NAME
rename
, renameat
,
renamex_np
, renameatx_np
— change the name of a
file
SYNOPSIS
#include
<stdio.h>
int
rename
(const char *old,
const char *new);
int
renameat
(int
fromfd, const char
*from, int tofd,
const char *to);
int
renamex_np
(const
char *from, const char
*to, unsigned int
flags);
int
renameatx_np
(int
fromfd, const char
*from, int tofd,
const char *to,
unsigned int flags);
DESCRIPTION
The
rename
()
system call causes the link named old to be renamed as
new. If new exists, it is first
removed. Both old and new must
be of the same type (that is, both must be either directories or
non-directories) and must reside on the same file system.
The
rename
()
system call guarantees that an instance of new will
always exist, even if the system should crash in the middle of the
operation.
If the final component of old is a symbolic link, the symbolic link is renamed, not the file or directory to which it points.
The
renameat
()
system call is equivalent to rename
() except in the
case where either from or to
specifies a relative path. If from is a relative path,
the file to be renamed is located relative to the directory associated with
the file descriptor fromfd instead of the current
working directory. If the to is a relative path, the
same happens only relative to the directory associated with
tofd. If the renameat
() is
passed the special value AT_FDCWD
in the
fromfd or tofd parameter, the
current working directory is used in the determination of the file for the
respective path parameter.
The
renamex_np
()
and
renameatx_np
()
system calls are similar to their counterparts except that they take a
flags argument. Values for flags
are constructed with below bits set:
RENAME_SWAP
- On file systems that support it (see
getattrlist(2)
VOL_CAP_INT_RENAME_SWAP
), it will cause the source and target to be atomically swapped. Source and target need not be of the same type, i.e. it is possible to swap a file with a directory. EINVAL is returned in case of bitwise-inclusive OR withRENAME_EXCL
. RENAME_EXCL
- On file systems that support it (see
getattrlist(2)
VOL_CAP_INT_RENAME_EXCL
), it will causeEEXIST
to be returned if the destination already exists. EINVAL is returned in case of bitwise-inclusive OR withRENAME_SWAP
. RENAME_NOFOLLOW_ANY
- If any symbolic links are encountered during pathname resolution, an error is returned.
CAVEATS
The system can deadlock if a loop is present in the file system
graph. This loop takes the form of an entry in directory
‘a
’, say
‘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.
Whether or not hard links to directories are supported is specific to the underlying filesystem implementation.
It is recommended that any hard links to directories in an underlying filesystem should be replaced by symbolic links by the system administrator to avoid the possibility of deadlocks.
Moving or renaming a file or directory into a directory with
inheritable ACLs does not result in ACLs being set on the file or directory.
Use acl(3) in
conjunction with rename
() to set ACLs on the file or
directory.
RETURN VALUES
A 0 value is returned if the operation succeeds, otherwise
rename
() returns -1 and the global variable
errno indicates the reason for the failure.
ERRORS
The rename
() system call will fail and
neither of the argument files will be affected if:
- [
EACCES
] - A component of either path prefix denies search permission.
- [
EACCES
] - The requested operation requires writing in a directory (e.g., new, new/.., or old/..) whose modes disallow this.
- [
EACCES
] - old is a directory and it, or some descendent in the
namespace, is open and the file system format does does not support
renaming a directory with open descendents (see
getattrlist(2)
VOL_CAP_INT_RENAME_OPENFAIL
). - [
EDQUOT
] - 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.
- [
EEXIST
] - flags has
RENAME_EXCL
set but new already exists. - [
EFAULT
] - Path points outside the process's allocated address space.
- [
EINVAL
] - Old is a parent directory of
new, or an attempt is made to rename
‘
.
’ or ‘..
’. IfRENAME_SWAP
is used, thenEINVAL
will also be returned if new is a parent directory of old. If both RENAME_SWAP and RENAME_EXCL bits are set in flags, thenEINVAL
will be returned. - [
EINVAL
] - flags has an invalid value.
- [
EIO
] - An I/O error occurs while making or updating a directory entry.
- [
EISDIR
] - new is a directory, but old is not a directory.
- [
ELOOP
] - Too many symbolic links are encountered in translating either pathname. This is taken to be indicative of a looping symbolic link.
- [
ELOOP
] - If RENAME_NOFOLLOW_ANY was passed and a symbolic link was encountered in translating either pathname.
- [
ENAMETOOLONG
] - A component of a pathname exceeds
{NAME_MAX}
characters, or an entire path name exceeds{PATH_MAX}
characters. - [
ENOENT
] - A component of the old path does not exist, or a path prefix of new does not exist.
- [
ENOENT
] - flags has
RENAME_SWAP
set but new does not exist. - [
ENOSPC
] - 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.
- [
ENOTDIR
] - A component of either path prefix is not a directory.
- [
ENOTDIR
] - old is a directory, but new is not a directory.
- [
ENOTEMPTY
] - New is a directory and is not empty.
- [
ENOTSUP
] - flags has a value that is not supported by the file system.
- [
EPERM
] - The directory containing old is marked sticky, and neither the containing directory nor old are owned by the effective user ID.
- [
EPERM
] - The new file exists, the directory containing new is marked sticky, and neither the containing directory nor new are owned by the effective user ID.
- [
EROFS
] - The requested link requires writing in a directory on a read-only file system.
- [
EXDEV
] - The link named by new and the file named by old are on different logical devices (file systems). Note that this error code will not be returned if the implementation permits cross-device links.
- [
EDEADLK
] - A component of either pathname refers to a “dataless” directory that requires materialization and the I/O policy of the current thread or process disallows dataless directory materialization (see getiopolicy_np(3)).
- [
EDEADLK
] - The from pathname refers to a “dataless” file or directory that must be materialized before being moved to its new location and the I/O policy of the current thread or process disallows file or directory materialization (see getiopolicy_np(3)).
The renameat
() and
renameatx_np
() calls may also fail with:
- [
EBADF
] - The from argument does not specify an absolute path
and the fromfd argument is neither
AT_FDCWD
nor a valid file descriptor open for searching, or the to argument does not specify an absolute path and the tofd argument is neitherAT_FDCWD
nor a valid file descriptor open for searching. - [
ENOTDIR
] - The from argument is not an absolute path and
fromfd is neither
AT_FDCWD
nor a file descriptor associated with a directory, or the to argument is not an absolute path and tofd is neitherAT_FDCWD
nor a file descriptor associated with a directory.
CONFORMANCE
The restriction on renaming a directory whose permissions disallow writing is based on the fact that UFS directories contain a ".." entry. If renaming a directory would move it to another parent directory, this entry needs to be changed.
This restriction has been generalized to disallow renaming of any write-disabled directory, even when this would not require a change to the ".." entry. For consistency, HFS+ directories emulate this behavior.
SEE ALSO
STANDARDS
The rename
() function conforms to
IEEE Std 1003.1-1988 (“POSIX.1”). The
renameat
() system call is expected to conform to
POSIX.1-2008 .