On Friday 28 November 2008 15:00:23 Michael Kerrisk wrote: > Rob, > > On Thu, Nov 27, 2008 at 8:35 AM, Rob Landley <rob@xxxxxxxxxxx> wrote: > > http://kernel.org/doc/man-pages/online/pages/man2/uname.2.html > > > > It says the length of the fields was unspecified. > > Yup -- that's what POSIX says. Posix doesn't specify init or mount either. "Posix doesn't specify" doesn't forbid something else from specifying it. > As noted in the first para of the description, > the fields of the structure are null-terminated, which, in the typical > case, makes it quite possible to use them without knowing their > (maximum) lengths. Use a field, yes. Iterate though the fields/find the next field, no. (I suppose you can memset the memory block you feed to the syscall to "null" and iterate through to the next non-null character, as long there's a guarantee none of the fields will be zero length.) > And indeed, a portable program should not care. When I start writing portable programs that I intend to support on Dragonfly BSD, I'll let you know. "Posix portable" includes Windows NT and strange IBM mainframes. > > so leaving it unspecified is silly. It's part of the current kernel's > > binary abi, and the value is currently 65. > > And that last piece is exactly part of the problem, because once upon > a time (okay: a long time ago, now), it was true that "the value is > currently 9". > > It seems to me that all the info you needed was there in the page, but > you didn't read the whole page. True. I didn't notice that there was a "notes" field (my screen ended with "return value", "errors", and "conforming to", didn't hit page down) that was larger than the rest of the page. My bad. > The question is, whether the page > could/should provide more clues to make sure that the reader is > pointed to the fine details (which, for the reasons I described above, > are often not needed). I thought the point of the man pages on kernel.org was to document the kernel API. (If you're programming against glibc I assume that has its own documentation somewhere.) I suppose those of us programming against uClibc or other low level interfaces can always just look at the kernel source code. > Cheers, > > Michael Rob -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
