Re: Is there a list of all the environment variables?

[Alex Humberstone]

Awesome, thanks, your post is very helpful.

Sincerely,

Alex-M-Humberstone

PhD Student

Klipsch School of Electrical Engineering

New Mexico State University (NMSU)
Las Cruces, New Mexico, USA

On Tue, 19 Jan 2021 at 09:39, Marcus Müller <mmueller@gnuradio.org> wrote:

Hi Alex!

Yep, cleaning up that, and documentating it is on my wishlist :)
So, two types of env variables:

1. gr::prefs configuration-file equivalents
2. "special" environment variables.

Re 1.: So, you might be aware of GNU Radio's preference management system: GNU Radio reads
and writes config files; (these are a bit fragile, because) there's multiple ways to
define the same configuration key, and one of these is setting an environment variable
that starts with GR_CONF; that's documented in [1][2].

Re 2.: Then, there's a couple of special environment variables that things are sensitive
against. GR_PREFS_PATH is relatively new, for example, and for reasons of causality can't
be covered by the preferences :)

GRC_BLOCKS_PATH is another older, but well-established environment variable (which can
actually be absorbed by the config system).

A grep for `getenv` tells me that's about it; of course, for example, most audio system
interfaces have their own trove of configurability, so do graphical frameworks (in our
case, X11, Qt), the typical linux runtime library loader listens to LD_LIBRARY_PATH and
various others and so on, but these are "global" sensitivities of libraries that GNU Radio
uses, not GNU Radio itself (I'm not sure knowing this helps the confused user, though...).

Best regards,
Marcus

[1] https://wiki.gnuradio.org/index.php/Configuration_Files
[2] formerly, in the doxygen docs under "Usage"

On 19.01.21 13:39, Alex Humberstone wrote:
> Dear Community,
>
> Is there a list of all the environment variables used in GNU Radio somewhere? I don't see
> anything in the documentation or in the wiki. There are a lot of obscure variables such as
> $GR_PREFS_PATH and $GR_CONF_GRC_GLOBAL_BLOCKS_PATH, and I have no idea what they all do.
> It would be really useful if they were all listed and documented somewhere. Thanks in
> advance for the help!
>
> Sincerely,
> Alex-M-Humberstone
> PhD Student
> Klipsch School of Electrical Engineering
> New Mexico State University (NMSU)
> Las Cruces, New Mexico, USA
>