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1799 :: ioctl support for nim.

• xyz32 (orginal) [2015-11-13T15:14:25+01:00] view original

  As some of you may know, I am working on a beaglebone black library for Nim. (You can find some more information here: http://forum.nim-lang.org/t/1318#8259 ).

  In the last month or so I worked on testing and improving the performance of the library (Which turned out very well, her is my NimBot battling with a doorstep https://vimeo.com/137852470 ).

  I am now working on bringing i2c support (and other communication buses). To make this work I need low level control to set up the i2c drivers for the bus I want to use.

  In C, ioctl ( http://man7.org/linux/man-pages/man2/ioctl.2.html ) provides this functionality, but I was wondering if there is a pure Nim way of doing it as well. As far as I know ioctl is not portable.

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• Araq (orginal) [2015-11-13T17:04:02+01:00] view original

  Not sure I understand your concerns. You can either talk to the Linux kernel via assembler or via the C library. To wrap the C library you can use c2nim. Or you can produce a Nim DSL generating assembler. The latter is much more fun and will gain you "one hell of a guy" extra points, the former is less work.

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• Varriount (orginal) [2015-11-13T18:59:03+01:00] view original

  Is there something unique about the ioctl procedure that it can't be wrapped via the usual C FFI pragmas?

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• xyz32 (orginal) [2015-11-13T21:13:00+01:00] view original

  @Araq My concern was not to duplicate the work, if the ioctrl functionality can be reproduced at ease in nim. I guess not judging by your response. I will try c2nim see what I get, and if that does not work I will go for the "one hell of a guy" bonus.

  @Varriount I was thinking about portability mostly (there are some embedded windows things out there as well, a French airport was jut taken down by a bug in Windows 3.1), but I guess MinGW will take care of that? And in my first attempt I tried to do the wrapping manually...

  And my last concern, I see ioctrl as part of the Nim system library functionality. Does that make sense?

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• Varriount (orginal) [2015-11-14T01:14:20+01:00] view original

  Well just wrap it in a when defined(posix) block (And check if there's a Linux specific define instead). Alternately, if the system call is available via DLL, use the dll loading module.

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