ultrix man page for rename

rename(2)							System Calls Manual							 rename(2)

Name
       rename - change the name of a file

Syntax
       rename(from, to)
       char *from, *to;

Description
       The system call causes the link named from to be renamed 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 nondirectories) and must reside on the same file system.

       The system call guarantees that an instance of to will always exist, even if the system should crash in the middle of the operation.

Return Values
       A zero (0) value is returned if the operation succeeds. Otherwise returns -1, and the global variable errno indicates the  reason  for  the
       failure.

Restrictions
       The system can deadlock if a loop in the file system graph is present.and two processes issue the call at the same time.  For example, sup-
       pose a directory, contains a file, Suppose that file is hard-linked to a directory, and the directory contains a file, If is hard-linked to
       a loop exists.  Now suppose one process issues the following call:
       rename (dirname/filename secondir/secondfile)
       At the same time, another process issues the following call:
       rename (secondir/secondfile dirname/filename)
       In this case, the system can deadlock.  The system administrator should replace hard links to directories with symbolic links.

Diagnostics
       The system call fails and neither of the argument files are affected under the following conditions:

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

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

       [ENOENT]       Either from or to points to an empty string and the environment defined is POSIX or SYSTEM_FIVE.

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

       [EPERM]	      The  to  file exists, the directory containing from is marked sticky, and neither the containing directory nor the to direc-
		      tory is owned by the effective user ID.

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

       [EXDEV]	      The  link named by to and the file named by from are on different logical devices (file systems).  Note that this error code
		      is not 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]       The path points outside the process's allocated address space.

       [EINVAL]       The from is a parent directory of to, or an attempt is made to rename dot (.) or dot-dot (..).

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

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

       [ENOTDIR]      The from is a directory, but to is not a directory.

       [EISDIR]       The to is a directory, but from is not a directory.

       [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.

       [ENOTEMPTY]    The to is a directory and is not empty.

       [EBUSY]	      The directory named by from or to is a mount point.

See Also
       open(2)

																	 rename(2)