity (in my view). I hope you like the updated version.

The modified script:

#!/bin/bash

board=( " "
    " "  " "  " "
    " "  " "  " "
    " "  " "  " " )

function draw_board {
    echo -e "\n\t+---+---+---+"
    echo -e "\t| ${board[1]} | ${board[2]} | ${board[3]} |"
    echo -e "\t+---+---+---+"
    echo -e "\t| ${board[4]} | ${board[5]} | ${board[6]} |"
    echo -e "\t+---+---+---+"
    echo -e "\t| ${board[7]} | ${board[8]} | ${board[9]} |"
    echo -e "\t+---+---+---+"
}

function check_win {
    local symbol=${1}
    if [[ ${board[1]} == ${symbol} && ${board[2]} == ${symbol} && ${board[3]} == ${symbol} ]] ||
       [[ ${board[4]} == ${symbol} && ${board[5]} == ${symbol} && ${board[6]} == ${symbol} ]] ||
       [[ ${board[7]} == ${symbol} && ${board[8]} == ${symbol} && ${board[9]} == ${symbol} ]] ||
       [[ ${board[1]} == ${symbol} && ${board[4]} == ${symbol} && ${board[7]} == ${symbol} ]] ||
       [[ ${board[2]} == ${symbol} && ${board[5]} == ${symbol} && ${board[8]} == ${symbol} ]] ||
       [[ ${board[3]} == ${symbol} && ${board[6]} == ${symbol} && ${board[9]} == ${symbol} ]] ||
       [[ ${board[1]} == ${symbol} && ${board[5]} == ${symbol} && ${board[9]} == ${symbol} ]] ||
       [[ ${board[3]} == ${symbol} && ${board[5]} == ${symbol} && ${board[7]} == ${symbol} ]]; then
        echo "true"
    else
        echo "false"
    fi
}


function is_free {
    local index=${1}
    if [[ ${board[${index}]} == " " ]]; then
        echo "true"
    else
        echo "false"
    fi
}

function game_loop {
    local player="X"
    local move_count=0
    local win=false

    draw_board

    while [[ ${move_count} -lt 9 ]]; do
        #echo "$player következik. Adja meg az x koordinátát [1-3]: "
        echo -e "\nPlayer $player:\n\tEnter your choice of x coordinate [1-3]: \c"
        read x
        echo -e "\tEnter your choice of y coordinate [1-3]: \c"
        read y

        if [[ $x -lt 1 || $x -gt 3 || $y -lt 1 || $y -gt 3 ]]; then
            echo -e "\tInvalid coordinate entered!" >&2
    else
        if [[ $(is_free $(( (y-1) * 3 + x ))) == true ]]; then
            board[$(( (y-1) * 3 + x ))]="${player}"
                ((move_count++))

                win=$(check_win $player)
                if [[ ${win} == "true" ]]; then
                    draw_board
                    echo -e "\n\t*** ${player} wins Tic-Tac-Toe ***"
                    break
                else
                    if [[ ${player} == "X" ]]; then
                            player="O"
                    else
                            player="X"
                fi
            fi
        else
            echo -e "\t\t That space is taken.  Please choose another ..."
            fi
        fi
        draw_board
    done

    if [[ ${win} == "false" ]]; then
        echo -e "\n\t*** Draw ***"
    fi
}

game_loop