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chroot(2) [suse man page]

CHROOT(2)						     Linux Programmer's Manual							 CHROOT(2)

NAME
chroot - change root directory SYNOPSIS
#include <unistd.h> int chroot(const char *path); DESCRIPTION
chroot() changes the root directory of the calling process to that specified in path. This directory will be used for pathnames beginning with /. The root directory is inherited by all children of the calling process. Only a privileged process (Linux: one with the CAP_SYS_CHROOT capability) may call chroot(). This call changes an ingredient in the pathname resolution process and does nothing else. This call does not change the current working directory, so that after the call '.' can be outside the tree rooted at '/'. In particular, the superuser can escape from a "chroot jail" by doing: mkdir foo; chroot foo; cd .. This call does not close open file descriptors, and such file descriptors may allow access to files outside the chroot tree. RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is set appropriately. ERRORS
Depending on the file system, other errors can be returned. The more general errors are listed below: EACCES Search permission is denied on a component of the path prefix. (See also path_resolution(7).) EFAULT path points outside your accessible address space. EIO An I/O error occurred. ELOOP Too many symbolic links were encountered in resolving path. ENAMETOOLONG path is too long. ENOENT The file does not exist. ENOMEM Insufficient kernel memory was available. ENOTDIR A component of path is not a directory. EPERM The caller has insufficient privilege. CONFORMING TO
SVr4, 4.4BSD, SUSv2 (marked LEGACY). This function is not part of POSIX.1-2001. NOTES
A child process created via fork(2) inherits its parent's root directory. The root directory is left unchanged by execve(2). FreeBSD has a stronger jail() system call. SEE ALSO
chdir(2), path_resolution(7) COLOPHON
This page is part of release 3.25 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2008-06-23 CHROOT(2)

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CHROOT(2)						      BSD System Calls Manual							 CHROOT(2)

NAME
chroot -- change root directory SYNOPSIS
#include <unistd.h> int chroot(const char *dirname); DESCRIPTION
Dirname is the address of the pathname of a directory, terminated by an ASCII NUL. Chroot() causes dirname to become the root directory, that is, the starting point for path searches of pathnames beginning with '/'. In order for a directory to become the root directory a process must have execute (search) access for that directory. If the program is not currently running with an altered root directory, it should be noted that chroot() has no effect on the process's cur- rent directory. If the program is already running with an altered root directory, the process's current directory is changed to the same new root directory. This prevents the current directory from being further up the directory tree than the altered root directory. This call is restricted to the super-user. RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate an error. ERRORS
Chroot() will fail and the root directory will be unchanged if: [ENOTDIR] A component of the path name is not a directory. [ENAMETOOLONG] A component of a pathname exceeded {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters. [ENOENT] The named directory does not exist. [EACCES] Search permission is denied for any component of the path name. [ELOOP] Too many symbolic links were encountered in translating the pathname. [EFAULT] Path points outside the process's allocated address space. [EIO] An I/O error occurred while reading from or writing to the file system. SEE ALSO
chdir(2) WARNINGS
There are ways for a root process to escape from the chroot jail. HISTORY
The chroot() function call appeared in 4.2BSD. 4.2 Berkeley Distribution June 4, 1993 4.2 Berkeley Distribution
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