[Create icons] How to create different sized icons for apps in Linux #linux #bash

icongen.sh

#!/bin/bash

# This will create icons in their respective
# folders in "$HOME"/.local/share/icons/...

# Usage: icongen iconfile

# Check usage
if [[ $# -ne 2 ]]; then
    echo "Usage: $0 icon_file new_icon_name"
    exit 1
fi

# Check if the icon file provided in the first
# argument actually exists
if [ ! -f $1 ]; then
    echo error: file $1 does not exist
    exit 1
fi

# Get the icon info, so the dimension can be extracted
icon_info=$(file $1)

# regex to extract the dim in the format "300 x 300"
dim_regex='[0-9]+[[:space:]]x[[:space:]][0-9]+'

# Get the icon dimmension
if [[ $icon_info =~ $dim_regex ]]; then
    dim="${BASH_REMATCH[0]}"
    
    echo Icon size: $dim

    # Extract the first number, e.g. "300" from "300 x 300"
    if [[ $dim =~ ^[0-9]+ ]]; then
        dim1=${BASH_REMATCH[0]}
        # Array with the icon sizes to be genrated
        icon_sizes=(16 24 32 48 64 96 128 256 512)
        for icon_size in ${icon_sizes[*]}
        do
            # Check if the current dimension is smaller or equal
            # than the original icon
            if [[ "$dim1" -ge "$icon_size" ]]; then
                # resize the icon to the current icon_size creating a new file
                convert -resize "$icon_size"x"$icon_size" $1 $2
                # move it to the proper folder
                dest="$HOME"/.local/share/icons/hicolor/"$icon_size"x"$icon_size"/apps
                mv -i $2 $dest
                # Check if the last command succeeded
                if [ $? -eq 0 ]; then
                    # Success
                    echo "$icon_size"x"$icon_size" icon created at $dest created
                else
                    # Failure
                    echo failed to create "$icon_size"x"$icon_size" icon
                fi
            fi
        done
    fi
else
    echo error: "icon's dimmension couldn't be extracted"
    exit 1
fi