Install PWAs on Linux and Unix-like systems.

pwa.sh

#!/bin/sh

# Public domain.

VERSION=0.1

show_help() {
cat <<END
Version $VERSION
Usage: $0 [OPTION]
Creates a web app launcher for Chromium based browsers.

Options:
    -i <APP_NAME> <URL> [BROWSER]   Install PWA app for URL.
    -u <APP_NAME>                   Uninstall PWA app.
    -l                              List PWAs installed with this script in
                                    '\${HOME}/.local/share/applications'.
    -h                              Show this help message and exit.
Arguments:
    URL         Web address for the PWA, e.g., https://example.com.
    APP_NAME    Specific name of the application, e.g., "Example App".
    BROWSER     Optional Chromium based browser executable (default: chromium).
END
}

create_app_id() {
    echo "$1" | tr '[:upper:]' '[:lower:]' | sed 's/[^a-z0-9]/-/g' | awk '{print $1"-pwa"}'
}

DESKTOP_MENU_PATH="${HOME}/.local/share/applications"
FAVICON_SIZES="256 128 96 64 48 32 24 16"

install() {
    MIN_ARGS="2"
    MAX_ARGS="3"
    if [ $# -ne "$MIN_ARGS" ] && [ $# -ne "$MAX_ARGS" ]; then
        echo "Error: Expected $MIN_ARGS or $MAX_ARGS arguments, but got $#." >&2
        show_help
        exit 1
    fi
    BROWSER=$3
    if [ -z "$BROWSER" ]; then
        BROWSER=chromium
    fi
    BROWSER_CMD=$(command -v "$BROWSER")
    if [ -z "$BROWSER_CMD" ]; then
        echo "Error: '${BROWSER}' is not installed." >&2
        exit 1
    fi
    URL=$2
    APP_NAME=$1
    DOMAIN=$(echo "$URL" | awk -F/ '{print $3}')
    APP_ID=$(create_app_id "$APP_NAME")

    mkdir -p "$DESKTOP_MENU_PATH"

    DESKTOP_MENU_FILE="${DESKTOP_MENU_PATH}/${APP_ID}.desktop"
cat > "$DESKTOP_MENU_FILE" <<END
#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Terminal=false
Type=Application
Name=${APP_NAME}
Exec=${BROWSER_CMD} --profile-directory=Default --app=${URL}
Icon=${APP_ID%.*}
StartupWMClass=${DOMAIN}
END
    chmod +x "$DESKTOP_MENU_FILE"
    
    if command -v update-desktop-database > /dev/null 2>&1; then
        update-desktop-database "$DESKTOP_MENU_PATH"
    fi
    echo "created: '${DESKTOP_MENU_FILE}'"
    
    for size in $FAVICON_SIZES; do
        (
            FAVICON_SERVICE_URL="https://www.google.com/s2/favicons?domain=${URL}&sz=${size}"
            TMP_ICON=$(mktemp /tmp/tmp.XXXXXXXX.png)
            
            curl -sLo "$TMP_ICON" "$FAVICON_SERVICE_URL"
            
            FILE_FMT=$(file --brief "$TMP_ICON")
            if ! echo "$FILE_FMT" | grep -q "PNG image data"; then
                echo "${size}x${size} icon must be a PNG image data instead got: ${FILE_FMT}."
                rm -f "$TMP_ICON"
                continue
            fi
            
            xdg-icon-resource install --size "$size" "$TMP_ICON" "$APP_ID"
        ) &
    done
    echo "installed icons '${APP_ID}' successfully."
    wait

    echo "Web app '${APP_NAME}' created successfully!"
}

uninstall() {
    NUM_ARGS="1"
    if [ $# -ne "$NUM_ARGS" ]; then
        echo "Error: Expected ${NUM_ARGS} arguments, but got $#." >&2
        show_help
        exit 1
    fi
    APP_NAME=$1
    APP_ID=$(create_app_id "$APP_NAME")
    DESKTOP_MENU_FILE="${DESKTOP_MENU_PATH}/${APP_ID}.desktop"

    if [ ! -e "$DESKTOP_MENU_FILE" ]; then
        echo "PWA app '${APP_NAME}' is not installed."
        exit 1
    fi
    
    rm -f "$DESKTOP_MENU_FILE"

    for size in $FAVICON_SIZES; do
        xdg-icon-resource uninstall --size "$size" "$APP_ID"
    done

    echo "removed: '${DESKTOP_MENU_FILE}'"
    echo "removed icons '${APP_ID}' successfully."
    echo "Web app '${APP_NAME}' uninstalled successfully!"
}

list() {
    if [ ! -d "$DESKTOP_MENU_PATH" ]; then return 0; fi
    for desktop_file in "${DESKTOP_MENU_PATH}/*-pwa.desktop"; do
        echo "  - $(grep -m 1 "^Name=" "$desktop_file" | cut -d '=' -f2)"
    done
}

while getopts "iulh" opts; do
    case "$opts" in
        i) shift $((OPTIND - 1)); install "$@"; exit 0 ;;
        u) shift $((OPTIND - 1)); uninstall "$@"; exit 0 ;;
        l) list; exit 0 ;;
        h) show_help ; exit 0 ;;
        *) show_help; exit 1 ;;
    esac
done