Because {NGROUPS_MAX} may become variable, its value should be obtained
using sysconf(3). If a #define is used anyway, it should be obtained by
including <limits.h> as that is in POSIX like getgroups(2) itself is.
<sys/param.h> is not in POSIX.
MFC after: 1 week
system callers of getgroups(), getgrouplist(), and setgroups() to
allocate buffers dynamically. Specifically, allocate a buffer of size
sysconf(_SC_NGROUPS_MAX)+1 (+2 in a few cases to allow for overflow).
This (or similar gymnastics) is required for the code to actually follow
the POSIX.1-2008 specification where {NGROUPS_MAX} may differ at runtime
and where getgroups may return {NGROUPS_MAX}+1 results on systems like
FreeBSD which include the primary group.
In id(1), don't pointlessly add the primary group to the list of all
groups, it is always the first result from getgroups(). In principle
the old code was more portable, but this was only done in one of the two
places where getgroups() was called to the overall effect was pointless.
Document the actual POSIX requirements in the getgroups(2) and
setgroups(2) manpages. We do not yet support a dynamic NGROUPS, but we
may in the future.
MFC after: 2 weeks
Stop calling system calls "function calls".
Use "The .Fn system call" a-la "The .Nm utility".
When referring to a non-BSD implementation in
the HISTORY section, call syscall a function,
to be safe.
request for it something like it. It was poorly worded and too
far from both POSIX wording and normal (mal)practice by referring to
sysconf(_SC_NGROUPS_MAX) instead of {NGROUPS_MAX} or NGROUPS. POSIX.1
uses curly braces to mark up "symbolic constants or limits [that may
be] defined in certain headers". Since we don't document this markup,
don't use it. Just use NGROUPS_MAX.
in a bunch of man pages.
Use the correct .Bx (BSD UNIX) or .At (AT&T UNIX) macros
instead of explicitly specifying the version in the text
in a bunch of man pages.
