Windows 使用 Linux 子系统，轻轻松松安装多个linux

Ubantu的帮助：
hann@HannYang:~$ help
GNU bash, version 5.0.17(1)-release (x86_64-pc-linux-gnu)
These shell commands are defined internally.  Type `help' to see this list.
Type `help name' to find out more about the function `name'.
Use `info bash' to find out more about the shell in general.
Use `man -k' or `info' to find out more about commands not in this list.
Debian的帮助：
hann@HannYang:~$ help
GNU bash, version 5.2.15(1)-release (x86_64-pc-linux-gnu)
These shell commands are defined internally.  Type `help' to see this list.
Type `help name' to find out more about the function `name'.
Use `info bash' to find out more about the shell in general.
Use `man -k' or `info' to find out more about commands not in this list. 
两者列出的内部命令列表基本相同：
 job_spec [&]                                   history [-c] [-d offset] [n] or history -an>
 (( expression ))                               if COMMANDS; then COMMANDS; [ elif COMMANDS>
 . filename [arguments]                         jobs [-lnprs] [jobspec ...] or jobs -x comm>
 :                                              kill [-s sigspec | -n signum | -sigspec] pi>
 [ arg... ]                                     let arg [arg ...]
 [[ expression ]]                               local [option] name[=value] ...
 alias [-p] [name[=value] ... ]                 logout [n]
 bg [job_spec ...]                              mapfile [-d delim] [-n count] [-O origin] [>
 bind [-lpsvPSVX] [-m keymap] [-f filename] [>  popd [-n] [+N | -N]
 break [n]                                      printf [-v var] format [arguments]
 builtin [shell-builtin [arg ...]]              pushd [-n] [+N | -N | dir]
 caller [expr]                                  pwd [-LP]
 case WORD in [PATTERN [| PATTERN]...) COMMAN>  read [-ers] [-a array] [-d delim] [-i text]>
 cd [-L|[-P [-e]] [-@]] [dir]                   readarray [-d delim] [-n count] [-O origin]>
 command [-pVv] command [arg ...]               readonly [-aAf] [name[=value] ...] or reado>
 compgen [-abcdefgjksuv] [-o option] [-A acti>  return [n]
 complete [-abcdefgjksuv] [-pr] [-DEI] [-o op>  select NAME [in WORDS ... ;] do COMMANDS; d>
 compopt [-o|+o option] [-DEI] [name ...]       set [-abefhkmnptuvxBCHP] [-o option-name] [>
 continue [n]                                   shift [n]
 coproc [NAME] command [redirections]           shopt [-pqsu] [-o] [optname ...]
 declare [-aAfFgilnrtux] [-p] [name[=value] .>  source filename [arguments]
 dirs [-clpv] [+N] [-N]                         suspend [-f]
 disown [-h] [-ar] [jobspec ... | pid ...]      test [expr]
 echo [-neE] [arg ...]                          time [-p] pipeline
 enable [-a] [-dnps] [-f filename] [name ...>   times
 eval [arg ...]                                 trap [-lp] [[arg] signal_spec ...]
 exec [-cl] [-a name] [command [arguments ...>  true
 exit [n]                                       type [-afptP] name [name ...]
 export [-fn] [name[=value] ...] or export ->   typeset [-aAfFgilnrtux] [-p] name[=value] .>
 false                                          ulimit [-SHabcdefiklmnpqrstuvxPT] [limit]
 fc [-e ename] [-lnr] [first] [last] or fc -s>  umask [-p] [-S] [mode]
 fg [job_spec]                                  unalias [-a] name [name ...]
 for NAME [in WORDS ... ] ; do COMMANDS; don>   unset [-f] [-v] [-n] [name ...]
 for (( exp1; exp2; exp3 )); do COMMANDS; don>  until COMMANDS; do COMMANDS; done
 function name { COMMANDS ; } or name () { CO>  variables - Names and meanings of some shel>
 getopts optstring name [arg]                   wait [-fn] [id ...]
 hash [-lr] [-p pathname] [-dt] [name ...]      while COMMANDS; do COMMANDS; done
 help [-dms] [pattern ...]                      { COMMANDS ; }