mirror of
https://git.savannah.gnu.org/git/gnulib.git
synced 2025-08-16 01:22:18 +03:00
e176ee0b5d
* lib/unlinkat.c: unlinkat() has the same bug as unlink() on Mac OS X 10.10, where it ignores paths with a trailing "..", so handle in the same manner. * m4/unlinkat.m4: Comment on this Darwin issue. * doc/posix-functions/unlink.texi: Update the latest version where the issue was seen. * doc/posix-functions/unlinkat.texi: Mention this issue. Fixes a test failure in test-unlinkat.c.
55 lines
2.1 KiB
Plaintext
55 lines
2.1 KiB
Plaintext
@node unlinkat
|
|
@section @code{unlinkat}
|
|
@findex unlinkat
|
|
|
|
POSIX specification:@* @url{http://www.opengroup.org/onlinepubs/9699919799/functions/unlinkat.html}
|
|
|
|
Gnulib module: unlinkat
|
|
|
|
Portability problems fixed by Gnulib:
|
|
@itemize
|
|
@item
|
|
This function is missing on some platforms:
|
|
glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8,
|
|
AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin 1.5.x, mingw, MSVC 9, Interix 3.5, BeOS.
|
|
But the replacement function is not safe to be used in libraries and is not multithread-safe.
|
|
@item
|
|
On Mac OS X 10.10, in a writable HFS mount, @code{unlinkat(fd, "..", 0)} succeeds
|
|
without doing anything.
|
|
@item
|
|
Some systems mistakenly succeed on @code{unlinkat(fd,"file/",flag)}:
|
|
GNU/Hurd, Solaris 9.
|
|
@item
|
|
Some platforms declare this function in @code{fcntl.h} instead of
|
|
@code{unistd.h}:
|
|
Cygwin 1.7.1.
|
|
@end itemize
|
|
|
|
Portability problems not fixed by Gnulib:
|
|
@itemize
|
|
@item
|
|
When @code{unlinkat(fd,name,AT_REMOVEDIR)} fails because the specified
|
|
directory is not empty, the @code{errno} value is system dependent.
|
|
@item
|
|
POSIX requires that @code{unlinkdir(fd,"link-to-empty/",AT_REMOVEDIR)}
|
|
remove @file{empty} and leave @file{link-to-empty} as a dangling
|
|
symlink. This is counter-intuitive, so some systems fail with
|
|
@code{ENOTDIR} instead:
|
|
glibc
|
|
@item
|
|
Some systems allow a superuser to unlink directories, even though this
|
|
can cause file system corruption. The error given if a process is not
|
|
permitted to unlink directories varies across implementations; it is
|
|
not always the POSIX value of @code{EPERM}. Meanwhile, if a process
|
|
has the ability to unlink directories, POSIX requires that
|
|
@code{unlinkat(fd,"symlink-to-dir/",0)} remove @file{dir} and leave
|
|
@file{symlink-to-dir} dangling; this behavior is counter-intuitive.
|
|
The gnulib module unlinkdir can help determine whether code must be
|
|
cautious of unlinking directories.
|
|
@item
|
|
Removing an open file is non-portable: On Unix this allows the programs that
|
|
have the file already open to continue working with it; the file's storage
|
|
is only freed when the no process has the file open any more. On Windows,
|
|
the attempt to remove an open file fails.
|
|
@end itemize
|