.\"
.\" @(#)rename.2 8.1 (Berkeley) 6/4/93
.\"
-.Dd June 4, 1993
+.Dd September 18, 2008
.Dt RENAME 2
.Os BSD 4.2
.Sh NAME
-.Nm rename
+.Nm rename ,
+.Nm renameat ,
+.Nm renamex_np ,
+.Nm renameatx_np
.Nd change the name of a file
.Sh SYNOPSIS
.Fd #include <stdio.h>
.Fa "const char *old"
.Fa "const char *new"
.Fc
+.Ft int
+.Fn renameat "int fromfd" "const char *from" "int tofd" "const char *to"
+.Ft int
+.Fn renamex_np "const char *from" "const char *to" "unsigned int flags"
+.Ft int
+.Fn renameatx_np "int fromfd" "const char *from" "int tofd" "const char *to" "unsigned int flags"
.Sh DESCRIPTION
The
.Fn rename
is a symbolic link,
the symbolic link is renamed,
not the file or directory to which it points.
-.Sh CAVEAT
+.Pp
+The
+.Fn renameat
+system call is equivalent to
+.Fn rename
+except in the case where either
+.Fa from
+or
+.Fa to
+specifies a relative path.
+If
+.Fa from
+is a relative path, the file to be renamed is located
+relative to the directory associated with the file descriptor
+.Fa fromfd
+instead of the current working directory.
+If the
+.Fa to
+is a relative path, the same happens only relative to the directory associated
+with
+.Fa tofd .
+If the
+.Fn renameat
+is passed the special value
+.Dv AT_FDCWD
+in the
+.Fa fromfd
+or
+.Fa tofd
+parameter, the current working directory is used in the determination
+of the file for the respective path parameter.
+.Pp
+The
+.Fn renamex_np
+and
+.Fn renameatx_np
+system calls are similar to their counterparts except that they take a
+.Fa flags
+argument.
+Values for
+.Fa flags
+are constructed with below bits set:
+.Bl -tag -offset indent
+.It Dv RENAME_SWAP
+On file systems that support it (see
+.Xr getattrlist 2
+.Dv VOL_CAP_INT_RENAME_SWAP Ns ),
+it will cause the source and target to be atomically swapped. Source and target need not be of
+the same type, i.e. it is possible to swap a file with a directory.
+EINVAL is returned in case of bitwise-inclusive OR with
+.Dv RENAME_EXCL .
+.It Dv RENAME_EXCL
+On file systems that support it (see
+.Xr getattrlist 2
+.Dv VOL_CAP_INT_RENAME_EXCL Ns ),
+it will cause
+.Dv EEXIST
+to be returned if the destination already exists. EINVAL is returned in case of bitwise-inclusive OR with
+.Dv RENAME_SWAP .
+.El
+.Sh CAVEATS
The system can deadlock if a loop is present in the file system graph.
This loop takes the form of an entry in directory
.Ql Pa a ,
It is recommended that any hard links to directories in an underlying
filesystem should be replaced by symbolic links by the system administrator
to avoid the possibility of deadlocks.
+.Pp
+Moving or renaming a file or directory into a directory with inheritable ACLs does not result in ACLs being set on the file or directory. Use
+.Xr acl 3
+in conjunction with
+.Fn rename
+to set ACLs on the file or directory.
.Sh RETURN VALUES
A 0 value is returned if the operation succeeds, otherwise
.Fn rename
.Fa new ,
new/.., or old/..) whose modes disallow this.
.\" ===========
+.It Bq Er EACCES
+.Fa old
+is a directory and it, or some descendent in the namespace, is open
+and the file system format does does not support renaming a directory
+with open descendents (see
+.Xr getattrlist 2
+.Dv VOL_CAP_INT_RENAME_OPENFAIL Ns ).
+.\" ===========
.It Bq Er 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.
.\" ===========
+.It Bq Er EEXIST
+.Fa flags
+has
+.Dv RENAME_EXCL
+set but
+.Fa new
+already exists.
+.\" ===========
.It Bq Er EFAULT
.Em Path
points outside the process's allocated address space.
.Ql \&.
or
.Ql \&.. .
+If
+.Dv RENAME_SWAP
+is used, then
+.Dv EINVAL
+will also be returned if
+.Fa new
+is a parent directory of
+.Fa old .
+If both RENAME_SWAP and RENAME_EXCL bits are set in
+.Fa flags ,
+then
+.Dv EINVAL
+will be returned.
+.\" ===========
+.It Bq Er EINVAL
+.Fa flags
+has an invalid value.
.\" ===========
.It Bq Er EIO
An I/O error occurs while making or updating a directory entry.
.Fa new
does not exist.
.\" ===========
+.It Bq Er ENOENT
+.Fa flags
+has
+.Dv RENAME_SWAP
+set but
+.Fa new
+does not exist.
+.\" ===========
.It Bq Er 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
.Fa New
is a directory and is not empty.
.\" ===========
+.It Bq Er ENOTSUP
+.Fa flags
+has a value that is not supported by the file system.
+.\" ===========
.It Bq Er EPERM
The directory containing
.Fa old
Note that this error code will not be returned
if the implementation permits cross-device links.
.El
+.Pp
+The
+.Fn renameat
+and
+.Fn renameatx_np
+calls may also fail with:
+.Bl -tag -width Er
+.It Bq Er EBADF
+The
+.Fa from
+argument does not specify an absolute path and the
+.Fa fromfd
+argument is neither
+.Dv AT_FDCWD
+nor a valid file descriptor open for searching, or the
+.Fa to
+argument does not specify an absolute path and the
+.Fa tofd
+argument is neither
+.Dv AT_FDCWD
+nor a valid file descriptor open for searching.
+.It Bq Er ENOTDIR
+The
+.Fa from
+argument is not an absolute path and
+.Fa fromfd
+is neither
+.Dv AT_FDCWD
+nor a file descriptor associated with a directory, or the
+.Fa to
+argument is not an absolute path and
+.Fa tofd
+is neither
+.Dv AT_FDCWD
+nor a file descriptor associated with a directory.
+.El
.Sh CONFORMANCE
The restriction on renaming a directory whose permissions disallow writing
is based on the fact that UFS directories contain a ".." entry.
.Fn rename
function conforms to
.St -p1003.1-88 .
+The
+.Fn renameat
+system call is expected to conform to POSIX.1-2008 .
projects / apple / xnu.git / blobdiff