mirror of https://github.com/mkerrisk/man-pages
126 lines
3.9 KiB
Groff
126 lines
3.9 KiB
Groff
.\" Hey Emacs! This file is -*- nroff -*- source.
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.\"
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.\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
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.\"
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.\" Permission is granted to make and distribute verbatim copies of this
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.\" manual provided the copyright notice and this permission notice are
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.\" preserved on all copies.
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.\"
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.\" Permission is granted to copy and distribute modified versions of this
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.\" manual under the conditions for verbatim copying, provided that the
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.\" entire resulting derived work is distributed under the terms of a
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.\" permission notice identical to this one.
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.\"
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.\" Since the Linux kernel and libraries are constantly changing, this
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.\" manual page may be incorrect or out-of-date. The author(s) assume no
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.\" responsibility for errors or omissions, or for damages resulting from
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.\" the use of the information contained herein. The author(s) may not
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.\" have taken the same level of care in the production of this manual,
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.\" which is licensed free of charge, as they might when working
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.\" professionally.
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.\"
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.\" Formatted or processed versions of this manual, if unaccompanied by
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.\" the source, must acknowledge the copyright and authors of this work.
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.\"
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.\" Modified by Michael Haardt <michael@moria.de>
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.\" Modified 1993-07-21 by Rik Faith <faith@cs.unc.edu>
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.\" Modified 1994-08-21 by Michael Chastain <mec@shell.portal.com>
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.\" Modified 1996-06-13 by aeb
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.\" Modified 1996-11-06 by Eric S. Raymond <esr@thyrsus.com>
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.\" Modified 1997-08-21 by Joseph S. Myers <jsm28@cam.ac.uk>
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.\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
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.\"
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.TH CHROOT 2 2004-06-23 "Linux 2.6.7" "Linux Programmer's Manual"
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.SH NAME
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chroot \- change root directory
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.SH SYNOPSIS
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.B #include <unistd.h>
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.sp
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.BI "int chroot(const char *" path );
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.SH DESCRIPTION
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.BR chroot ()
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changes the root directory to that specified in
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.IR path .
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This directory will be used for pathnames beginning with /.
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The root directory is inherited by all children of the current process.
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Only a privileged process (Linux: one with the
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.B CAP_SYS_CHROOT
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capability) may call
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.BR chroot (2).
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This call changes an ingredient in the pathname resolution process
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and does nothing else.
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This call does not change the current working directory,
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so that after the call `.' can be outside the tree rooted at `/'.
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In particular, the superuser can escape from a `chroot jail'
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by doing `mkdir foo; chroot foo; cd ..'.
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This call does not close open file descriptors, and such file
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descriptors may allow access to files outside the chroot tree.
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.SH "RETURN VALUE"
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On success, zero is returned.
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On error, \-1 is returned, and
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.I errno
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is set appropriately.
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.SH ERRORS
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Depending on the file system, other errors can be returned.
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The more general errors are listed below:
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.TP
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.B EACCES
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Search permission is denied on a component of the path prefix.
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(See also
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.BR path_resolution (2).)
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.\" Also search permission is required on the final component,
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.\" maybe just to guarantee that it is a directory?
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.TP
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.B EFAULT
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.I path
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points outside your accessible address space.
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.TP
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.B EIO
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An I/O error occurred.
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.TP
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.B ELOOP
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Too many symbolic links were encountered in resolving
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.IR path .
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.TP
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.B ENAMETOOLONG
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.I path
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is too long.
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.TP
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.B ENOENT
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The file does not exist.
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.TP
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.B ENOMEM
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Insufficient kernel memory was available.
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.TP
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.B ENOTDIR
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A component of
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.I path
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is not a directory.
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.TP
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.B EPERM
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The caller has insufficient privilege.
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.SH "CONFORMING TO"
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SVr4, 4.4BSD, SUSv2 (marked LEGACY).
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This function is not part of POSIX.1-2001.
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.\" SVr4 documents additional EINTR, ENOLINK and EMULTIHOP error conditions.
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.\" X/OPEN does not document EIO, ENOMEM or EFAULT error conditions.
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.SH NOTES
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A child process created via
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.BR fork (2)
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inherits its parent's root directory.
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The root directory is left unchanged by
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.BR execve (2).
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FreeBSD has a stronger
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.BR jail ()
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system call.
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.\" FIXME -- eventually say something about containers,
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.\" virtual servers, etc.?
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.SH "SEE ALSO"
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.BR chdir (2),
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.BR path_resolution (2)
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