PS1_improved
Posted by Anonymous on Mon 26th Oct 2015 10:36
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#!/bin/bash
# This file is mainly used for bash shell prompt (PS1) configuration.
# Reference material for further reading - http://www.gnu.org/software/bash/manual/bashref.html#Controlling-the-Prompt
# Thanks to all the knowledgeable people in #bash @ irc.freenode.net

# Depends: https://github.com/lhunath/scripts/blob/master/bashlib/bashlib

# Non-UTF8 prompt. Use this when term does not support UTF8.
#PS1="\n\A \[$green\]\[$bold\]\u\[$reset\]@\[$blue\]\H\[$reset\]:\l: \[$bold\]\[$cyan\]\w\[$reset\] [\$?]\[$bold\]\$(__git_ps1)\[$reset\] \n\$ "

# PROMPT_COMMAND runs before the prompt starts.
# Here I specify the colors of the exit status indicator, based on the exit status. More info - http://mywiki.wooledge.org/BashGuide/TestsAndConditionals#Exit_Status
# 0 gets green, 1 gets red and everything else gets a mellow yellow.
PROMPT_COMMAND='case $? in
0) exit_color=$green ;;
1) exit_color=$red ;;
*) exit_color=$yellow ;;
esac'

# Here I specify an array of colors used to give a non-0 job indicator a color.
# So that means that when there are some jobs in the background, the job indicator will get colored.
job_colors=( [0]="$bold$yellow" )

# PS1 depending if the user has root privileges or not.
# Do `sudo bash` and then see the prompt change. (This however might not work on many Red Hat based systems, primarily because of SELinux isolation)
if (( UID > 0 ));

then PS1='\nâ”Œâ”€â”€â”€| ' # Start the prompt with a newline (\n)
         PS1+='\[$bold$cyan\]\w\[$reset\] ]' # This puts the current working directory in bold cyan color, and resets the color to limit the coloring only to the current working dir definition.
         PS1+='(\[$bold$green\]\u\[$reset\]@\[$blue\]\H\[$reset\])' # Here we do exactly the same but with different color and with username and hostname. We also put then inside parentheses for cosmetics.
         PS1+='[$SHELL]' # This is simply the $SHELL variable that you can echo during interactive shell sessions. The square brackets are pure for cosmetics too. Yes, we can put such variables in the PS1 :)
         PS1+='|[\[$white\]\A\[$reset\]][bn:\l]' # The time indicator (according to HH:MM formatting) in white color. Following that we have an indicator for the basename of the shellâ€™s terminal device name.
         PS1+='\[${job_colors[\j==0]}\][j:\j]\[$reset\]' # Let's break this down a bit.
                # You have the ${job_colors[\j==0]} array operation encased inside the non-printing character sequence indicators ( the \[ \] thingies, more info here - http://mywiki.wooledge.org/BashFAQ/053 )
                # You can do arithmetic tests within bash arrays. In our case, this means that when the amount of background jobs equals 0 (\j==0), the outcome of the test will be equal to 'true'.
                # When outcome of the test is equal to true, it will choose the first item in the array (in this case the $bold$yellow we have specified in the job_colors array.
                # To not color any further than we need, we reset the color by issuing \[$reset\].
         PS1+='â–º [\[$exit_color\]$?\[$reset\]]' # Exit status color colored by the $exit_color variable having been set in PROMPT_COMMAND above.
         PS1+='\[$bold\]$(__git_ps1)\[$reset\] ' # Special git indicator, works only if you have git installed.
         PS1+='\nâ””â”€\$ ' # End it with a newline again, so that you don't have the cursor next to the prompt but under it. Also it has the \$ prompt indicator at the end, which changes the prompt to $ when you're a normal user and # when you're the root user.

         # If the user is a root user (so has the UID 0), the following PS1 gets executed:
                else PS1='\nâ”Œâ”€â”€â”€| ' # Start the prompt with a newline (\n)
                         PS1+='\[$bold$red\]\w\[$reset\] ]' # This puts the current working directory in bold RED color, and resets the color to limit the coloring only to the current working dir definition.
                         PS1+='(\[$bold$red\]\u\[$reset\]@\[$blue\]\H\[$reset\])' # Here we do exactly the same but with different color and with username and hostname. We also put then inside parentheses for cosmetics.
                         PS1+='[$SHELL]' # This is simply the $SHELL variable that you can echo during interactive shell sessions. The square brackets are pure for cosmetics too. Yes, we can put such variables in the PS1 :)
                         PS1+='|[\[$white\]\A\[$reset\]][bn:\l]' # The time indicator (according to HH:MM formatting) in white color. Following that we have an indicator for the basename of the shellâ€™s terminal device name.
                         PS1+='\[${job_colors[\j==0]}\][j:\j]\[$reset\]' # Let's break this down a bit.
                                # You have the ${job_colors[\j==0]} array operation encased inside the non-printing character sequence indicators ( the \[ \] thingies, more info here - http://mywiki.wooledge.org/BashFAQ/053 )
                                # You can do arithmetic tests within bash arrays. In our case, this means that when the amount of background jobs equals 0 (\j==0), the outcome of the test will be equal to 'true'.
                                # When outcome of the test is equal to true, it will choose the first item in the array (in this case the $bold$yellow we have specified in the job_colors array.
                                # To not color any further than we need, we reset the color by issuing \[$reset\].
                         PS1+='â–º [\[$exit_color\]$?\[$reset\]]' # Exit status color colored by the $exit_color variable having been set in PROMPT_COMMAND above.
                         PS1+='\[$bold\]$(__git_ps1)\[$reset\] ' # Special git indicator, works only if you have git installed.
                         PS1+='\nâ””â”€\$ ' # End it with a newline again, so that you don't have the cursor next to the prompt but under it. Also it has the \$ prompt indicator at the end, which changes the prompt to $ when you're a normal user and # when you're the root user.
fi