Changing colors for user, host, directory information in terminal command prompt

Question

Is it possible to change the colors in the command prompt for the user@computer, as well as the the current directory and command parts of the prompt display?

I've already seen something like this done by OSX users, but I don't know how to do the same thing in gnome terminal (I can only change foreground and background colors).

It'd be very useful when, for example, trying to compile programs that have errors, since long, unformatted messages make it hard to distinguish which lines are commands and which are output.

Answer 1

You can edit the settings editing the file: ~/.bashrc.

1. Open the file: gedit ~/.bashrc.

2. Look for the line with #force_color_prompt=yes and uncomment (delete the #).

3. Look for the line below if [ "$color_prompt" = yes ]; then that should looks like:

   PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
   

   Pay attention at the part \u@\h it is saying "user@host" and the number before it \[\033[01;32m\] indicates the color. This is what you have to change. For example, lets change the user to purple, the "@" to black and host to green. Edit the line so it looks like:

   PS1='${debian_chroot:+($debian_chroot)}\[\033[01;35m\]\u\[\033[01;30m\]@\[\033[01;32m\]\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
   

Result:

The colors numbers are:

Black       0;30     Dark Gray     1;30
Blue        0;34     Light Blue    1;34
Green       0;32     Light Green   1;32
Cyan        0;36     Light Cyan    1;36
Red         0;31     Light Red     1;31
Purple      0;35     Light Purple  1;35
Brown       0;33     Yellow        1;33
Light Gray  0;37     White         1;37

References: 1, 2.

Answer 2

You can try the BashrcGenerator. This is by far the easiest way to get a prompt like you want. I've noticed that the colors defined here may be different from your own system, but that's a small issue. With the generated code you can change the colors yourself.

Server user:

export PS1="\[\e[01;37m\][\[\e[0m\]\[\e[01;32m\]\u\[\e[0m\]\[\e[00;37m\]@\[\e[0m\]\[\e[01;34m\]\h\[\e[0m\]\[\e[00;37m\] \[\e[0m\]\[\e[00;37m\]\t\[\e[0m\]\[\e[01;37m\] \W]\\$ \[\e[0m\]"

Server root:

export PS1="\[\e[01;37m\][\[\e[0m\]\[\e[01;31m\]\u\[\e[0m\]\[\e[00;37m\]@\[\e[0m\]\[\e[01;34m\]\h\[\e[0m\]\[\e[00;37m\] \[\e[0m\]\[\e[00;37m\]\t\[\e[0m\]\[\e[01;37m\] \W]\\$ \[\e[0m\]"

And if needed you can change hostname color to reflect different type of servers.

I use different format for my local computer:

export PS1="\[\e[01;33m\]\u\[\e[0m\]\[\e[00;37m\]@\[\e[0m\]\[\e[01;36m\]\h\[\e[0m\]\[\e[00;37m\] \t \[\e[0m\]\[\e[01;35m\]\w\[\e[0m\]\[\e[01;37m\] > \[\e[0m\]"

My favorite now:

export PS1="\n\[\e[01;33m\]\u\[\e[0m\]\[\e[00;37m\]@\[\e[0m\]\[\e[01;36m\]\h\[\e[0m\]\[\e[00;37m\] \t \[\e[0m\]\[\e[01;35m\]\w\[\e[0m\]\[\e[01;37m\] \[\e[0m\]\n$ "

This last prompt has one nice touch. It adds a newline after the prompt, and an empty newline before. Now you can display the complete directory path without problem, and it makes it more clear where a new command starts, in case of long output.

Answer 3

For details, see this detailed HOWTO.

In short, you can alter the prompt by editing the $PS1 environment variable. There's so much to say here, that I'll just show you my prompt and refer you to the link above for more details.

The color-related parts are in the function setPrompt:

# This function from: https://wiki.archlinux.org/index.php/Color_Bash_Prompt_%28%D0%A0%D1%83%D1%81%D1%81%D0%BA%D0%B8%D0%B9%29#Wolfman.27s
##################################################
# Fancy PWD display function
##################################################
# The home directory (HOME) is replaced with a ~
# The last pwdmaxlen characters of the PWD are displayed
# Leading partial directory names are striped off
# /home/me/stuff          -> ~/stuff               if USER=me
# /usr/share/big_dir_name -> ../share/big_dir_name if pwdmaxlen=20
##################################################
bash_prompt_shortener() {
    # How many characters of the $PWD should be kept
    local pwdmaxlen=25
    # Indicate that there has been dir truncation
    local trunc_symbol=".."
    local dir=${PWD##*/}
    pwdmaxlen=$(( ( pwdmaxlen < ${#dir} ) ? ${#dir} : pwdmaxlen ))
    NEW_PWD=${PWD/#$HOME/\~}
    local pwdoffset=$(( ${#NEW_PWD} - pwdmaxlen ))
    if [ ${pwdoffset} -gt "0" ]
    then
        NEW_PWD=${NEW_PWD:$pwdoffset:$pwdmaxlen}
        NEW_PWD=${trunc_symbol}/${NEW_PWD#*/}
    fi
}


function setPrompt {
  COLOR1="\[\033[1;33m\]"     #First color
  COLOR2="\[\033[0;33m\]"     #Second color
  NO_COLOR="\[\033[0m\]"      #Transparent - don't change

  case $TERM in 
    xterm*)
      TITLEBAR="\[\033]0;\h - \w\007\]"
      ;;
    *)
      TITLEBAR=""
      ;;
  esac

  local dash_open="${COLOR1}-${COLOR2}-"
  local dash_close="${COLOR2}-${COLOR1}-"
  local spacer="${COLOR2}-"
  local jobs_and_history="${COLOR2}(${COLOR1}\!${COLOR2}:${COLOR1}\j${COLOR2})"
  local user_host="${COLOR2}(${COLOR1}\u${COLOR2}@${COLOR1}\H${COLOR2})"
  local host="${COLOR2}(${COLOR1}\H${COLOR2})"
  local root_or_not="${COLOR2}(${COLOR1}\\\$${COLOR2})"
  local cwd="${COLOR2}(${COLOR1}\w${COLOR2})"
  #PS1="${TITLEBAR}${COLOR1}-${COLOR2}-(${COLOR1}\!${COLOR2}:${COLOR1}\j${COLOR2})-(${COLOR1}\w${COLOR2})-${COLOR1}-\n-${COLOR2}-(${COLOR1}\u${COLOR2}@${COLOR1}\H${COLOR2})-(${COLOR1}\\\$${COLOR2})-${COLOR1}- ${NO_COLOR}"
  #PS1="${TITLEBAR}${dash_open}${cwd}${spacer}${root_or_not}${dash_close}\n${dash_open}${jobs_and_history}${spacer}${host}${dash_close}${NO_COLOR} "
  #PS2="${COLOR2}--${COLOR1}- ${NO_COLOR}"
  PS1="${TITLEBAR}${COLOR1}"'${NEW_PWD}'"${COLOR2}:\$${NO_COLOR} "
  PS2="$spacer$dash_close$NO_COLOR "
}

bash_prompt_shortener
setPrompt
unset setPrompt

#Determine and display the exit Status of the last command, if non-zero.
function checkExitStatus() {
  local status="$?"
  local signal=""
  local COLOR1="\033[0;0;33m"     #First color
  local COLOR2="\033[0;0;36m"     #Second color
  local NO_COLOR="\033[0m"        #Transparent - don't change

  if [ ${status} -ne 0 -a ${status} != 128 ]; then
    # If process exited by a signal, determine name of signal.
    if [ ${status} -gt 128 ]; then
      signal="$(builtin kill -l $((${status} - 128)) 2>/dev/null)"
      if [ "$signal" ]; then
        signal="$signal"
      fi
    fi
    echo -e "${COLOR1}[Exit ${COLOR2}${status} ${signal}${COLOR1}]${NO_COLOR}" 1>&2
    #echo -ne "${COLOR1}[Exit ${COLOR2}${status}${COLOR1} ${COLOR2}${signal}${COLOR1}]${NO_COLOR} " 1>&2
    fi
  return 0
}
print_prompt_time() {
    printf "%*s\r" $(tput cols) "$(date '+%T')"
}

promptCmd() {
    checkExitStatus
    print_prompt_time
}

PROMPT_COMMAND=promptCmd

In addition to colors, my prompt has a few other features, such as abbreviated directory names (see the function bash_prompt_shortener), automatic display of the last command's exit status if nonzero (function checkExitStatus), and display of the time in the rightmost columns (function print_prompt_time).