@node unistd.h
@section @file{unistd.h}

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html}

Gnulib module: unistd

Portability problems fixed by Gnulib:
@itemize
@item
This header file is missing on some platforms:
MSVC 14.
@item
The SEEK_* macros are not defined in this file on some platforms:
mingw.
@item
The *_FILENO macros are not defined in this file on some platforms:
OS/2 EMX, mingw.
@item
The @code{_exit} function is not declared in this file on some platforms:
mingw.

@item
Some platforms provide a @code{NULL} macro that cannot be used in arbitrary
expressions:
NetBSD 5.0
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@end itemize