Array in Shell Script

Shell script is powerful if you could remember all the weird syntax. Here is the example to show how to use Array in Shell script. Note: readarray only works in Bash 4.x, check your version: bash --version

    string='Paris, France, Europe';
    echo $string
    readarray -td, array <<<"$string"; declare -p array;
    ## declare -a array=([0]="Paris" [1]=" France" [2]=$' Europe\n')

    country='Paris/Frence/Europe/Sweden/Croatia';
    echo $country
    readarray -td/ array <<<"$country"; declare -p array;
    for item in "${array[@]}" 
    do
        echo "$item" 
    done

Shell Script loop

    for i in *; do
        echo $i
    done

    for i in *; do echo $i ; done

    # copy all file name with pattern debug to $w/zsurface/image
    for i in $(ls | grep html | awk '{print $1}'); do cp $w/zsurface/image; done

    # print file name in ls -lah
    awk '{print $9}'

gsed, sed replace text in many files

    # replace oldstring with newstring for all html file 
    # and backup all the files with suffix _backup
    gsed -i_backup 's/oldstring/newstring/' *.html

Compare Number in Fish Shell

    if math "$SHLVL == 1"
        read -p 'echo "Exit? (y/n):"' -l confirm
        if [ $confirm = "y" ]
            exit
        end
    else if math "$SHLVL > 1"
        exit
    end

Customize Prompt in Fish Shell

    function fish_prompt
        set_color green 
        echo -n (pwd)"[$SHLVL]"'>'
    end

Compare String in Fish Shell

    if [ $confirm = "y" ]
        exit
    end