rename(2)                                               rename(2)



     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.

          [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.




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     rename(2)                                               rename(2)



          [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]     path points outside the process's allocated
                       address space.

          [EINVAL]     from is a parent directory of to.

     SEE ALSO
          open(2).



































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