]> git.saurik.com Git - apple/xnu.git/blame_incremental - bsd/man/man2/chroot.2
xnu-7195.101.1.tar.gz
[apple/xnu.git] / bsd / man / man2 / chroot.2
... / ...
CommitLineData
1.\" $NetBSD: chroot.2,v 1.7 1995/02/27 12:32:12 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.\" @(#)chroot.2 8.1 (Berkeley) 6/4/93
35.\"
36.Dd June 4, 1993
37.Dt CHROOT 2
38.Os BSD 4.2
39.Sh NAME
40.Nm chroot
41.Nd change root directory
42.Sh SYNOPSIS
43.Fd #include <unistd.h>
44.Ft int
45.Fn chroot "const char *dirname"
46.Sh DESCRIPTION
47.Fa Dirname
48is the address of the pathname of a directory, terminated by an ASCII NUL.
49.Fn chroot
50causes
51.Fa dirname
52to become the root directory,
53that is, the starting point for path searches of pathnames
54beginning with
55.Ql / .
56.Pp
57In order for a directory to become the root directory
58a process must have execute (search) access for that directory.
59.Pp
60If the program is not currently running with an altered root directory,
61it should be noted that
62.Fn chroot
63has no effect on the process's current directory.
64.Pp
65If the program is already running with an altered root directory, the
66process's current directory is changed to the same new root directory.
67This prevents the current directory from being further up the directory
68tree than the altered root directory.
69.Pp
70This call is restricted to the super-user.
71.Sh RETURN VALUES
72Upon successful completion, a value of 0 is returned. Otherwise,
73a value of -1 is returned and
74.Va errno
75is set to indicate an error.
76.Sh ERRORS
77.Fn chroot
78will fail and the root directory will be unchanged if:
79.Bl -tag -width Er
80.It Bq Er ENOTDIR
81A component of the path name is not a directory.
82.It Bq Er ENAMETOOLONG
83A component of a pathname exceeded
84.Dv {NAME_MAX}
85characters, or an entire path name exceeded
86.Dv {PATH_MAX}
87characters.
88.It Bq Er ENOENT
89The named directory does not exist.
90.It Bq Er EACCES
91Search permission is denied for any component of the path name.
92.It Bq Er ELOOP
93Too many symbolic links were encountered in translating the pathname.
94.It Bq Er EFAULT
95.Fa Path
96points outside the process's allocated address space.
97.It Bq Er EIO
98An I/O error occurred while reading from or writing to the file system.
99.El
100.Sh SEE ALSO
101.Xr chdir 2
102.Sh WARNINGS
103There are ways for a root process to escape from the chroot jail.
104.Sh HISTORY
105The
106.Fn chroot
107function call appeared in
108.Bx 4.2 .