core.stdc.limits: Define some common filesystem limits

[ibuclaw]

The only one of interest to me is PATH_MAX, needed for a portability bug fix in dmd.

Ping the port maintainers @joakim-noah @jacob-carlborg @dkgroot @nrTQgc @redstar for adding missing systems.

[dlang-bot]

Thanks for your pull request, @ibuclaw!

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[dkgroot]

@ibuclaw
Can you please include this (so that i don't have to create a seperate pull request / review cycle).
If you do want a separate pull request instead, just let me know (i am not allowed to edit your PR, otherwise i would have fixed it up myself).

else version (DragonFlyBSD) 
{
    ///
    enum MAX_CANON      = 255;
    ///
    enum MAX_INPUT      = 255;
    ///
    enum NAME_MAX       = 255;
    ///
    enum PATH_MAX       = 1024;
    ///
    enum PIPE_BUF       = 512;
}
else version (NETBSD)
{
    ///
    enum MAX_CANON      = 255;
    ///
    enum MAX_INPUT      = 255;
    ///
    enum NAME_MAX       = 511;
    ///
    enum PATH_MAX       = 1024;
    ///
    enum PIPE_BUF       = 512;
}
else version (OPENBSD)
{
    ///
    enum MAX_CANON      = 255;
    ///
    enum MAX_INPUT      = 255;
    ///
    enum NAME_MAX       = 255;
    ///
    enum PATH_MAX       = 1024;
    ///
    enum PIPE_BUF       = 512;
}

I took the values from syslimits.h, which is not the same as plain limits.h, which mostly contains the POSIX values.

References for the other two BSD's:

• netbsd
• openbsd

FYI: DragonFlyBSD is based on an older branch of FreeBSD, so for these older type include types, the simple guess is just to replicate the values from FreeBSD and add a little todo to verify. (Not sure if that is appreciated or not by other maintainers)

Side Note: NAME_MAX is not 100% clear in it's use (might need some doc). Also it could be confused with stdio.d:FILENAME_MAX. which can differ. AFAIK: FILENAME_MAX is part of the c standard. NAME_MAX is not required to exist on every platform. Just my 2 cents.

[ibuclaw]

Thanks @dkgroot