3 dnl Find out how to get the file descriptor associated with an open DIR*.
5 # Copyright (C) 2001, 2002, 2003, 2004 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 dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57.
15 AC_REQUIRE([AC_PROG_CPP])
16 AC_REQUIRE([AC_PROG_EGREP])
22 #else /* not HAVE_DIRENT_H */
23 # define dirent direct
25 # include <sys/ndir.h>
26 # endif /* HAVE_SYS_NDIR_H */
29 # endif /* HAVE_SYS_DIR_H */
32 # endif /* HAVE_NDIR_H */
33 #endif /* HAVE_DIRENT_H */
36 AC_CHECK_DECLS([dirfd], , , $dirfd_headers)
38 AC_CACHE_CHECK([whether dirfd is a macro],
39 gl_cv_func_dirfd_macro,
40 [AC_EGREP_CPP([dirent_header_defines_dirfd], [$dirfd_headers
42 dirent_header_defines_dirfd
44 gl_cv_func_dirfd_macro=yes,
45 gl_cv_func_dirfd_macro=no)])
47 # Use the replacement only if we have no function, macro,
48 # or declaration with that name.
49 if test $ac_cv_func_dirfd,$ac_cv_have_decl_dirfd,$gl_cv_func_dirfd_macro \
51 AC_REPLACE_FUNCS([dirfd])
53 [how to get the file descriptor associated with an open DIR*],
54 gl_cv_sys_dir_fd_member_name,
56 dirfd_save_CFLAGS=$CFLAGS
57 for ac_expr in d_fd dd_fd; do
59 CFLAGS="$CFLAGS -DDIR_FD_MEMBER_NAME=$ac_expr"
63 [DIR *dir_p = opendir("."); (void) dir_p->DIR_FD_MEMBER_NAME;],
66 CFLAGS=$dirfd_save_CFLAGS
67 test "$dir_fd_found" = yes && break
69 test "$dir_fd_found" = yes || ac_expr=no_such_member
71 gl_cv_sys_dir_fd_member_name=$ac_expr
74 if test $gl_cv_sys_dir_fd_member_name != no_such_member; then
75 AC_DEFINE_UNQUOTED(DIR_FD_MEMBER_NAME,
76 $gl_cv_sys_dir_fd_member_name,
77 [the name of the file descriptor member of DIR])
79 AH_VERBATIM(DIR_TO_FD,
80 [#ifdef DIR_FD_MEMBER_NAME
81 # define DIR_TO_FD(Dir_p) ((Dir_p)->DIR_FD_MEMBER_NAME)
83 # define DIR_TO_FD(Dir_p) -1