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I've modified my Ubuntu 17.10 system to make it look like macOS. Now I'm confused about how my terminal behaves. Line breaks do not appear correctly. This video shows what I mean.

The modified file is ~/.bashrc. These are the new contents of that file:

# ~/.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"

I hope someone can understand and help with my problem.

Zanna
  • 72,312
Aryamaulana Wibisono
  • 37

1 Answers1

6

It appears that you have added this to the end of the .bashrc file in your home directory:

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

You should use this instead:

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

That is, surround escape sequences that tell the terminal how to display text (in this case, that perform colorization) with \[ and \]. This tells the Bash shell that they are not supposed to be counted when the number of visible characters you have entered is determined. (See also this question and that one.)

It's rarely useful to actually export PS1, by the way. Every newly run interactive Bash shell that should use your prompt will read from .bashrc and set the prompt for itself. Therefore I recommend omitting export and just using this line:

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

Although that was the only part of your .bashrc where I noticed a problem, you may want to compare the file with the "original":

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

That shows changes compared to the .bashrc file that would be created for a new user on your system. Usually that has the effect of showing just your own changes, but sometimes /etc/skel/.bashrc changes between Ubuntu releases, so if your user account was created prior to an upgrade, then there may be other changes. Note that not everything this shows is an error! But those are the parts that I recommend you inspect.

(You can include the output of that diff command in your question if you are not sure how to interpret it or if a particular changed line contains anything that ought to be written differently.)

Finally, although I suspect this will completely solve your problem, I should mention that usually the behavior when you press Enter is not actually affected by this. More commonly, omitting \[ and \] just causes the shell to fail to wrap your lines, so that if you type something longer than the width of the terminal, it goes back to the beginning of the same line.

Eliah Kagan
  • 119,640