functions, with a little bit of a caution that the page rounding
behavior isn't mentioned in standards documents that mention brk/sbrk.
Klaus removed this before, but I'm not sure why, and I've been unable
to reach him about the matter after trying for several days. The
information about the behavior has always been in the page and is
important for developers to know about.
issues (at least):
1) sbrk is defined as returning char *, which violates XPG
2) I'm not clear on what happens if you try to sbrk() on a negative
incr that is less than the page size. I'm guessing "nothing", but we
should document this behavior.
3) XPG says some interesting things about whether new pages are
guaranteed zeroed. We say nothing about this. We should document our
behavior.
4) It isn't clear if *we* guarantee that malloc and sbrk can be mixed
in our API (I've documented that it isn't universally portable.)
We really should clean these up, too.
Use .Fn rather than .Nm macro in HISTORY and STANDARDS sections.
Use .At and .St macros instead of spelling out "Version 6 UNIX",
"IEEE 1003.1-1988 (POSIX)", etc.
