chroot - 改變根目錄

內容簡介

#include <unistd.h>

int chroot(const char **path*);

描述

chroot() 改變根目錄中指定的路徑。此目錄將用於與/開頭的路徑名。根目錄繼承當前進程的的所有子目錄。

Only a privileged process (Linux: one with the CAP_SYS_CHROOT capability) may callchroot(2).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.

返回值

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

錯誤

Depending on the file system, other errors can be returned. The more general errors are listed below:

Error Code

描述

EACCES

Search permission is denied on a component of the path prefix. (See also path_resolution(2).)

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.

遵循於

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

注意

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.

另請參閱

• chdir (2)

• path_resolution (2)