3 dnl Find out how to get the file descriptor associated with an open DIR*.
5 # Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
6 # This file is free software; the Free Software Foundation
7 # gives unlimited permission to copy and/or distribute it,
8 # with or without modifications, as long as this notice is preserved.
12 AC_DEFUN([gl_FUNC_DIRFD],
14 AC_LIBSOURCES([dirfd.c, dirfd.h])
16 dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
17 AC_REQUIRE([AC_PROG_CPP])
18 AC_REQUIRE([AC_PROG_EGREP])
24 #else /* not HAVE_DIRENT_H */
25 # define dirent direct
27 # include <sys/ndir.h>
28 # endif /* HAVE_SYS_NDIR_H */
31 # endif /* HAVE_SYS_DIR_H */
34 # endif /* HAVE_NDIR_H */
35 #endif /* HAVE_DIRENT_H */
38 AC_CHECK_DECLS([dirfd], , , $dirfd_headers)
40 AC_CACHE_CHECK([whether dirfd is a macro],
41 gl_cv_func_dirfd_macro,
42 [AC_EGREP_CPP([dirent_header_defines_dirfd], [$dirfd_headers
44 dirent_header_defines_dirfd
46 gl_cv_func_dirfd_macro=yes,
47 gl_cv_func_dirfd_macro=no)])
49 # Use the replacement only if we have no function, macro,
50 # or declaration with that name.
51 if test $ac_cv_func_dirfd,$ac_cv_have_decl_dirfd,$gl_cv_func_dirfd_macro \
53 AC_REPLACE_FUNCS([dirfd])
55 [how to get the file descriptor associated with an open DIR*],
56 gl_cv_sys_dir_fd_member_name,
58 dirfd_save_CFLAGS=$CFLAGS
59 for ac_expr in d_fd dd_fd; do
61 CFLAGS="$CFLAGS -DDIR_FD_MEMBER_NAME=$ac_expr"
65 [DIR *dir_p = opendir("."); (void) dir_p->DIR_FD_MEMBER_NAME;],
68 CFLAGS=$dirfd_save_CFLAGS
69 test "$dir_fd_found" = yes && break
71 test "$dir_fd_found" = yes || ac_expr=no_such_member
73 gl_cv_sys_dir_fd_member_name=$ac_expr
76 if test $gl_cv_sys_dir_fd_member_name != no_such_member; then
77 AC_DEFINE_UNQUOTED(DIR_FD_MEMBER_NAME,
78 $gl_cv_sys_dir_fd_member_name,
79 [the name of the file descriptor member of DIR])
81 AH_VERBATIM(DIR_TO_FD,
82 [#ifdef DIR_FD_MEMBER_NAME
83 # define DIR_TO_FD(Dir_p) ((Dir_p)->DIR_FD_MEMBER_NAME)
85 # define DIR_TO_FD(Dir_p) -1