chroot(2)

1CHROOT(2)                  Linux Programmer's Manual                 CHROOT(2)
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NAME

6       chroot - change root directory
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SYNOPSIS

9       #include <unistd.h>
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11       int chroot(const char *path);
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DESCRIPTION

14       chroot()  changes  the  root directory to that specified in path.  This
15       directory will be used for pathnames beginning with /.  The root direc‐
16       tory is inherited by all children of the current process.
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18       Only  a privileged process (Linux: one with the CAP_SYS_CHROOT capabil‐
19       ity) may call chroot(2).
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21       This call changes an ingredient in the pathname resolution process  and
22       does nothing else.
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24       This  call does not change the current working directory, so that after
25       the call `.' can be outside the tree rooted at `/'.  In particular, the
26       superuser  can  escape from a `chroot jail' by doing `mkdir foo; chroot
27       foo; cd ..'.
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29       This call does not close open file descriptors, and such file  descrip‐
30       tors may allow access to files outside the chroot tree.
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RETURN VALUE

33       On  success,  zero is returned.  On error, -1 is returned, and errno is
34       set appropriately.
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ERRORS

37       Depending on the file system, other errors can be returned.   The  more
38       general errors are listed below:
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40       EACCES Search  permission  is denied on a component of the path prefix.
41              (See also path_resolution(2).)
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43       EFAULT path points outside your accessible address space.
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45       EIO    An I/O error occurred.
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47       ELOOP  Too many symbolic links were encountered in resolving path.
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49       ENAMETOOLONG
50              path is too long.
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52       ENOENT The file does not exist.
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54       ENOMEM Insufficient kernel memory was available.
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56       ENOTDIR
57              A component of path is not a directory.
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59       EPERM  The caller has insufficient privilege.
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CONFORMING TO

62       SVr4, 4.4BSD, SUSv2 (marked LEGACY).  This  function  is  not  part  of
63       POSIX.1-2001.
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NOTES

66       A  child  process created via fork(2) inherits its parent's root direc‐
67       tory.  The root directory is left unchanged by execve(2).
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69       FreeBSD has a stronger jail() system call.
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