In an attempt to "properly" implement a standard configuration of my preferred shell,
bash, for use across multiple platforms, I've come across some confusion when dealing with terminals that are inconsistent with their choice of shell start-up types (login or interactive).
Bash Start-Up Files
From the bash manual, I've determined the difference between the start-up files and order/cases in which they are sourced (
~/.profile for login shells, and
~/.bashrc for interactive non-login shells). The documentation suggested that you store your bash-specfic login configuration in
~/.bash_profile and your bash-specific interactive ones in your
~/.bashrc. The manual itself even suggested adding
if [ -f ~/.bashrc ]; then source ~/.bashrc; fi to the
~/.bash_profile file so login shells inherit your interactive shell settings.
From what I've read in the manual and in various online forums/docs, it also seemed prudent to abstract your non-bash specific login configuration to
~/.profile since other shells can source this file. This may be an edge-case for people who may use Bourne shell in addition to bash (which is not really likely in my case), but it seems like a good habit to form.
So far this all seems pretty straight forward and logical, especially in an environment where the distinction between the various shell start-up types are apparent: on systems or terminals where the command-line is the primary interface, login shells are your primary session shells, interactive shells are subsequent shells launched in that session, and your non-interactive shells are script-running shells.
The real confusion is what constitutes a login shell when your shell is started from a terminal within a GUI environment where you are already authenticated to the system? It seems to me that the default behavior in Mac OSX Terminal.app is for the shell running in each window to start a login shell, whereas in xterm, each new window is an interactive shell.
It is possible that I am seeing a problem where one does not exist, however consider the following: the terminal situation suggests that I put the vast majority of my configuration in
~/.bashrc to avoid losing functionality should I be working on a terminal that starts bash as an interactive shell. Being unfamiliar with the intricacies of when bash might be spawned as interactive shells, I have to rely on this statement that abusing
~/.bashrc like this will eventually cause problems where login shell configuration being misplaced is detrimental to normal shell functioning. It isn't hard to imagine that problems might arise when you ignore the manual's advice and use configuration files inappropriately.
Since you can't really rely on using
~/.bashrc as your catch-all, it seems like you might need to treat your
~/.bashrc files differently depending on the terminal you are using. This seems like it would result in a lot of headaches and is counter to the purpose of having these distinct start-up files in the first place!
So finally my questions are as follows:
- How do current Bash shell users address the issue of GUI terminal inconsistencies between starting login and interactive shells?
- How do you create a single-set of bash start-up files for cross-platform (and cross-terminal) use, without running into problems?
Thank you for your assistance and advice.