dynamic-browser

#!/bin/sh
set -eu
mode="$1"
url="$2"
chromium_standard='chromium'
chromium_private='chromium --incognito'
firefox_standard='firefox'
firefox_private='firefox --private-window'
if pgrep 'chromium' >/dev/null 2>&1
then
  browser="chromium_${mode}"
else
  browser="firefox_${mode}"
fi
echo "Launching: ${!browser} $2"
${!browser} "$2"

dynamic-browser.desktop

# /usr/share/applications/dynamic-browser.desktop

[Desktop Entry]
Version=1.0
Comment=Access the Internet
StartupNotify=true
Terminal=false
Icon=chromium
Type=Application
Categories=Network;WebBrowser;
MimeType=application/pdf;application/rdf+xml;application/rss+xml;application/xhtml+xml;application/xhtml_xml;application/xml;image/gif;image/jpeg;image/png;image/webp;text/html;text/xml;x-scheme-handler/ftp;x-scheme-handler/http;x-scheme-handler/https;
Actions=new-window;new-private-window;

[Desktop Action new-window]
Name=New Window
Exec=/usr/local/bin/dynamic-browser standard

[Desktop Action new-private-window]
Name=New Private Window
Exec=/usr/local/bin/dynamic-browser private