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_ONCE([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])
23 AC_CHECK_FUNCS_ONCE([chown fchown])
25 if test $ac_cv_func_chown = no; then
29 if test $gl_cv_func_chown_follows_symlink = no; then
33 if test $ac_cv_func_chown_works = no; then
34 AC_DEFINE([CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE], [1],
35 [Define if chown is not POSIX compliant regarding IDs of -1.])
39 AC_CACHE_CHECK([whether chown honors trailing slash],
40 [gl_cv_func_chown_slash_works],
41 [touch conftest.file && rm -f conftest.link
42 AC_RUN_IFELSE([AC_LANG_PROGRAM([[
46 ]], [[ if (symlink ("conftest.file", "conftest.link")) return 1;
47 if (chown ("conftest.link/", getuid (), getgid ()) == 0) return 2;
49 [gl_cv_func_chown_slash_works=yes],
50 [gl_cv_func_chown_slash_works=no],
51 [gl_cv_func_chown_slash_works="guessing no"])
52 rm -f conftest.link conftest.file])
53 if test "$gl_cv_func_chown_slash_works" != yes; then
54 AC_DEFINE([CHOWN_TRAILING_SLASH_BUG], [1],
55 [Define if chown mishandles trailing slash.])
59 if test $REPLACE_CHOWN = 1 && test $ac_cv_func_fchown = no; then
60 AC_LIBOBJ([fchown-stub])
65 # Determine whether chown follows symlinks (it should).
66 AC_DEFUN_ONCE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK],
69 [whether chown dereferences symlinks],
70 [gl_cv_func_chown_follows_symlink],
72 AC_RUN_IFELSE([AC_LANG_SOURCE([[
80 char const *dangling_symlink = "conftest.dangle";
82 unlink (dangling_symlink);
83 if (symlink ("conftest.no-such", dangling_symlink))
86 /* Exit successfully on a conforming system,
87 i.e., where chown must fail with ENOENT. */
88 exit ( ! (chown (dangling_symlink, getuid (), getgid ()) != 0
92 [gl_cv_func_chown_follows_symlink=yes],
93 [gl_cv_func_chown_follows_symlink=no],
94 [gl_cv_func_chown_follows_symlink=yes]
99 if test $gl_cv_func_chown_follows_symlink = no; then
100 AC_DEFINE([CHOWN_MODIFIES_SYMLINK], [1],
101 [Define if chown modifies symlinks.])