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#serial 6 |
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|
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dnl Find out how to get the file descriptor associated with an open DIR*. |
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dnl From Jim Meyering |
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|
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AC_DEFUN([UTILS_FUNC_DIRFD], |
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[ |
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dnl Work around a bug of AC_EGREP_CPP in autoconf-2.57. |
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AC_REQUIRE([AC_PROG_CPP]) |
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AC_REQUIRE([AC_PROG_EGREP]) |
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|
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AC_HEADER_DIRENT |
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dirfd_headers=' |
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#if HAVE_DIRENT_H |
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# include <dirent.h> |
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#else /* not HAVE_DIRENT_H */ |
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# define dirent direct |
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# if HAVE_SYS_NDIR_H |
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# include <sys/ndir.h> |
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# endif /* HAVE_SYS_NDIR_H */ |
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# if HAVE_SYS_DIR_H |
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# include <sys/dir.h> |
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# endif /* HAVE_SYS_DIR_H */ |
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# if HAVE_NDIR_H |
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# include <ndir.h> |
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# endif /* HAVE_NDIR_H */ |
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#endif /* HAVE_DIRENT_H */ |
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' |
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AC_CHECK_FUNCS(dirfd) |
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AC_CHECK_DECLS([dirfd], , , $dirfd_headers) |
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|
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AC_CACHE_CHECK([whether dirfd is a macro], |
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jm_cv_func_dirfd_macro, |
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[AC_EGREP_CPP([dirent_header_defines_dirfd], [$dirfd_headers |
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#ifdef dirfd |
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dirent_header_defines_dirfd |
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#endif], |
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jm_cv_func_dirfd_macro=yes, |
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jm_cv_func_dirfd_macro=no)]) |
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|
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# Use the replacement only if we have no function, macro, |
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# or declaration with that name. |
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if test $ac_cv_func_dirfd,$ac_cv_have_decl_dirfd,$jm_cv_func_dirfd_macro \ |
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= no,no,no; then |
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AC_REPLACE_FUNCS([dirfd]) |
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AC_CACHE_CHECK( |
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[how to get the file descriptor associated with an open DIR*], |
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gl_cv_sys_dir_fd_member_name, |
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[ |
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dirfd_save_CFLAGS=$CFLAGS |
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for ac_expr in d_fd dd_fd; do |
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|
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CFLAGS="$CFLAGS -DDIR_FD_MEMBER_NAME=$ac_expr" |
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AC_TRY_COMPILE( |
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[$dirfd_headers |
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], |
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[DIR *dir_p = opendir("."); (void) dir_p->DIR_FD_MEMBER_NAME;], |
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dir_fd_found=yes |
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) |
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CFLAGS=$dirfd_save_CFLAGS |
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test "$dir_fd_found" = yes && break |
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done |
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test "$dir_fd_found" = yes || ac_expr=no_such_member |
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|
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gl_cv_sys_dir_fd_member_name=$ac_expr |
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] |
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) |
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if test $gl_cv_sys_dir_fd_member_name != no_such_member; then |
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AC_DEFINE_UNQUOTED(DIR_FD_MEMBER_NAME, |
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$gl_cv_sys_dir_fd_member_name, |
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[the name of the file descriptor member of DIR]) |
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fi |
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AH_VERBATIM(DIR_TO_FD, |
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[#ifdef DIR_FD_MEMBER_NAME |
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# define DIR_TO_FD(Dir_p) ((Dir_p)->DIR_FD_MEMBER_NAME) |
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#else |
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# define DIR_TO_FD(Dir_p) -1 |
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#endif |
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] |
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) |
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fi |
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]) |