108 lines
3.4 KiB
Plaintext
108 lines
3.4 KiB
Plaintext
# gethostname.m4 serial 15
|
|
dnl Copyright (C) 2002, 2008-2023 Free Software Foundation, Inc.
|
|
dnl This file is free software; the Free Software Foundation
|
|
dnl gives unlimited permission to copy and/or distribute it,
|
|
dnl with or without modifications, as long as this notice is preserved.
|
|
|
|
# Ensure
|
|
# - the gethostname() function,
|
|
# - the HOST_NAME_MAX macro in <limits.h>.
|
|
AC_DEFUN([gl_FUNC_GETHOSTNAME],
|
|
[
|
|
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
|
|
gl_PREREQ_SYS_H_WINSOCK2
|
|
|
|
dnl Where is gethostname() defined?
|
|
dnl - On native Windows, it is in ws2_32.dll.
|
|
dnl - Otherwise it is in libc.
|
|
GETHOSTNAME_LIB=
|
|
AC_CHECK_FUNCS([gethostname], , [
|
|
AC_CACHE_CHECK([for gethostname in winsock2.h and -lws2_32],
|
|
[gl_cv_w32_gethostname],
|
|
[gl_cv_w32_gethostname=no
|
|
gl_save_LIBS="$LIBS"
|
|
LIBS="$LIBS -lws2_32"
|
|
AC_LINK_IFELSE([AC_LANG_PROGRAM([[
|
|
#ifdef HAVE_WINSOCK2_H
|
|
#include <winsock2.h>
|
|
#endif
|
|
#include <stddef.h>
|
|
]], [[gethostname(NULL, 0);]])], [gl_cv_w32_gethostname=yes])
|
|
LIBS="$gl_save_LIBS"
|
|
])
|
|
if test "$gl_cv_w32_gethostname" = "yes"; then
|
|
GETHOSTNAME_LIB="-lws2_32"
|
|
fi
|
|
])
|
|
AC_SUBST([GETHOSTNAME_LIB])
|
|
|
|
if test "$ac_cv_func_gethostname" = no; then
|
|
HAVE_GETHOSTNAME=0
|
|
fi
|
|
|
|
gl_PREREQ_HOST_NAME_MAX
|
|
])
|
|
|
|
# Provide HOST_NAME_MAX when <limits.h> lacks it.
|
|
AC_DEFUN([gl_PREREQ_HOST_NAME_MAX], [
|
|
dnl - On most Unix systems, use MAXHOSTNAMELEN from <sys/param.h> instead.
|
|
dnl - On Solaris, Cygwin, BeOS, use MAXHOSTNAMELEN from <netdb.h> instead.
|
|
dnl - On mingw, use 256, because
|
|
dnl <https://docs.microsoft.com/en-us/windows/desktop/api/winsock/nf-winsock-gethostname> says:
|
|
dnl "if a buffer of 256 bytes is passed in the name parameter and
|
|
dnl the namelen parameter is set to 256, the buffer size will always
|
|
dnl be adequate."
|
|
dnl With this, there is no need to use sysconf (_SC_HOST_NAME_MAX), which
|
|
dnl is not a compile-time constant.
|
|
dnl We cannot override <limits.h> using the usual technique, because
|
|
dnl gl_CHECK_NEXT_HEADERS does not work for <limits.h>. Therefore retrieve
|
|
dnl the value of HOST_NAME_MAX at configure time.
|
|
AC_CHECK_HEADERS_ONCE([sys/param.h])
|
|
AC_CHECK_HEADERS_ONCE([sys/socket.h])
|
|
AC_CHECK_HEADERS_ONCE([netdb.h])
|
|
AC_CACHE_CHECK([for HOST_NAME_MAX], [gl_cv_decl_HOST_NAME_MAX], [
|
|
gl_cv_decl_HOST_NAME_MAX=
|
|
AC_EGREP_CPP([lucky], [
|
|
#include <limits.h>
|
|
#ifdef HOST_NAME_MAX
|
|
lucky
|
|
#endif
|
|
], [gl_cv_decl_HOST_NAME_MAX=yes])
|
|
if test -z "$gl_cv_decl_HOST_NAME_MAX"; then
|
|
dnl It's not defined in <limits.h>. Substitute it.
|
|
if test "$gl_cv_w32_gethostname" = yes; then
|
|
dnl mingw.
|
|
gl_cv_decl_HOST_NAME_MAX=256
|
|
else
|
|
AC_COMPUTE_INT([gl_cv_decl_HOST_NAME_MAX], [MAXHOSTNAMELEN], [
|
|
#include <sys/types.h>
|
|
#if HAVE_SYS_PARAM_H
|
|
# include <sys/param.h>
|
|
#endif
|
|
#if HAVE_SYS_SOCKET_H
|
|
# include <sys/socket.h>
|
|
#endif
|
|
#if HAVE_NETDB_H
|
|
# include <netdb.h>
|
|
#endif
|
|
],
|
|
[dnl The system does not define MAXHOSTNAMELEN in any of the common
|
|
dnl headers. Use a safe fallback.
|
|
gl_cv_decl_HOST_NAME_MAX=256
|
|
])
|
|
fi
|
|
fi
|
|
])
|
|
if test "$gl_cv_decl_HOST_NAME_MAX" != yes; then
|
|
AC_DEFINE_UNQUOTED([HOST_NAME_MAX], [$gl_cv_decl_HOST_NAME_MAX],
|
|
[Define HOST_NAME_MAX when <limits.h> does not define it.])
|
|
fi
|
|
])
|
|
|
|
# Prerequisites of lib/gethostname.c.
|
|
AC_DEFUN([gl_PREREQ_GETHOSTNAME], [
|
|
if test "$gl_cv_w32_gethostname" != "yes"; then
|
|
AC_CHECK_FUNCS([uname])
|
|
fi
|
|
])
|