— change the name of a
char *from, const char
fromfd, const char
*from, int tofd,
const char *to);
function causes the link named from to be renamed as
to. If to exists, it is first
removed. Both from and to must
be of the same type (that is, both directories or both non-directories), and
must reside on the same file system.
guarantees that if to already exists, an instance of
to will always exist, even if the system should crash
in the middle of the operation.
If the final component of from is a symbolic link, the symbolic link is renamed, not the file or directory to which it points.
function is equivalent to
rename() except that where
from or to specifies a relative
path, the directory entry names used are resolved relative to the
directories associated with file descriptors fromfd or
tofd (respectively) instead of the current working
is passed the special value
AT_FDCWD (defined in
<fcntl.h>) in the
fromfd or tofd parameter, the
current working directory is used for resolving the respective
from or to argument.
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.
renameat() will fail and neither of the argument
files will be affected if:
- A component of a pathname exceeded
NAME_MAXcharacters, or an entire pathname (including the terminating NUL) exceeded
- A component of the from path does not exist, or a path prefix of to does not exist.
- A component of either path prefix denies search permission.
- The requested change requires writing in a directory that denies write permission.
- The from argument is a directory and denies write permission.
- The directory containing from is marked sticky, and neither the containing directory nor from are owned by the effective user ID.
- The to file exists, the directory containing to is marked sticky, and neither the containing directory nor to are owned by the effective user ID.
- Too many symbolic links were encountered in translating either pathname.
- The link count on the source file or destination directory is at the maximum. A rename cannot be completed under these conditions.
- A component of either path prefix is not a directory.
- from is a directory, but to is not a directory.
- to is a directory, but from is not a directory.
- The link named by to and the file named by from are on different logical devices (file systems). Note that this error code will not be returned if the implementation permits cross-device links.
- The directory in which the entry for the new name is being placed cannot be extended because there is no space left on the file system containing the directory.
- The directory in which the entry for the new name is being placed cannot be extended because the user's quota of disk blocks on the file system containing the directory has been exhausted.
- An I/O error occurred while making or updating a directory entry.
- The requested link requires writing in a directory on a read-only file system.
- from or to points outside the process's allocated address space.
- from is a parent directory of
to, or an attempt is made to rename
.’ or ‘
- to is a directory and is not empty.
renameat() will fail if:
- The from or to argument
specifies a relative path and the fromfd or
tofd argument, respectively, is neither
AT_FDCWDnor a valid file descriptor.
- The from or to argument specifies a relative path and the fromfd or tofd argument, respectively, is a valid file descriptor but it does not reference a directory.
- The from or to argument specifies a relative path but search permission is denied for the directory which the fromfd or tofd file descriptor, respectively, references.
mv(1), open(2), symlink(7)
renameat() functions conform to
IEEE Std 1003.1-2008 (“POSIX.1”).
renameat() function appeared in
The system can deadlock if a loop in the file system graph is
present. This loop takes the form of an entry in directory
‘a/foo’, being a hard link to
directory ‘b’, and an entry in
directory ‘b’, say
‘b/bar’, being a hard link to
directory ‘a’. When such a loop exists
and two separate processes attempt to perform
rename a/foo b/bar’ and
rename b/bar a/foo’, respectively,
the system may deadlock attempting to lock both directories for
modification. Hard links to directories should be replaced by symbolic links
by the system administrator.