2 # Determine whether we need the chown wrapper.
4 dnl Copyright (C) 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005 Free
5 dnl Software Foundation, Inc.
7 dnl This file is free software; the Free Software Foundation
8 dnl gives unlimited permission to copy and/or distribute it,
9 dnl with or without modifications, as long as this notice is preserved.
11 # chown should accept arguments of -1 for uid and gid, and it should
12 # dereference symlinks. If it doesn't, arrange to use the replacement
17 AC_DEFUN([gl_FUNC_CHOWN],
19 AC_REQUIRE([AC_TYPE_UID_T])
20 AC_REQUIRE([AC_FUNC_CHOWN])
21 AC_REQUIRE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK])
23 if test $ac_cv_func_chown_works = yes; then
24 AC_DEFINE(CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE, 1,
25 [Define if chown is not POSIX compliant regarding IDs of -1.])
28 # If chown has either of the above problems, then we need the wrapper.
29 if test $ac_cv_func_chown_works$gl_cv_func_chown_follows_symlink = yesyes; then
33 AC_DEFINE(chown, rpl_chown,
34 [Define to rpl_chown if the replacement function should be used.])
39 # Determine whether chown follows symlinks (it should).
40 AC_DEFUN([gl_FUNC_CHOWN_FOLLOWS_SYMLINK],
43 [whether chown(2) dereferences symlinks],
44 gl_cv_func_chown_follows_symlink,
46 AC_RUN_IFELSE([AC_LANG_SOURCE([[
56 char const *dangling_symlink = "conftest.dangle";
58 unlink (dangling_symlink);
59 if (symlink ("conftest.no-such", dangling_symlink))
62 /* Exit successfully on a conforming system,
63 i.e., where chown must fail with ENOENT. */
64 exit ( ! (chown (dangling_symlink, getuid (), getgid ()) != 0
68 [gl_cv_func_chown_follows_symlink=yes],
69 [gl_cv_func_chown_follows_symlink=no],
70 [gl_cv_func_chown_follows_symlink=yes]
75 if test $gl_cv_func_chown_follows_symlink = no; then
76 AC_DEFINE(CHOWN_MODIFIES_SYMLINK, 1,
77 [Define if chown modifies symlinks.])
81 # Prerequisites of lib/chown.c.
82 AC_DEFUN([gl_PREREQ_CHOWN],
84 AC_CHECK_HEADERS_ONCE(unistd.h fcntl.h)
85 AC_CHECK_FUNC([fchown], , [AC_LIBOBJ(fchown-stub)])