chroot [OPTION] NEWROOT [COMMAND [ARG]...]
!subtitle:功能
执行命令时指定根路径。
!subtitle:类型
可执行文件（/usr/sbin/chroot），属于 coreutils。
!subtitle:参数
OPTION 选项：
--groups=G_LIST - 以列表（g1,g2,...,gn）的格式补充组
--userspec=USER:GROUP - 指定用户和组
--skip-chdir - 不更改工作目录
--help - 显示帮助
--version - 显示版本
NEWROOT 要作为根路径的路径
COMMAND 要执行的命令；如果不指定此参数，则切换后运行当前 shell 程序
ARG 命令的参数列表
!subtitle:返回值
125 - chroot 自身失败
126 - COMMAND 无法运行
127 - COMMAND 不存在
其它情况返回 COMMAND 的返回值
$ ls /tmp/ # 查看 /tmp 目录
tmp.XG4RL3jbgF tmp.Urtrw97emL tmp.M8ln2SXW4p
$ mkdir -p ./fake_root/tmp # 创建目录
$ touch ./fake_root/tmp/1.txt # 创建文件
$ wget https://busybox.net/downloads/binaries/1.35.0-x86_64-linux-musl/busybox -O ./fake_root/busybox
$ sudo chroot ./fake_root/ ./busybox ls /tmp/ # 指定 ./fake_root/ 为根目录，查看 /tmp 目录
1.txt
因为将根目录设为
./fake_root/之后，没有/bin目录下的各种命令，因此下载了busybox来执行ls命令。
CHROOT(8) User Commands CHROOT(8)
NAME
chroot - run command or interactive shell with special root directory
SYNOPSIS
chroot [OPTION] NEWROOT [COMMAND [ARG]...]
chroot OPTION
DESCRIPTION
Run COMMAND with root directory set to NEWROOT.
--groups=G_LIST
specify supplementary groups as g1,g2,..,gN
--userspec=USER:GROUP
specify user and group (ID or name) to use
--skip-chdir
do not change working directory to '/'
--help display this help and exit
--version
output version information and exit
If no command is given, run '"$SHELL" -i' (default: '/bin/sh -i').
Exit status:
125 if the chroot command itself fails
126 if COMMAND is found but cannot be invoked
127 if COMMAND cannot be found
- the exit status of COMMAND otherwise
AUTHOR
Written by Roland McGrath.
REPORTING BUGS
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2023 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
chroot(2)
Full documentation <https://www.gnu.org/software/coreutils/chroot>
or available locally via: info '(coreutils) chroot invocation'
GNU coreutils 9.4 April 2024 CHROOT(8)