Re: Header files with enums instead of defines?

From: Matthew D. Fuller (fullermd_at_over-yonder.net)
Date: 12/22/04

  • Next message: Garance A Drosihn: "Re: Header files with enums instead of defines?" 
    Date: Wed, 22 Dec 2004 12:13:14 -0600
To: Poul-Henning Kamp <phk@phk.freebsd.dk>

    On Wed, Dec 22, 2004 at 06:45:16PM +0100 I heard the voice of
    Poul-Henning Kamp, and lo! it spake thus:
    >
    > One of my pet peeves is that comples system calls have no way to
    > convey additional information about why the return a given return
    > value like EPERM.
    >
    > I would almost advocate adding a char[X] to each thread and a system
    > call which could retrieve it. Complex system calls like
    > mount/nmount, ioctl and similar could then stick an explanation into
    > that string which strerror(3) or err(3) and similar functions could
    > pull out and give the user.

    I do roughly this in the errno-ish facility in my sadly-dormant
    libpostal project. My error structure looks like

    struct postal_errfoo_t
    {
        unsigned int postal_errno;
        char postal_errstr[POSTAL_ERRSTR_LEN];
    };

    Of course, I get to mandate that you use postal_errno() and
    postal_errstr() to retrieve the data. I use (1<<15) as a flag in the
    errno int (at least, until I get a WHOLE lot more error conditions
    that I have now) for when there's an extra message to be returned. I
    don't think I actually USE the capability anywhere right now, but it's
    designed in. 

    -- 
Matthew Fuller     (MF4839)   |  fullermd@over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
"The only reason I'm burning my candle at both ends, is because I
      haven't figured out how to light the middle yet"
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  • Next message: Garance A Drosihn: "Re: Header files with enums instead of defines?"