2 dnl Copyright (C) 2009-2011 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_SELECT],
9 AC_REQUIRE([gl_HEADER_SYS_SELECT])
10 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
11 AC_REQUIRE([gl_SOCKETS])
12 if test "$ac_cv_header_winsock2_h" = yes; then
16 dnl On Interix 3.5, select(0, NULL, NULL, NULL, timeout) fails with error
18 AC_CHECK_HEADERS_ONCE([sys/select.h])
19 AC_CACHE_CHECK([whether select supports a 0 argument],
20 [gl_cv_func_select_supports0],
22 AC_RUN_IFELSE([AC_LANG_SOURCE([[
23 #include <sys/types.h>
26 #include <sys/select.h>
30 struct timeval timeout;
33 return select (0, (fd_set *)0, (fd_set *)0, (fd_set *)0, &timeout) < 0;
34 }]])], [gl_cv_func_select_supports0=yes], [gl_cv_func_select_supports0=no],
38 # Guess no on Interix.
39 interix*) gl_cv_func_select_supports0="guessing no";;
40 # Guess yes otherwise.
41 *) gl_cv_func_select_supports0="guessing yes";;
46 case "$gl_cv_func_select_supports0" in