Windows sockets functions look on the outside like they behave similarly
to POSIX functions, but there are many subtle and glaring differences,
including errors reported via WSAGetLastError, read, write, and close do
not work on sockets, setsockopt takes a (char *) rather than (void *),
etc.
This header implements wrappers that coerce more POSIX-like behavior
from these functions, making portable code easier to develop.
BENEFITS:
One does not necessarily need to sprinkle #ifdefs around code to handle
the Windows and non-Windows behavior when porting code.
CAVEATS:
There may be performance implications with the 'mother-may-I'
approach to determining if a descriptor is a socket or a file.
The errno mappings are not 100% what one might expect compared to POSIX
since there were not always good 1:1 equivalents from the WSA errors.
Simplify autoconf checks by using AC_CHECK_FUNCS/HEADERS.
Clarify some ambiguous dependencies around strnlen/strndup.
Unconditionally enable pidwraptest for all arc4random implementations.
Remove HAVE_VASPRINTF conditional, since asprintf requires vasprintf.
ok @doug
it seems that including stdarg.h is needed for defining va_list
environment is hpux 11.31(ia64) with gcc 4.7.1.
without stdarg.h, I got compilation error like this.
"error: 'va_list' undeclared (first use in this function)"
I checked with gcc -E, then I noticed that __va_list is defined but va_list is not.
"typedef __gnuc_va_list __va_list;"
with including stdarg.h, va_list is defined.
"typedef __gnuc_va_list va_list;"
