1 .\" Copyright (c) 1983, 1991, 1993
2 .\" The Regents of the University of California. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice, this list of conditions and the following disclaimer.
9 .\" 2. Redistributions in binary form must reproduce the above copyright
10 .\" notice, this list of conditions and the following disclaimer in the
11 .\" documentation and/or other materials provided with the distribution.
12 .\" 3. All advertising materials mentioning features or use of this software
13 .\" must display the following acknowledgement:
14 .\" This product includes software developed by the University of
15 .\" California, Berkeley and its contributors.
16 .\" 4. Neither the name of the University nor the names of its contributors
17 .\" may be used to endorse or promote products derived from this software
18 .\" without specific prior written permission.
20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 .\" @(#)chroot.2 8.1 (Berkeley) 6/4/93
40 .Nd change root directory
46 .Fn chroot "const char *dirname"
51 is the address of the pathname of a directory, terminated by an ASCII NUL.
56 to become the root directory,
57 that is, the starting point for path searches of pathnames
61 In order for a directory to become the root directory
62 a process must have execute (search) access for that directory.
64 It should be noted that
66 has no effect on the process's current directory.
68 This call is restricted to the super-user.
70 Depending on the setting of the
71 .Ql kern.chroot_allow_open_directories
72 sysctl variable, open filedescriptors which reference directories
78 .Ql kern.chroot_allow_open_directories
83 if there are any directories open.
86 .Ql kern.chroot_allow_open_directories
87 is set to one (the default),
91 if there are any directories open and the
92 process is already subject to the
97 .Ql kern.chroot_allow_open_directories
98 will bypass the check for open directories
100 Upon successful completion, a value of 0 is returned.
102 a value of -1 is returned and
104 is set to indicate an error.
109 will fail and the root directory will be unchanged if:
112 A component of the path name is not a directory.
114 The effective user ID is not the super-user, or one or more
115 filedescriptors are open directories.
116 .It Bq Er ENAMETOOLONG
117 A component of a pathname exceeded 255 characters,
118 or an entire path name exceeded 1023 characters.
120 The named directory does not exist.
122 Search permission is denied for any component of the path name.
124 Too many symbolic links were encountered in translating the pathname.
129 points outside the process's allocated address space.
131 An I/O error occurred while reading from or writing to the file system.
139 system call appeared in
142 If the process is able to change its working directory to the target
143 directory, but another access control check fails (such as a check for
144 open directories, or a MAC check), it is possible that this system
145 call may return an error, with the working directory of the process