RENAME(2)                DOMAIN/IX SYS5                 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 with name
     to.  If a file named to existed before the call to rename,
     it is removed.  Both from and to must be objects of the same
     type (that is, both directories or both non-directories),
     and both 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 opera-
     tion.

NOTES
     The system can deadlock if a "circular link" is present.  A
     circular link occurs when an entry in directory "a" (e.g.,
     "a/foo") is a hard link to directory "b", and an entry in
     directory "b" (e.g., "b/bar") is a hard link to directory
     "a".  When such a relationship 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.  To
     prevent this problem, a system administrator should replace
     all hard links to directories with symbolic ones.

RETURN VALUE
     A successful call returns zero.  A failed call returns -1
     and sets errno as indicated below.

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 direc-
               tory.

     [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



Printed 12/4/86                                          RENAME-1

RENAME(2)                DOMAIN/IX SYS5                 RENAME(2)



               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 sys-
               tems).  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.

RELATED INFORMATION
     open(2)
































RENAME-2                                          Printed 12/4/86