getopt - command line options parsing

[jd-soc]

Hi all,

I'm trying to use getopt (from <unistd.h>) in some LPC-projects, where I have a small shell running.
Part of this shell is doing the command line processing, where I then need to process different kind of options.
I would like this to be as generic as possible, hence getopt().

The problem I'm facing at the moment is when playing around with heap/stack, I often get a HardFault.
This is because I don't know the memory usage/needs of getopt().

Is there a way to estimate its max usage, without having access to the implementation?

I know using such function on an embedded target might be discouraged, but re-inventing the wheel each time is also not really convenient, nor maintainable.

(Or has someone an alternative or better ideas ?)

My configuration:
LPCOpen C++ project with NewLib
MCUXpresso
LPC1769

Thanks for your help!

[jeremyzhou]

Hi Julien Delbergue,

Thank you for your interest in NXP Semiconductor products and 

for the opportunity to serve you.

Optimizing the heap and stack may be a good way, and in the MCUXpresso IDE user's guide, 11.9 More advanced heap/stack placement illustrates the detailed information.

Hope this helps.

Have a great day,
TIC

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[jd-soc]

Hi jeremyzhou,
Thanks for your answer.

I don't think it actually is because of memory layout (12.9 btw in the latest user's guide).
I suspect it is because I'm using C++, and most likely this getopt implementation is using malloc, which is discouraged in C++ from what I am reading.

Could you maybe confirm that malloc is being used in your getopt implementation ?
I'm still open to alternatives or other ideas.

Cheers,

Julien