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Re: Is there a way to have a local version of a header file?




On Sat, 18 Mar 2017, Ævar Arnfjörð Bjarmason wrote:

On Sat, Mar 18, 2017 at 3:29 PM, David Lang <david@xxxxxxx> wrote:
for an embedded project built inside the Arduino IDE, (alternate firmware
for a home automation project) there is a need to set a number of parameters
that we really don't want in the main repo (wifi network IDs/passwords)

right now, we have these things set as #defines in a header file.

We need to distribute a base version of this file for new people to get
started.

Is there any way to have git define a file in such a way that if it doesn't
exist in the worktree it gets populated, but if it does exist it doesn't get
overwritten? (as I type this, I'm thinking a trigger may work, but we need
it to work on Linux, Windows and OSX)

Any thoughts on a sane way to handle this situation?

There's no sane way to do what you're describing without renaming the file.

But the sanest way to do this is to have a config.h.example

Then you have "/config.h" in the .gitignore file.

And you tell the users to copy the *.example file to *.h, and your
program then includes the *.h file.

If you wanted to provide defaults you could just #include the
config.h.example first, so #defines in the *.h file would clobber
those in the *.example.

That's what we currently have (user_config.h and user_config_override.h)

I was hoping to not have the situation where downloading and trying to compile will complain about a missing include file (if the users don't copy user_config_override_example.h to user_config_override.h) while letting us do a .gitignore on user_config_override.h

for many people using this project, this is the first time they have ever compiled anything, and we have the typical set of people not reading instructions :-/

Darn, I was hoping that the scenario of needing to have a config file provided in the repo, while not overwriting local changes to it was common enough that there were some tricks available. This is a little harder as the running code doesn't have a filesystem so we are limited to what we can do in the compiler and git (no makefile even, the Arduino folks consider that too complicated, it just slurps up all .ino files in a directory and compiles them)