NAME

rename − change the name of a file

SYNOPSIS

rename(from, to)
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. 

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:

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

[ENOTDIR] An attempt was made to rename a directory to an existing non-directory file, or a non-directory file to an existing 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. 

[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. 

[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] From or to points outside the process’s allocated address space. 

[EINVAL] From is a parent directory of to.

[ENOENT] The path name is too long. 

[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. 

[EIO] An I/O error occurred while reading from or writing to the file system. 

SEE ALSO

open(2)

4BSD