[nuttx] Porting Sqlite to NuttX - undefined reference to 'utimes' and 'ftruncate'

[[e-mail] [nuttx]]

Hi NuttX Group members,
In these days, I tried to port Sqlite to NuttX. Now I have successfully cross-compiled Sqlite as a library on Atmel Studio 7 using NuttX API. When I tried to use Sqlite in my application and found there were 2 undefined reference errors at the final linking process. One error was 'undefined reference to 'utimes' and the other was 'ftruncate'.
The question is where can I find proper source code of these 2 undefined functions? I hope there was no license conflict, so we can submit it to NuttX mainline.


Thanks & Best Regards

[[e-mail] [nuttx]]

There are several file system features that are not currently supported by NuttX. ftruncate/truncate is one that is noted in the TODO list:

https://bitbucket.org/nuttx/nuttx/src/aa1a06899935b5a7be1545f4277124e1f675a68e/TODO?at=master&fileviewer=file-view-default#TODO-1745

utimes() is another. Currently only FAT supports file times and there is no file system interface to change file times. http://pubs.opengroup.org/onlinepubs/009695399/functions/utimes.html

You can see the current file system interface in the file include/nuttx/fs/fs.h, struct mountpt_operations. Any new file system operations would need to add methods to that structure (and implement them in all existing file systems... that is the hard part).

I suspect that you could just stub out utimes(). But fruncate() is a problem. ftruncate can be used to either make a file smaller or larger. Larger is not a problem; I think you can do that with lseek (http://pubs.opengroup.org/onlinepubs/009695399/functions/lseek.html) or just by extending the file with zero data (I have never tried lseek for that purpose, however.). But I don't know if any way to make a file smaller without ftruncate.

I assume that SQLite really just wants to create a fixed size file form random access. If that is the case, there are other ways around that.

Greg

[[e-mail] [nuttx]]

Thanks for your suggestion, Greg.

Yes, ftruncate is a big problem to be implemented on current NuttX. I will try lseek as you suggested.


Best Regards

[[e-mail] [nuttx]]

This post might be inappropriate. Click to display it.