Multi-Firefox Fixer: Run multiple versions of Firefox simultaneously! (note: doesn't work on Windows)

multi-firefox-fixer.sh

#!/bin/bash

if [ "$1" = "-h" -o "$1" = "--help" ]; then cat <<EOF
Multi-Firefox Fixer - v0.2 - 4/26/2011
http://benalman.com/

Usage: `basename "$0"`

Run this shell script from beside (in the same parent directory as) one or more
Firefox*.app or Aurora*.app applications and it will "fix" those Firefoxes to
always use an app-named profile. For example, if an application is named
"Firefox 2.0.app" then the "Firefox 2.0" profile will always be loaded when
that application is run. This allows multiple versions of Firefox to be running
simultaneously.

Note that upon first run of a "fixed" Firefox, an app-named profile will need
to be created. This can be done in the dialog that Firefox displays, just be
sure to name it correctly!

Copyright (c) 2011 "Cowboy" Ben Alman
Dual licensed under the MIT and GPL licenses.
http://benalman.com/about/license/
EOF
exit; fi

ERR='ERROR: No Firefox*.app or Aurora*.app apps found in current directory!'
for ff in Firefox*.app Aurora*.app; do if [ -d "$ff" ]; then ERR=; fi; done
if [ "$ERR" ]; then echo "$ERR"; echo "For usage instructions, run: \
`basename "$0"` -h"; exit 1; fi

for ff in Firefox*.app Aurora*.app; do
  ROOT="$ff/Contents/MacOS"
  BIN="$ROOT/firefox-bin"
  echo $ff
  if [ -z "`file "$BIN" | grep 'shell script'`" ]; then
    echo " - Backing up firefox-bin executable to firefox.bin (first run only)."
    mv "$BIN" "$ROOT/firefox.bin"
  fi
  if [ -f "$BIN" ]; then
    echo " - Updating firefox-bin script."
  else
    echo " - Creating firefox-bin script."
  fi
  cat > "$BIN" <<'EOF'
#!/bin/bash
"`echo $0 | perl -pe 's/-bin$/.bin/'`" -P \
"`echo $0 | perl -pe 's#.*/((?:Aurora|Firefox)[^/]*)\.app/.*#\1#'`"
EOF
  chmod +x "$BIN"
done

echo 'All done!'

usage.txt

cowboy at Cowbook in /Applications/Web Browsers
$ ls
Aurora.app             Firefox 4.0.app        Opera 9.64.app
Chromium.app           Google Chrome.app      Safari 3.2.1.app
Firefox 2.0.app        Opera 10.10.app        Safari 4.0.5.app
Firefox 3.0.app        Opera 10.63.app        WebKit.app
Firefox 3.5.app        Opera 11.00.app        chrome-console-text.sh
Firefox 3.6.app        Opera 11.10.app        multi-firefox-fixer.sh

cowboy at Cowbook in /Applications/Web Browsers
$ ./multi-firefox-fixer.sh
Firefox 2.0.app
 - Backing up firefox-bin executable to firefox.bin (first run only).
 - Creating firefox-bin script.
Firefox 3.0.app
 - Backing up firefox-bin executable to firefox.bin (first run only).
 - Creating firefox-bin script.
Firefox 3.5.app
 - Backing up firefox-bin executable to firefox.bin (first run only).
 - Creating firefox-bin script.
Firefox 3.6.app
 - Backing up firefox-bin executable to firefox.bin (first run only).
 - Creating firefox-bin script.
Firefox 4.0.app
 - Backing up firefox-bin executable to firefox.bin (first run only).
 - Creating firefox-bin script.
Aurora.app
 - Backing up firefox-bin executable to firefox.bin (first run only).
 - Creating firefox-bin script.
All done!