You might also consider sourcing your login environment rc file (presuming of course you use a shell that supports separate "environment rc" and "interactive rc" file). For example I use zsh and pure environment settings are in ~/.zshenv while interactive aliases and prompts and what not are in ~/.zshrc. If I need a cron job to have the same environment I'm used to at a prompt I just source ~/.zshenv. Even if your shell doesn't explicitly support this it might be worth breaking environment setup out into another file you can source from stuff run from cron.