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dash 可以取代 bash 作為我的預設 shell 嗎？

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dash 可以取代 bash 作為我的預設 shell 嗎？

據我所知，dash可以使用命令將其製作為外殼

~$ chsh shirish
Password: 
Changing the login shell for shirish
Enter the new value, or press ENTER for the default
    Login Shell [/bin/bash]:

我只需要安裝 dash 並給出登入 shell /bin/dash 的路徑。如果我這樣做，它不會讀取.bashrc，但可能正在讀取.profile。這是我的.bashrc，我可以直接剪下和貼上嗎.bashrc？

這是我的.bashrc。

$ cat .bashrc
# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=3000
HISTFILESIZE=3000
HISTTIMEFORMAT="%F %T"

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern "**" used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
#[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
    debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
    xterm-color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
    # We have color support; assume it's compliant with Ecma-48
    # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
    # a case would tend to support setf rather than setaf.)
    color_prompt=yes
    else
    color_prompt=
    fi
fi

# enable bash completion in interactive shells
if ! shopt -oq posix; then
  if [ -f /usr/share/bash-completion/bash_completion ]; then
    . /usr/share/bash-completion/bash_completion
  elif [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
  fi
fi

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\t \u@\h:\w\$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
    PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
    ;;
*)
    ;;
esac

# enable color support of ls and also add handy aliases
if [ -x /usr/bin/dircolors ]; then
    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
    alias    ls='ls --color=auto'
    alias   cls='clear'
    alias    ll='ls -l'
    alias aptfn='sudo aptitude forget-new'
    alias  aptn="aptitude search '~N'"
    alias    gi='bash /home/shirish/git-info.sh'
    alias  apto='aptitude search ~o'
    alias  grep='grep --color=auto'
    alias  aptc="aptitude search '~c'"
    alias  copy="rsync --progress -ravz"
    alias   vlc="vlc -vv"
    alias   tor="/home/shirish/.local/share/torbrowser/tbb/x86_64/tor-browser_en-US/start-tor-browser"

    #alias dir='dir --color=auto'
    #alias vdir='vdir --color=auto'
    #alias grep='grep --color=auto'
    #alias fgrep='fgrep --color=auto'
    #alias egrep='egrep --color=auto'
fi

# some more ls aliases

#alias la='ls -A'
#alias l='ls -CF'

# Alias definitions.
# You may want to put all your additions into a separate file like
# ~/.bash_aliases, instead of adding them here directly.
# See /usr/share/doc/bash-doc/examples in the bash-doc package.

#if [ -f ~/.bash_aliases ]; then
#    . ~/.bash_aliases
#fi

# from http://askubuntu.com/questions/16428/showing-a-cowsay-fortune-in-every-new-terminal-session

if [ -x /usr/games/cowsay -a -x /usr/games/fortune ]; then
    fortune | cowsay

答案1

Shell 有兩種用途：執行腳本和互動式命令列。

Dash 被設計為一個快速、有效率的腳本 shell。它幾乎沒有互動式使用的好功能。它沒有花哨的提示、命令列編輯功能或命令歷史記錄。

您可以將 dash 作為登入 shell。它將讀取~/.profile，與其他 Bourne 風格的 shell 相同（除非 bash 特定的~/.bash_profile存在，否則 bash 讀取它）。 Dash 也會ENV在互動運行時讀取數據，就像大多數現代 Bourne 風格的 shell 一樣。

對於互動式使用，請使用功能更強大的 shell：fish、zsh 或 bash。.bashrc除了可以在其他 shell 中工作的別名定義之外，您中的大部分程式碼都是特定於 bash 的。

推薦背景閱讀：登入 Shell 和非登入 Shell 之間的差異？

一些較舊的 Bourne 風格的 shell 在以非互動方式啟動時會讀取 ENV，但我認為任何現代版本都不會這樣做。 Ash 在 2001 年停止了這樣做。

答案2

您中的許多命令.bashrc都是bash特定的。諸如此類的事情HISTCONTROL與 無關dash。命令完成也是如此。不過，別名可以使用。

閱讀 的線上說明頁面dash並檢查您在 中所做的每件事的線上說明頁，.bashrc看看它是否適用於dash.

您問的真正問題不是很清楚：您只是想dash安裝為/bin/sh，還是您真的希望 dash 作為您的登入 shell？如果是後者，那chsh就是正確的做法；否則，您只需要安裝dash，安裝程式將詢問您是否希望 dash 成為預設系統 shell（然後選擇「是」）。如果您想更改答案，請運行dpkg-reconfigure dash。

答案3

您可以輕鬆地親自嘗試一下，看看它們是否有效，而無需更改當前的登入 shell。

除了/etc/profile和之外~/.profile，將以互動方式啟動時dash讀取環境變數指向的文件，如下所示：ENV

ENV=~/.bashrc dash

或更好地複製您的~/.bashrcto~/.dashrc並註解掉/刪除您不需要/不起作用的內容。一旦你擁有了你喜歡的一切，你就可以添加一行

ENV=~/.dashrc

到你的~/.profile並更改你的預設外殼。

從man dash：

 ...   If the environment variable ENV is set on entry to an interac‐
 tive shell, or is set in the .profile of a login shell, the shell next
 reads commands from the file named in ENV.  Therefore, a user should
 place commands that are to be executed only at login time in the
 .profile file, and commands that are executed for every interactive
 shell inside the ENV file.  To set the ENV variable to some file, place
 the following line in your .profile of your home directory

       ENV=$HOME/.shinit; export ENV

 substituting for “.shinit” any filename you wish.

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