[apple/xnu.git] / bsd / man / man2 / rename.2

.\"	$NetBSD: rename.2,v 1.7 1995/02/27 12:36:15 cgd Exp $
.\"
.\" Copyright (c) 1983, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)rename.2	8.1 (Berkeley) 6/4/93
.\"
.Dd June 4, 1993
.Dt RENAME 2
.Os BSD 4.2
.Sh NAME
.Nm rename
.Nd change the name of a file
.Sh SYNOPSIS
.Fd #include <stdio.h>
.Ft int
.Fn rename "const char *from" "const char *to"
.Sh DESCRIPTION
.Fn Rename
causes the link named
.Fa from
to be renamed as
.Fa to .
If 
.Fa to
exists, it is first removed.
Both 
.Fa from
and
.Fa to
must be of the same type (that is, both directories or both
non-directories), and must reside on the same file system.
.Pp
.Fn Rename
guarantees that an instance of
.Fa to
will always exist, even if the system should crash in
the middle of the operation.
.Pp
If the final component of
.Fa from
is a symbolic link,
the symbolic link is renamed,
not the file or directory to which it points.
.Sh 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
.Ql Pa a ,
say
.Ql Pa a/foo ,
being a hard link to directory
.Ql Pa b ,
and an entry in
directory
.Ql Pa b ,
say
.Ql Pa b/bar ,
being a hard link
to directory
.Ql Pa a .
When such a loop exists and two separate processes attempt to
perform
.Ql rename a/foo b/bar
and
.Ql 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.
.Sh RETURN VALUES
A 0 value is returned if the operation succeeds, otherwise
.Fn rename
returns -1 and the global variable 
.Va errno
indicates the reason for the failure.
.Sh ERRORS
.Fn Rename
will fail and neither of the argument files will be
affected if:
.Bl -tag -width Er
.It Bq Er ENAMETOOLONG
A component of a pathname exceeded 
.Dv {NAME_MAX}
characters, or an entire path name exceeded 
.Dv {PATH_MAX}
characters.
.It Bq Er ENOENT
A component of the
.Fa from
path does not exist,
or a path prefix of
.Fa to
does not exist.
.It Bq Er EACCES
A component of either path prefix denies search permission.
.It Bq Er EACCES
The requested link requires writing in a directory with a mode
that denies write permission.
.It Bq Er EPERM
The directory containing
.Fa from
is marked sticky,
and neither the containing directory nor
.Fa from
are owned by the effective user ID.
.It Bq Er EPERM
The
.Fa to
file exists,
the directory containing
.Fa to
is marked sticky,
and neither the containing directory nor
.Fa to
are owned by the effective user ID.
.It Bq Er ELOOP
Too many symbolic links were encountered in translating either pathname.
.It Bq Er ENOTDIR
A component of either path prefix is not a directory.
.It Bq Er ENOTDIR
.Fa from
is a directory, but
.Fa to
is not a directory.
.It Bq Er EISDIR
.Fa to
is a directory, but
.Fa from
is not a directory.
.It Bq Er EXDEV
The link named by
.Fa to
and the file named by
.Fa from
are on different logical devices (file systems).  Note that this error
code will not be returned if the implementation permits cross-device
links.
.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
system containing the directory.
.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 EIO
An I/O error occurred while making or updating a directory entry.
.It Bq Er EROFS
The requested link requires writing in a directory on a read-only file
system.
.It Bq Er EFAULT
.Em Path
points outside the process's allocated address space.
.It Bq Er EINVAL
.Fa From
is a parent directory of
.Fa to ,
or an attempt is made to rename
.Ql \&.
or
.Ql \&.. .
.It Bq Er ENOTEMPTY
.Fa To
is a directory and is not empty.
.El
.Sh SEE ALSO
.Xr open 2
.Xr symlink 7
.Sh STANDARDS
The
.Fn rename
function conforms to 
.St -p1003.1-88 .
Commit	Line	Data
9bccf70c A	1	.\" $NetBSD: rename.2,v 1.7 1995/02/27 12:36:15 cgd Exp $
	2	.\"
	3	.\" Copyright (c) 1983, 1991, 1993
	4	.\" The Regents of the University of California. All rights reserved.
	5	.\"
	6	.\" Redistribution and use in source and binary forms, with or without
	7	.\" modification, are permitted provided that the following conditions
	8	.\" are met:
	9	.\" 1. Redistributions of source code must retain the above copyright
	10	.\" notice, this list of conditions and the following disclaimer.
	11	.\" 2. Redistributions in binary form must reproduce the above copyright
	12	.\" notice, this list of conditions and the following disclaimer in the
	13	.\" documentation and/or other materials provided with the distribution.
	14	.\" 3. All advertising materials mentioning features or use of this software
	15	.\" must display the following acknowledgement:
	16	.\" This product includes software developed by the University of
	17	.\" California, Berkeley and its contributors.
	18	.\" 4. Neither the name of the University nor the names of its contributors
	19	.\" may be used to endorse or promote products derived from this software
	20	.\" without specific prior written permission.
	21	.\"
	22	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	23	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	26	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	27	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	28	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	29	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	30	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	31	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	32	.\" SUCH DAMAGE.
	33	.\"
	34	.\" @(#)rename.2 8.1 (Berkeley) 6/4/93
	35	.\"
	36	.Dd June 4, 1993
	37	.Dt RENAME 2
	38	.Os BSD 4.2
	39	.Sh NAME
	40	.Nm rename
	41	.Nd change the name of a file
	42	.Sh SYNOPSIS
	43	.Fd #include <stdio.h>
	44	.Ft int
	45	.Fn rename "const char from" "const char to"
	46	.Sh DESCRIPTION
	47	.Fn Rename
	48	causes the link named
	49	.Fa from
	50	to be renamed as
	51	.Fa to .
	52	If
	53	.Fa to
	54	exists, it is first removed.
	55	Both
	56	.Fa from
	57	and
	58	.Fa to
	59	must be of the same type (that is, both directories or both
	60	non-directories), and must reside on the same file system.
	61	.Pp
	62	.Fn Rename
	63	guarantees that an instance of
	64	.Fa to
65	will always exist, even if the system should crash in
66	the middle of the operation.
67	.Pp
68	If the final component of
69	.Fa from
70	is a symbolic link,
71	the symbolic link is renamed,
72	not the file or directory to which it points.
73	.Sh CAVEAT
74	The system can deadlock if a loop in the file system graph is present.
75	This loop takes the form of an entry in directory
76	.Ql Pa a ,
77	say
78	.Ql Pa a/foo ,
79	being a hard link to directory
80	.Ql Pa b ,
81	and an entry in
82	directory
83	.Ql Pa b ,
84	say
85	.Ql Pa b/bar ,
86	being a hard link
87	to directory
88	.Ql Pa a .
89	When such a loop exists and two separate processes attempt to
90	perform
91	.Ql rename a/foo b/bar
92	and
93	.Ql rename b/bar a/foo ,
94	respectively,
95	the system may deadlock attempting to lock
96	both directories for modification.
97	Hard links to directories should be
98	replaced by symbolic links by the system administrator.
99	.Sh RETURN VALUES
100	A 0 value is returned if the operation succeeds, otherwise
101	.Fn rename
102	returns -1 and the global variable
103	.Va errno
104	indicates the reason for the failure.
105	.Sh ERRORS
106	.Fn Rename
107	will fail and neither of the argument files will be
108	affected if:
109	.Bl -tag -width Er
110	.It Bq Er ENAMETOOLONG
111	A component of a pathname exceeded
112	.Dv {NAME_MAX}
113	characters, or an entire path name exceeded
114	.Dv {PATH_MAX}
115	characters.
116	.It Bq Er ENOENT
117	A component of the
118	.Fa from
119	path does not exist,
120	or a path prefix of
121	.Fa to
122	does not exist.
123	.It Bq Er EACCES
124	A component of either path prefix denies search permission.
125	.It Bq Er EACCES
126	The requested link requires writing in a directory with a mode
127	that denies write permission.
128	.It Bq Er EPERM
129	The directory containing
130	.Fa from
131	is marked sticky,
132	and neither the containing directory nor
133	.Fa from
134	are owned by the effective user ID.
135	.It Bq Er EPERM
136	The
137	.Fa to
138	file exists,
139	the directory containing
140	.Fa to
141	is marked sticky,
142	and neither the containing directory nor
143	.Fa to
144	are owned by the effective user ID.
145	.It Bq Er ELOOP
146	Too many symbolic links were encountered in translating either pathname.
147	.It Bq Er ENOTDIR
148	A component of either path prefix is not a directory.
149	.It Bq Er ENOTDIR
150	.Fa from
151	is a directory, but
152	.Fa to
153	is not a directory.
154	.It Bq Er EISDIR
155	.Fa to
156	is a directory, but
157	.Fa from
158	is not a directory.
159	.It Bq Er EXDEV
160	The link named by
161	.Fa to
162	and the file named by
163	.Fa from
164	are on different logical devices (file systems). Note that this error
165	code will not be returned if the implementation permits cross-device
166	links.
167	.It Bq Er ENOSPC
168	The directory in which the entry for the new name is being placed
169	cannot be extended because there is no space left on the file
170	system containing the directory.
171	.It Bq Er EDQUOT
172	The directory in which the entry for the new name
173	is being placed cannot be extended because the
174	user's quota of disk blocks on the file system
175	containing the directory has been exhausted.
176	.It Bq Er EIO
177	An I/O error occurred while making or updating a directory entry.
178	.It Bq Er EROFS
179	The requested link requires writing in a directory on a read-only file
180	system.
181	.It Bq Er EFAULT
182	.Em Path
183	points outside the process's allocated address space.
184	.It Bq Er EINVAL
185	.Fa From
186	is a parent directory of
187	.Fa to ,
188	or an attempt is made to rename
189	.Ql \&.
190	or
191	.Ql \&.. .
192	.It Bq Er ENOTEMPTY
193	.Fa To
194	is a directory and is not empty.
195	.El
196	.Sh SEE ALSO
197	.Xr open 2
198	.Xr symlink 7
199	.Sh STANDARDS
200	The
201	.Fn rename
202	function conforms to
203	.St -p1003.1-88 .