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@(#)rename.2 8.1 (Berkeley) 6/4/93
.Dd February 14, 2025 .Dt RENAME 2 .Os .Sh NAME .Nm rename , .Nm renameat .Nd change the name of a file .Sh LIBRARY .Lb libc .Sh SYNOPSIS n stdio.h .Ft int .Fn rename "const char *from" "const char *to" n unistd.h .Ft int .Fn renameat "int fromfd" "const char *from" "int tofd" "const char *to" .Sh DESCRIPTION .Fn rename causes the link named .Fa from to be renamed as .Fa to . If .Fa to exists, it is first removed. Both .Fa from and .Fa to must be of the same type (that is, both directories or both non-directories), and must reside on the same file system.
p .Fn rename guarantees that an instance of .Fa to will always exist, even if the system should crash in the middle of the operation.
p If the final component of .Fa from is a symbolic link, the symbolic link is renamed, not the file or directory to which it points.
p If both .Fa from and .Fa to refer to the same name in the same directory, .Fn rename returns successfully and performs no other action.
p
.Fn renameat
works the same way as
.Fn rename
except if
.Fa from
(resp.
.Fa to )
is relative.
In that case, it is looked up from a directory whose file
descriptor was passed as
.Fa fromfd
(resp.
.Fa tofd ) .
Search permission is required on the directories named by
.Fa fromfd
and
.Fa tofd .
(These alternatives await a decision about the semantics of O_SEARCH)
Search permission is required on the directories named by
.Fa fromfd
and
.Fa tofd
unless they were opened with the
.Dv O_SEARCH
flag.
- or -
The directories named by
.Fa fromfd
and
.Fa tofd
must have been opened with the
.Dv O_SEARCH
flag.
.Fa fromfd
or
.Fa tofd
can be set to
.Dv AT_FDCWD
in order to specify the current directory.
.Sh RETURN VALUES
.Rv -std rename renameat
.Sh ERRORS
.Fn rename
and
.Fn renameat
will fail and neither of the argument files will be
affected if:
l -tag -width Er t Bq Er EACCES A component of either path prefix denies search permission, or
the requested link requires writing in a directory with a mode
that denies write permission.
t Bq Er EBUSY .Fa from
or
.Fa to
is the mount point for a mounted file system.
t Bq Er 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.
t Bq Er EFAULT .Fa from
or
.Fa to
points outside the process's allocated address space.
t Bq Er EINVAL .Fa from
is a parent directory of
.Fa to ,
or an attempt is made to rename
.Ql .
or
.Ql .. .
t Bq Er EIO An I/O error occurred while making or updating a directory entry.
t Bq Er EISDIR .Fa to
is a directory, but
.Fa from
is not a directory.
t Bq Er ELOOP Too many symbolic links were encountered in translating either pathname.
t Bq Er ENAMETOOLONG A component of a pathname exceeded
rq Dv NAME_MAX characters, or an entire path name exceeded
rq Dv PATH_MAX characters.
t Bq Er ENOENT A component of the
.Fa from
path does not exist,
or a path prefix of
.Fa to
does not exist.
t Bq Er 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.
t Bq Er ENOTDIR A component of either path prefix is not a directory, or
.Fa from
is a directory, but
.Fa to
is not a directory.
t Bq Er ENOTEMPTY .Fa to
is a directory and is not empty.
t Bq Er EPERM The directory containing
.Fa from
is marked sticky,
and neither the containing directory nor
.Fa from
are owned by the effective user ID.
Or the
.Fa to
file exists,
the directory containing
.Fa to
is marked sticky,
and neither the containing directory nor
.Fa to
are owned by the effective user ID.
t Bq Er EROFS The requested link requires writing in a directory on a read-only file
system.
t Bq Er EXDEV The link named by
.Fa to
and the file named by
.Fa from
are on different logical devices (file systems).
Note that this error code will not be returned if the implementation
permits cross-device links.
.El
p In addition, .Fn renameat will fail if: l -tag -width Er t Bq Er EBADF .Fa from or .Fa to does not specify an absolute path and .Fa fromfd or .Fa tofd , respectively, is neither .Dv AT_FDCWD nor a valid file descriptor open for reading or searching. t Bq Er ENOTDIR .Fa from or .Fa to is not an absolute path and .Fa fromfd or .Fa tofd , respectively, is a file descriptor associated with a non-directory file. .El .Sh SEE ALSO .Xr open 2 , .Xr symlink 7 .Sh STANDARDS The .Fn rename function deviates from the semantics defined in .St -p1003.1-90 , which specifies that if both .Fa from and .Fa to .Em link to the same existing file, .Fn rename shall return successfully and performs no further action, whereas this implementation will remove the file specified by .Fa from unless both .Fa from and .Fa to are the same name in the same directory.
p To retain conformance, a compatibility interface is provided by the .Lb libposix which is also be brought into scope if any of the .Dv _POSIX_SOURCE , .Dv _POSIX_C_SOURCE or .Dv _XOPEN_SOURCE preprocessor symbols are defined at compile-time: the .Fn rename function conforms to .St -p1003.1-90 and .St -xpg4.2 . .Fn renameat conforms to .St -p1003.1-2008 . .Sh BUGS The system can deadlock if a loop in the file system graph is present. This loop takes the form of an entry in directory .Ql Pa a , say .Ql Pa a/foo , being a hard link to directory .Ql Pa b , and an entry in directory .Ql Pa b , say .Ql Pa b/bar , being a hard link to directory .Ql Pa a . When such a loop exists and two separate processes attempt to perform .Ql rename a/foo b/bar and .Ql 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.
Indexes created Wed Sep 24 05:09:52 GMT 2025