Replace .bashrc, .bash_profile, .profile, etc. with something much more clean, consistent, and meaningful. Now a repo: https://github.com/josephwecker/bashrc_dispatch

new_bashrc.sh

#!/bin/bash
# License: Public Domain.
# Author:  Joseph Wecker, 2012
#
# -- DEPRICATED --
# This gist is slow and is missing .bashrc_once
# Use the one in the repo instead! https://github.com/josephwecker/bashrc_dispatch
# (Thanks gioele)
#
# Are you tired of trying to remember what .bashrc does vs .bash_profile vs .profile?
# Are you tired of trying to remember how darwin/mac-osx treat them differently from linux?
# Are you tired of not having your ~/.bash* stuff work the way you expect?
#
# Symlink all of the following to this file:
#   *  ~/.bashrc
#   *  ~/.bash_profile
#   *  ~/.profile
#   *  ~/.bash_login
#
# And then you can use these instead:
#   *  ~/.bashrc_all             sourced on every bash instantiation
#   *    ~/.bashrc_script        sourced only when non-interactive
#   *    ~/.bashrc_interactive   the one you'll probably fill up (MUTALLY EXCLUSIVE w/ .bashrc_script)
#   *      ~/.bashrc_login       sourced only when an interactive is also a login
#
# To reiterate, `.bashrc_all` will always be run first.
# Then either `.bashrc_script` OR `.bashrc_interactive` will be run next
# depending on whether or not the bash invocation is... interactive.
# Finally, sometimes, like when you first ssh into a machine or often when
# opening a new terminal window on a mac, the `.bashrc_login` will be run
# after the `.bash_interactive`. So `.bashrc_login` is the one where you'd echo
# a banner or whatever.
#
#
# In addition to the dispatching, you'll see below that you'll forever have the
# following available:
#  * $SHELL_PLATFORM   # (at the moment just 'LINUX', 'OSX', or 'OTHER')
#  * shell_is_linux
#  * shell_is_osx
#  * shell_is_interactive
#  * shell_is_script
#
# The functions are meant for clean conditionals in your new .bashrc_* scripts-
# like:
#     $  shell_is_linux && echo 'leenux!'
# or something like:
#     $  if shell_is_interactive; then echo 'interact'; fi
# etc... And now I think these comments have reached parity with the code
# itself which should be easy to extend.
#
#

[ -n "$SHELL_FOR" ] && [ $$ -eq "$SHELL_FOR" ] && exit  # Avoid recursive invocation
SHELL_FOR=$$

export SHELL_PLATFORM='OTHER'
unamestr=`uname`
if   [[ "$unamestr" == 'Linux'  ]]; then SHELL_PLATFORM='LINUX';
elif [[ "$unamestr" == 'Darwin' ]]; then SHELL_PLATFORM='OSX';
fi

if [ -z "$SHELL_DISPATCH_FUNCTIONS" ]; then
  shell_is_linux       () { return `[[ "$SHELL_PLATFORM" == 'LINUX' ]]`; }
  shell_is_osx         () { return `[[ "$SHELL_PLATFORM" == 'OSX'   ]]`; }
  shell_is_login       () { return `shopt -q login_shell`;               }
  shell_is_interactive () { return `[ -n "$PS1" ]`;                      }
  shell_is_script      () { return `! shell_is_interactive`;             }
  export -f shell_is_linux
  export -f shell_is_osx
  export -f shell_is_login
  export -f shell_is_interactive
  export -f shell_is_script
  export SHELL_DISPATCH_FUNCTIONS=1
fi

[ -z "$BASH_ENV" ] && export BASH_ENV="$BASH_SOURCE"

# Now dispatch special files
[ -f "${HOME}/.bashrc_all" ]                                 && source "${HOME}/.bashrc_all"
[ -f "${HOME}/.bashrc_script" ]      && shell_is_script      && source "${HOME}/.bashrc_script"
[ -f "${HOME}/.bashrc_interactive" ] && shell_is_interactive && source "${HOME}/.bashrc_interactive"
[ -f "${HOME}/.bashrc_login" ]       && shell_is_login       && source "${HOME}/.bashrc_login"

The exit should be a "return." For example, try this:

$ echo 'exit' >> /tmp/test.sh
$ source /tmp/test.sh

I don't know for 100% certain if it's handled exactly the same way during shell start-up, but return seems the safer bet in my book.