1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
# serial 35
# Determine whether we need the chown wrapper.
dnl Copyright (C) 1997-2001, 2003-2005, 2007, 2009-2023 Free Software
dnl Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
# chown should accept arguments of -1 for uid and gid, and it should
# dereference symlinks. If it doesn't, arrange to use the replacement
# function.
# From Jim Meyering.
# This is taken from the following Autoconf patch:
# https://git.savannah.gnu.org/gitweb/?p=autoconf.git;a=commitdiff;h=7fbb553727ed7e0e689a17594b58559ecf3ea6e9
AC_DEFUN([AC_FUNC_CHOWN],
[
AC_REQUIRE([AC_TYPE_UID_T])dnl
AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles
AC_CHECK_HEADERS([unistd.h])
AC_CACHE_CHECK([for working chown],
[ac_cv_func_chown_works],
[AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[AC_INCLUDES_DEFAULT
[#include <fcntl.h>
]GL_MDA_DEFINES],
[[
char *f = "conftest.chown";
struct stat before, after;
if (creat (f, 0600) < 0)
return 1;
if (stat (f, &before) < 0)
return 1;
if (chown (f, (uid_t) -1, (gid_t) -1) == -1)
return 1;
if (stat (f, &after) < 0)
return 1;
return ! (before.st_uid == after.st_uid && before.st_gid == after.st_gid);
]])
],
[ac_cv_func_chown_works=yes],
[ac_cv_func_chown_works=no],
[case "$host_os" in # ((
# Guess yes on Linux systems.
linux-* | linux) ac_cv_func_chown_works="guessing yes" ;;
# Guess yes on glibc systems.
*-gnu* | gnu*) ac_cv_func_chown_works="guessing yes" ;;
# Guess no on native Windows.
mingw*) ac_cv_func_chown_works="guessing no" ;;
# If we don't know, obey --enable-cross-guesses.
*) ac_cv_func_chown_works="$gl_cross_guess_normal" ;;
esac
])
rm -f conftest.chown
])
case "$ac_cv_func_chown_works" in
*yes)
AC_DEFINE([HAVE_CHOWN], [1],
[Define to 1 if your system has a working `chown' function.])
;;
esac
])# AC_FUNC_CHOWN
AC_DEFUN_ONCE([gl_FUNC_CHOWN],
[
AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
AC_REQUIRE([AC_TYPE_UID_T])
AC_REQUIRE([AC_FUNC_CHOWN])
AC_REQUIRE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
AC_CHECK_FUNCS_ONCE([chown fchown])
dnl mingw lacks chown altogether.
if test $ac_cv_func_chown = no; then
HAVE_CHOWN=0
else
dnl Some old systems treated chown like lchown.
case "$gl_cv_func_chown_follows_symlink" in
*yes) ;;
*) REPLACE_CHOWN=1 ;;
esac
dnl Some old systems tried to use uid/gid -1 literally.
case "$ac_cv_func_chown_works" in
*no)
AC_DEFINE([CHOWN_FAILS_TO_HONOR_ID_OF_NEGATIVE_ONE], [1],
[Define if chown is not POSIX compliant regarding IDs of -1.])
REPLACE_CHOWN=1
;;
esac
dnl Solaris 9 ignores trailing slash.
dnl FreeBSD 7.2 mishandles trailing slash on symlinks.
dnl Likewise for AIX 7.1.
AC_CACHE_CHECK([whether chown honors trailing slash],
[gl_cv_func_chown_slash_works],
[touch conftest.file && rm -f conftest.link
AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
]GL_MDA_DEFINES],
[[if (symlink ("conftest.file", "conftest.link")) return 1;
if (chown ("conftest.link/", getuid (), getgid ()) == 0) return 2;
]])],
[gl_cv_func_chown_slash_works=yes],
[gl_cv_func_chown_slash_works=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu*) gl_cv_func_chown_slash_works="guessing yes" ;;
# Guess yes on musl systems.
*-musl*) gl_cv_func_chown_slash_works="guessing yes" ;;
# If we don't know, obey --enable-cross-guesses.
*) gl_cv_func_chown_slash_works="$gl_cross_guess_normal" ;;
esac
])
rm -f conftest.link conftest.file])
case "$gl_cv_func_chown_slash_works" in
*yes) ;;
*)
AC_DEFINE([CHOWN_TRAILING_SLASH_BUG], [1],
[Define to 1 if chown mishandles trailing slash.])
REPLACE_CHOWN=1
;;
esac
dnl OpenBSD fails to update ctime if ownership does not change.
AC_CACHE_CHECK([whether chown always updates ctime],
[gl_cv_func_chown_ctime_works],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([[
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
]GL_MDA_DEFINES],
[[struct stat st1, st2;
if (close (creat ("conftest.file", 0600))) return 1;
if (stat ("conftest.file", &st1)) return 2;
sleep (1);
if (chown ("conftest.file", st1.st_uid, st1.st_gid)) return 3;
if (stat ("conftest.file", &st2)) return 4;
if (st2.st_ctime <= st1.st_ctime) return 5;
]])],
[gl_cv_func_chown_ctime_works=yes],
[gl_cv_func_chown_ctime_works=no],
[case "$host_os" in
# Guess yes on glibc systems.
*-gnu*) gl_cv_func_chown_ctime_works="guessing yes" ;;
# Guess yes on musl systems.
*-musl*) gl_cv_func_chown_ctime_works="guessing yes" ;;
# If we don't know, obey --enable-cross-guesses.
*) gl_cv_func_chown_ctime_works="$gl_cross_guess_normal" ;;
esac
])
rm -f conftest.file])
case "$gl_cv_func_chown_ctime_works" in
*yes) ;;
*)
AC_DEFINE([CHOWN_CHANGE_TIME_BUG], [1], [Define to 1 if chown fails
to change ctime when at least one argument was not -1.])
REPLACE_CHOWN=1
;;
esac
fi
])
# Determine whether chown follows symlinks (it should).
AC_DEFUN_ONCE([gl_FUNC_CHOWN_FOLLOWS_SYMLINK],
[
AC_CACHE_CHECK(
[whether chown dereferences symlinks],
[gl_cv_func_chown_follows_symlink],
[
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
]GL_MDA_DEFINES[
int
main ()
{
int result = 0;
char const *dangling_symlink = "conftest.dangle";
unlink (dangling_symlink);
if (symlink ("conftest.no-such", dangling_symlink))
abort ();
/* Exit successfully on a conforming system,
i.e., where chown must fail with ENOENT. */
if (chown (dangling_symlink, getuid (), getgid ()) == 0)
result |= 1;
if (errno != ENOENT)
result |= 2;
return result;
}
]])],
[gl_cv_func_chown_follows_symlink=yes],
[gl_cv_func_chown_follows_symlink=no],
[gl_cv_func_chown_follows_symlink="guessing yes"]
)
]
)
case "$gl_cv_func_chown_follows_symlink" in
*yes) ;;
*)
AC_DEFINE([CHOWN_MODIFIES_SYMLINK], [1],
[Define if chown modifies symlinks.])
;;
esac
])
|
