RENAME(2)
NAME
rename − change the name of a file
USAGE
rename(from, to)
char *from, *to;
DESCRIPTION
Rename causes the link named from to be renamed to. If a file to existed before the call, it is removed. Both from and to must be of the same type (that is, both directories or both non-directories), and they 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.
NOTES
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” (e.g., “a/foo”) being a hard link to directory “b”, and an entry in directory “b” (e.g., “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 while trying to lock both directories for modification. Hard links to directories should be replaced with symbolic links by the system administrator.
RETURN VALUE
A zero 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:
[ENOTDIR] A component of either path prefix is not a directory.
[ENOENT] A component of either path prefix does not exist.
[EACCES] A component of either path prefix denies search permission.
[ENOENT] The file named by from does not exist.
[EPERM] The file named by from is a directory and the effective user ID is not super-user.
[EXDEV] The link named by to and the file named by from are on different logical devices (i.e., file systems). Note that this error code will not be returned if the implementation permits cross-device links.
[EACCES] The requested link requires writing in a directory with a mode that denies write permission.
[EROFS] The requested link requires writing in a directory on a read-only file system.
[EFAULT] Path points outside the process’ allocated address space.
[EINVAL] From is a parent directory of to.