2 # Determine whether we need the chown wrapper.
4 dnl Copyright (C) 1997-2001, 2003-2005, 2007, 2009
5 dnl Free 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([gl_UNISTD_H_DEFAULTS])
20 AC_REQUIRE([AC_TYPE_UID_T])
21 AC_REQUIRE([AC_FUNC_CHOWN])
22 AC_REQUIRE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK])
24 if test $ac_cv_func_chown_works = no; then
25 AC_DEFINE([CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE], [1],
26 [Define if chown is not POSIX compliant regarding IDs of -1.])
29 # If chown has either of the above problems, then we need the wrapper.
30 if test $ac_cv_func_chown_works$gl_cv_func_chown_follows_symlink = yesyes; then
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([[
54 char const *dangling_symlink = "conftest.dangle";
56 unlink (dangling_symlink);
57 if (symlink ("conftest.no-such", dangling_symlink))
60 /* Exit successfully on a conforming system,
61 i.e., where chown must fail with ENOENT. */
62 exit ( ! (chown (dangling_symlink, getuid (), getgid ()) != 0
66 [gl_cv_func_chown_follows_symlink=yes],
67 [gl_cv_func_chown_follows_symlink=no],
68 [gl_cv_func_chown_follows_symlink=yes]
73 if test $gl_cv_func_chown_follows_symlink = no; then
74 AC_DEFINE([CHOWN_MODIFIES_SYMLINK], [1],
75 [Define if chown modifies symlinks.])
79 # Prerequisites of lib/chown.c.
80 AC_DEFUN([gl_PREREQ_CHOWN],
82 AC_CHECK_FUNC([fchown], , [AC_LIBOBJ([fchown-stub])])