终端第一行没有换行符

Question

我已经修改了我的 Ubuntu 17.10 系统，使其看起来像 macOS。现在我对我的终端的行为感到困惑。换行符显示不正确。这个视频展示了我的意思。

修改后的文件是~/.bashrc. 这些是该文件的新内容：

# ~/.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=1000
HISTFILESIZE=2000

# 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|*-256color) 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

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)}\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 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

# colored GCC warnings and errors
#export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'

# some more ls aliases
alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

# Add an "alert" alias for long running commands.  Use like so:
#   sleep 10; alert
alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '\''s/^\s*[0-9]\+\s*//;s/[;&|]\s*alert$//'\'')"'

# 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

# enable programmable completion features (you don't need to enable
# this, if it's already enabled in /etc/bash.bashrc and /etc/profile
# sources /etc/bash.bashrc).
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

### Prompt style
export PS1="\033[0;33m\h:\W \u\$ \e[m"

我希望有人能理解并帮助解决我的问题。

Answer 1

您似乎已将此添加到.bashrc主目录中文件的末尾：

export PS1="\033[0;33m\h:\W \u\$ \e[m"

你应该改用这个：

export PS1="\[\033[0;33m\]\h:\W \u\$ \[\e[m\]"

即，环绕转义序列，告诉终端如何显示文本（在此情况下，执行彩色化）与\[和\]。这告诉 Bash shell，当您输入的可见字符数确定后，它们不应该被计算在内。（另见这个问题和那个问题。）

顺便说一下，实际export 很少有用PS1。每个新运行的应该使用您的提示的交互式 Bash shell都会读取.bashrc并为自己设置提示。因此，我建议省略export并只使用这一行：

PS1="\[\033[0;33m\]\h:\W \u\$ \[\e[m\]"

虽然这是.bashrc我发现问题的唯一部分，但您可能希望将文件与“原始”文件进行比较：

diff /etc/skel/.bashrc ~/.bashrc

与为.bashrc系统上的新用户创建的文件相比，这显示了更改。通常这只会显示您自己的更改，但有时/etc/skel/.bashrc会在 Ubuntu 版本之间发生更改，因此如果您的用户帐户是在升级之前创建的，则可能会有其他更改。请注意，并非所有显示的内容都是错误！但这些是我建议您检查的部分。

（diff如果您不确定如何解释该命令，或者特定更改的行包含任何应该以不同方式编写的内容，则可以在问题中包含该命令的输出。）

最后，虽然我怀疑这会完全解决您的问题，但我应该提到，通常您按下时的行为Enter实际上不受此影响。更常见的是，省略\[并\]只会导致外壳无法换行，因此如果您键入的内容比终端的宽度长，它会返回到同一行的开头。