NAME
rename - change the name of a file

SYNOPSIS
rename(from, to)
const char *from, *to;

DESCRIPTION
Rename causes the link named from to be renamed as to. If to
exists, then 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.

Rename guarantees that 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.

CAVEAT
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",
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. Hard links to directories should be
replaced by symbolic links by the system administrator.

RETURN VALUE
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
Rename will fail and neither of the argument files will be affected
if any of the following are true:

[EINVAL] Either pathname contains a character with the high-
order bit set.

[ENAMETOOLONG] A component of either pathname exceeded 255
characters, or the entire length of either path name
exceeded 1023 characters.

[ENOENT] A component of the from path does not exist, or a
path prefix of to does not exist.

[EACCES] A component of either path prefix denies search
permission.

[EACCES] The requested link requires writing in a directory
with a mode that denies write permission.

[EPERM] The directory containing from is marked sticky, and
neither the containing directory nor from are owned
by the effective user ID.

[EPERM] 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.

[ELOOP] Too many symbolic links were encountered in
translating either pathname.

[ENOTDIR] A component of either path prefix is not a
directory.

[ENOTDIR] From is a directory, but to is not a directory.

[EISDIR] To is a directory, but from is not a directory.

[EXDEV] 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.

[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.

[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.

[EIO] An I/O error occurred while making or updating a
directory entry.

[EROFS] The requested link requires writing in a directory
on a read-only file system.

[EFAULT] Path points outside the process’s allocated address
space.

[EINVAL] From is a parent directory of to, or an attempt is
made to rename "." or "..".

[ENOTEMPTY] To is a directory and is not empty.

SEE ALSO
open(2)