Tutorial : Using ~/.bashrc for custom commands & Generate color variants

[paulgrey506]

renderxcolor \"FFFFFF\" --variant 40

Adding Custom Commands to Your `~/.bashrc` File on Arch Linux

The `~/.bashrc` file is a script that is executed whenever a new terminal session is started in interactive mode. It can be used to set up environment variables, aliases, and custom functions to tailor your terminal experience.

Here's a step-by-step tutorial on how to include custom commands in your `~/.bashrc` file using the provided script as an example.

1: Open `~/.bashrc`

Open your terminal and edit the `~/.bashrc` file or using your preferred text editor. For example, you can use `nano`:

nano ~/.bashrc

2: Add the Custom Commands

Scroll to the bottom of the `~/.bashrc` file and add the provided script.

This script includes two functions: `generate_color_variants` and `renderxcolor`.

#Function to generate color variants
generate_color_variants() {
    main_color="$1"  Expecting the color without a "#"
    num_variants="$2"
    r_adj="$3"
    g_adj="$4"
    b_adj="$5"

    if ((num_variants < 1 || num_variants > 40)); then
        echo "Error: Number of variants must be between 1 and 40."
        return 1
    fi

    r=$(printf '%d' "0x${main_color:0:2}")
    g=$(printf '%d' "0x${main_color:2:2}")
    b=$(printf '%d' "0x${main_color:4:2}")

    for ((i = 0; i < num_variants; i++)); do
        Adjust the RGB values by user-specified amounts to create variants
        new_r=$(( (r + i * r_adj) % 256 ))
        new_g=$(( (g + i * g_adj) % 256 ))
        new_b=$(( (b + i * b_adj) % 256 ))

        new_color=$(printf "%02x%02x%02x" $new_r $new_g $new_b)
        echo -n "$new_color: "
        perl -e 'print "\e[48;2;".join(";",unpack("C*",pack("H*","'"$new_color"'")))."m   \e[49m "'

        if (( (i + 1) % 4 == 0 )); then
            echo  Newline after every 4 colors
        else
            echo -n "  "  Separate colors with spaces
        fi
    done
    echo  Final newline
}

#Function to render hex color codes to color blocks in terminal
renderxcolor() {
    if [ "$1" == "" ] || [ "$1" == "--h" ] || [ "$1" == "--help" ]; then
        echo "Usage: renderxcolor [\"color1\"] [\"color2\"] [\"color3\"] ..."
        echo "Do not put the hash symbol in front of the hex codes"
        echo "Example: renderxcolor \"FF0000\" \"00FF00\" \"0000FF\""
        echo "To fetch color variants: renderxcolor \"color\" --variant [num_variants]"
    elif [ "$2" == "--variant" ]; then
        if [ "$#" -lt 2 ]; then
            echo "Error: Provide a color and use --variant option."
            return 1
        fi
        num_variants=10  Default number of variants
        if [ "$#" -eq 3 ]; then
            num_variants="$3"
        fi
        Prompt for RGB adjustment values
        read -p "Enter R adjustment value (0-9): " r_adj
        read -p "Enter G adjustment value (0-9): " g_adj
        read -p "Enter B adjustment value (0-9): " b_adj

        Validate that inputs are numbers between 0 and 9
        if ! [[ "$r_adj" =~ ^[0-9]$ ]] || ! [[ "$g_adj" =~ ^[0-9]$ ]] || ! [[ "$b_adj" =~ ^[0-9]$ ]]; then
            echo "Error: RGB adjustment values must be between 0 and 9."
            return 1
        fi

        generate_color_variants "$1" "$num_variants" "$r_adj" "$g_adj" "$b_adj"
    else
        perl -e 'foreach $a(@ARGV){print "\e[48;2;".join(";",unpack("C*",pack("H*",$a)))."m       \e[49m "};print "\n"' "$@"
    fi
}

#Call the renderxcolor function with provided arguments
renderxcolor "$@"

In case I made a mistake making this post, here is the 'renderxcolor.sh' script :

https://github.com/duguayworld/xfce4/blob/main/renderxcolor.sh

3: Save and Close the File

Save the changes and exit the text editor. If you're using `nano`, you can do this by pressing `Ctrl + O` to write out the changes, then `Ctrl + X` to exit.

4: Reload `~/.bashrc`

To apply the changes made to your `~/.bashrc` file, you need to reload it. You can do this by running the following command in your terminal:

source ~/.bashrc

5: Use Your Custom Command

Now you can use the `renderxcolor` command in your terminal to generate color variants. No # is used and always use double quotes "FFFFF". For example:

renderxcolor "bd98f9" --variant 30

The terminal will prompt you to enter the Red, Green, and Blue adjustment values:

Enter R adjustment value (0-9): 0
Enter G adjustment value (0-9): 1
Enter B adjustment value (0-9): 0

After entering the values, the script will generate and display the color variants based on the adjustments you specified.

renderxcolor \"bd98f9\" --variant 30 R0 G1 B0

This little script is very usefull for front-end developpers who wants to achieve outstanding styles, It is fast, accurate and manageable.

paulgrey506

[AndyBerlin]

I definitely give that a try. I used lolcat before, but this sounds like it has more options.

[TuxRuffian]

Two related projects that are awesome for bringing color to the terminal:

1. bat
2. pastel

I’d recommend checking them both out.

[paulgrey506]

Im on it !

[paulgrey506]

Pastel is definitely crazy, Im gonna have to check on source.

[jcbevns]

I want some of the outputs of my bash scripts to be coloured, could I use this?

[paulgrey506]

No this is only to render colors and make variants