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每当打开终端时，都会出现带有 [1] 和 [2] 的行

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每当打开终端时，都会出现带有 [1] 和 [2] 的行

我当时正在看此视频教程在 .bashrc 文件上，我按照 Lubuntu 虚拟机上的教程中的确切步骤进行操作。我的问题是，在编辑并保存文件后，每当我打开终端时，都会在顶部看到两行已输入的内容：

[1]-  Done                     HISTCONTROL=ignorebothhttps://www.youtube.com/watch?v=pYL0iKIyik4     
[2]+  Done                    index=25

我觉得很奇怪，第一行中的 URL 正是我观看的视频教程的 URL，尽管我从未在编辑中包含它。有人能向我解释为什么会发生这种情况吗？我该如何删除这两行？（撤消 .bashrc 中的编辑没有帮助。）

# ~/.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=ignorebothhttps://www.youtube.com/watch?v=pYL0iKIyik4&index=25&list=PLS1QulWo1RIb9WVQGJ_vh-RQusbZgO_As

# 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

答案1

显然你不小心将视频网址复制到了.bashrc：

HISTCONTROL=ignorebothhttps://www.youtube.com/watch?v=pYL0iKIyik4&index=25&list=PLS1QulWo1RIb9WVQGJ_vh-RQusbZgO_As

将此行改回

HISTCONTROL=ignoreboth

然后保存文件，问题就消失了。

这里发生了什么？

通过调用a=b将值分配b给变量a。这里您填充了以下三个变量：

HISTCONTROL=ignorebothhttps://www.youtube.com/watch?v=pYL0iKIyik4&
index=25&
list=PLS1QulWo1RIb9WVQGJ_vh-RQusbZgO_As

因为对于bashshell来说&，是一个将命令分离并发送到后台的操作符。但当命令仅在后台运行时，您不知道它何时结束，因此bash会在结束时通知您。由于分配变量的过程很快就会完成，因此当您的终端仿真器最终决定加载时，前两个变量分配已经完成，因此您看到的第一件事就是您意外发送到后台的两个进程已经完成的友好消息：

Done

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