Re: environment variables

[Aaron Davies]

On Dec 11, 2013, at 6:06 AM, Nico Schlömer wrote:

> David T. Pierson <address@hidden> wrote:

> 
>> If you want different behavior, please be more specific about what you are 
>> really trying to accomplish.
> 
> I would like to execute a program in a shell that needs a custom path added 
> to  LD_LIBRARY_PATH. This happens in my .bashrc by default, so on the regular 
> non-screen shell I'm getting no problems.
> 
> On a detached screen however, the program will not execute with an error 
> message related to an incomplete LD_LIBRARY_PATH. Indeed,
> 
> $ env | grep LD_LIBRARY_PATH
> LD_LIBRARY_PATH=/home/nschloe/Work/FEniCS/lib/:/opt/trilinos/dev/openmpi/1.4.3/gcc/4.6.3/release/shared/lib/:/opt/netcdf/4.2.1.1/lib/:/home/nschloe/Work/FEniCS/lib:
> $ screen -L -d -m sh -c "env | grep LD_LIBRARY_PATH"
> $ cat screenlog.0
> $
> 
> so LD_LIBRARY_PATH doesn't seem to be defined in the detached shell at all.
> 
> It *does* get set in attached shells though.
> 
> Any workaround for it?

shell initialization is weird, tricky, and annoying

things to check:

is LD_LIBRARY_PATH exported? try "export | grep LD_LIBRARY_PATH". if not, 
change your .bashrc to export it.

how is your .bashrc called? the default rule in bash 3.2 (the man page i have 
most direct access to at the moment) is "When an interactive shell that is not 
a login shell is started, bash reads and executes commands from ~/.bashrc, if 
that file exists."

how is screen launching your shell? is the screen "shell" config "bash" or 
"-bash"? is it set at all, or is it defaulting to $SHELL?

do you call your .bashrc from your .bash_profile? (do you *have* a .bash_login 
or .profile?) a very common bash idiom is to have "[[ -f ~/.bashrc ]] && . 
~/.bashrc" in .bash_profile.

is this OS X or linux/bsd/cygwin windows/something else? i've heard reports of 
shell initialization differences in OS X zsh, so there might be issues in bash 
too.
-- 
Aaron Davies
address@hidden