man2/chroot.2

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   3 .\" Copyright (c) 1992 Drew Eckhardt (drew@cs.colorado.edu), March 28, 1992
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  25 .\" Modified by Michael Haardt <michael@moria.de>
  26 .\" Modified 1993-07-21 by Rik Faith <faith@cs.unc.edu>
  27 .\" Modified 1994-08-21 by Michael Chastain <mec@shell.portal.com>
  28 .\" Modified 1996-06-13 by aeb
  29 .\" Modified 1996-11-06 by Eric S. Raymond <esr@thyrsus.com>
  30 .\" Modified 1997-08-21 by Joseph S. Myers <jsm28@cam.ac.uk>
  31 .\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
  32 .\"
  33 .TH CHROOT 2 2004-06-23 "Linux 2.6.7" "Linux Programmer's Manual"
  34 .SH NAME
  35 chroot \- change root directory
  36 .SH SYNOPSIS
  37 .B #include <unistd.h>
  38 .sp
  39 .BI "int chroot(const char *" path );
  40 .SH DESCRIPTION
  41 .BR chroot ()
  42 changes the root directory to that specified in
  43 .IR path .
  44 This directory will be used for path names beginning with /.  The root
  45 directory is inherited by all children of the current process.
  46
  47 Only a privileged process (Linux: one with the
  48 .B CAP_SYS_CHROOT
  49 capability) may call
  50 .BR chroot (2).
  51
  52 This call changes an ingredient in the pathname resolution process
  53 and does nothing else.
  54
  55 This call does not change the current working directory,
  56 so that after the call `.' can be outside the tree rooted at `/'.
  57 In particular, the superuser can escape from a `chroot jail'
  58 by doing `mkdir foo; chroot foo; cd ..'.
  59
  60 This call does not close open file descriptors, and such file
  61 descriptors may allow access to files outside the chroot tree.
  62
  63 .SH "RETURN VALUE"
  64 On success, zero is returned.  On error, \-1 is returned, and
  65 .I errno
  66 is set appropriately.
  67 .SH ERRORS
  68 Depending on the file system, other errors can be returned.  The more
  69 general errors are listed below:
  70 .TP
  71 .B EACCES
  72 Search permission is denied on a component of the path prefix.
  73 (See also
  74 .BR path_resolution (2).)
  75 .\" Also search permission is required on the final component,
  76 .\" maybe just to guarantee that it is a directory?
  77 .TP
  78 .B EFAULT
  79 .I path
  80 points outside your accessible address space.
  81 .TP
  82 .B EIO
  83 An I/O error occurred.
  84 .TP
  85 .B ELOOP
  86 Too many symbolic links were encountered in resolving
  87 .IR path .
  88 .TP
  89 .B ENAMETOOLONG
  90 .I path
  91 is too long.
  92 .TP
  93 .B ENOENT
  94 The file does not exist.
  95 .TP
  96 .B ENOMEM
  97 Insufficient kernel memory was available.
  98 .TP
  99 .B ENOTDIR
 100 A component of
 101 .I path
 102 is not a directory.
 103 .TP
 104 .B EPERM
 105 The caller has insufficient privilege.
 106 .SH "CONFORMING TO"
 107 SVr4, SVID, 4.4BSD, X/OPEN.  This function is not part of POSIX.1.
 108 SVr4 documents additional EINTR, ENOLINK and EMULTIHOP error conditions.
 109 X/OPEN does not document EIO, ENOMEM or EFAULT error conditions.
 110 This interface is marked as legacy by X/OPEN.
 111 .SH NOTES
 112 FreeBSD has a stronger
 113 .BR jail ()
 114 system call.
 115 .SH "SEE ALSO"
 116 .BR chdir (2),
 117 .BR path_resolution (2)