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

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/limits.h.html}

Gnulib module: limits-h or gethostname
@mindex limits-h
@mindex gethostname

Portability problems fixed by Gnulib module @code{limits-h}:
@itemize
@item
The macros @code{LLONG_MIN}, @code{LLONG_MAX}, @code{ULLONG_MAX} are not
defined on some platforms:
older glibc systems (e.g. Fedora 1), AIX 5.1, HP-UX 11, OpenVMS.
@item
The macro @code{MB_LEN_MAX} is not defined on some platforms:
pcc 1.2.0.DEVEL 20220331.
@item
The macros @code{WORD_BIT}, @code{LONG_BIT} are not defined on some platforms:
glibc 2.11 without @code{-D_GNU_SOURCE}, Cygwin, mingw, MSVC 14.
@item
Macros like @code{CHAR_WIDTH} are not defined on some platforms:
glibc 2.24, NetBSD 10.0, many others.
@item
The macros @code{BOOL_MAX} and @code{BOOL_WIDTH} are not defined on
some platforms:
glibc 2.32, many others.
@item
The macro @code{BOOL_MAX} is not defined with some compilers:
clang 15.0.6.
@item
The macro @code{SSIZE_MAX} is not defined on some platforms:
MSVC 14.
@end itemize

Portability problems fixed by Gnulib module @code{gethostname}:
@itemize
@item
The @code{HOST_NAME_MAX} macro is not defined on some platforms:
macOS 11.1, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
The macro @code{SSIZE_MAX} has the wrong type,
albeit with the correct value:
32-bit glibc 2.24 (on some architectures), Cygwin 2.5.2.
@end itemize

@mindex pathmax
For @code{PATH_MAX}, Gnulib provides a module @code{pathmax} with a header
file @code{"pathmax.h"}.  It defines @code{PATH_MAX} to a constant on
platforms with a file name length limit.