2 dnl Copyright (C) 2009, 2010 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
7 AC_DEFUN([gl_FUNC_UNLINK],
9 AC_REQUIRE([gl_AC_DOS])
10 AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
11 AC_REQUIRE([AC_CANONICAL_HOST])
12 dnl Detect FreeBSD 7.2, AIX 7.1, Solaris 9 bug.
13 AC_CACHE_CHECK([whether unlink honors trailing slashes],
14 [gl_cv_func_unlink_honors_slashes],
16 # Assume that if we have lstat, we can also check symlinks.
17 if test $ac_cv_func_lstat = yes; then
18 ln -s conftest.file conftest.lnk
24 ]], [[if (!unlink ("conftest.file/") || errno != ENOTDIR) return 1;
26 if (!unlink ("conftest.lnk/") || errno != ENOTDIR) return 2;
29 [gl_cv_func_unlink_honors_slashes=yes],
30 [gl_cv_func_unlink_honors_slashes=no],
31 [gl_cv_func_unlink_honors_slashes="guessing no"])
32 rm -f conftest.file conftest.lnk])
33 dnl Detect MacOS X 10.5.6 bug: On read-write HFS mounts, unlink("..") or
34 dnl unlink("../..") succeeds without doing anything.
35 AC_CACHE_CHECK([whether unlink of a parent directory fails as it should],
36 [gl_cv_func_unlink_parent_fails],
39 dnl Try to unlink a subdirectory of /tmp, because /tmp is usually on a
40 dnl HFS mount on MacOS X. Use a subdirectory, owned by the current
41 dnl user, because otherwise unlink() may fail due to permissions
42 dnl reasons, and because when running as root we don't want to risk
43 dnl destroying the entire /tmp.
45 # Use the mktemp program if available. If not available, hide the error
47 tmp=`(umask 077 && mktemp -d /tmp/gtXXXXXX) 2>/dev/null` &&
48 test -n "$tmp" && test -d "$tmp"
51 # Use a simple mkdir command. It is guaranteed to fail if the directory
52 # already exists. $RANDOM is bash specific and expands to empty in shells
53 # other than bash, ksh and zsh. Its use does not increase security;
54 # rather, it minimizes the probability of failure in a very cluttered /tmp
57 (umask 077 && mkdir "$tmp")
60 GL_SUBDIR_FOR_UNLINK="$tmp/subdir"
61 export GL_SUBDIR_FOR_UNLINK
68 if (chdir (getenv ("GL_SUBDIR_FOR_UNLINK")) != 0)
70 return unlink ("..") == 0;
73 [gl_cv_func_unlink_parent_fails=yes],
74 [gl_cv_func_unlink_parent_fails=no],
75 [gl_cv_func_unlink_parent_fails="guessing no"])
76 unset GL_SUBDIR_FOR_UNLINK
79 gl_cv_func_unlink_parent_fails="guessing no"
83 gl_cv_func_unlink_parent_fails="guessing yes"
87 case "$gl_cv_func_unlink_parent_fails" in
89 AC_DEFINE([UNLINK_PARENT_BUG], [1],
90 [Define to 1 if unlink() on a parent directory may succeed])
93 if test "$gl_cv_func_unlink_honors_slashes" != yes \
94 || { case "$gl_cv_func_unlink_parent_fails" in