Active command prompt for git, backgrounded jobs, exit codes, etc. for bash users.

active-prompt-for-bashrc.sh

# command_prompt()
#
# Follow the instructions below to add fonts and git prompt support, then
# add this scriptlet to your .bashrc.
#
# Function that is executed each time a command is run to update the PS1 
# variable (ie: prompt).  To configure, let's put some fonts in place. 
# Download and install Gabriele Lana's Awesome Fonts:
#
# https://github.com/gabrielelana/awesome-terminal-fonts/archive/master.zip
# 
# Unzip the archive and run the install.sh from the resulting 
# awesome-terminal-fonts-master  folder to install some fonts. Some .sh files
# will also be installed in ~/.fonts to provide constants for each font that 
# can be used in scripts.
#
# If using git, install the git-prompt.sh script in your home folder and add
# to .bashrc:
#
# curl -L -o ~/.git-prompt.sh https://raw.githubusercontent.com/git/git/master/contrib/completion/git-prompt.sh
# chmod +x ~/.git-prompt.sh
# echo 'source ~/.git-prompt.sh' >> ~/.bashrc
#
# You'll need to log out and back in to pull that in, or you'll need to source
# the ~/.git-prompt.sh in your current session to test it.
#
# Color scheme is based on a dark background. If using a light background,
# you'll want to experiment with the colors.
command_prompt() {
    #=========================================================
    # Capture EXIT_CODE MUST BE FIRST!!!
    #=========================================================
    local EXIT_CODE="$?"

    # Reset the PS1 (Prompt String)
    PS1=""

    # exit code output variables
    local exit_code=""
    local exit_code_color=""

    # CONSTANTS
    # Colors for bash prompt
    # foreground colors, use with echo -e
    local RESET='\[\e[m\]'       # No Color, reset
    #     normal                 bright                  high intensity          bright + high intensity
    local DKGREY='\[\e[0;30m\]'
    local LTGREY='\[\e[1;30m\]'
    local RED='\[\e[0;31m\]'     BRED='\[\e[1;31m\]'     IRED='\[\e[0;91m\]'     BIRED='\[\e[1;91m\]'
    local GREEN='\[\e[0;32m\]'   BGREEN='\[\e[1;32m\]'   IGREEN='\[\e[0;92m\]'   BIGREEN='\[\e[1;92m\]'
    local YELLOW='\[\e[0;33m\]'  BYELLOW='\[\e[1;33m\]'  IYELLOW='\[\e[0;93m\]'  BIYELLOW='\[\e[1;93m\]'
    local BLUE='\[\e[0;34m\]'    BBLUE='\[\e[1;34m\]'    IBLUE='\[\e[0;94m\]'    BIBLUE='\[\e[1;94m\]'
    local PURPLE='\[\e[0;35m\]'  BPURPLE='\[\e[1;35m\]'  IPURPLE='\[\e[0;95m\]'  BIPURPLE='\[\e[1;95m\]'
    local CYAN='\[\e[0;36m\]'    BCYAN='\[\e[1;36m\]'    ICYAN='\[\e[0;96m\]'    BICYAN='\[\e[1;96m\]'
    local GREY='\[\e[0;37m\]'    BGREY='\[\e[1;37m\]'   
    local WHITE='\[\e[0;97m\]'   BWHITE='\[\e[1;97m\]'

    local sym_radioactive=$(echo -e '\u2622')
    local sym_warning=$(echo -e '\u26A0')
    local sym_check_mark=$(echo -e '\u2714')
    local sym_cancel=$(echo -e '\u2718')
    local sym_sparkle="$(echo -e '\u2728')"
    local sym_arrow="$(echo -e '\u2937')"
    local sym_line="$(echo -e '\u2574')"
    local sym_left_arrow_up="$(echo -e '\u2b11')"
    local sym_background_process="$(echo -e '\u2749')"
    local sym_colon="$(echo -e '\u003A')"

    local user="${CYAN}\u${RESET}"
    local host="${ICYAN}\h${RESET}"
    local workdir="${YELLOW}\W${RESET}"
    local git_branch=""
    local git_symbols=""

    # is user in an SSH session?
    local bracket_color="" # default
    if [[ $SSH_CLIENT ]] || [[ $SSH2_CLIENT ]]; then
        bracket_color="${BPURPLE}"
    fi

    # check if user has ~/.git-prompt.sh loaded and run 
    # __git_ps1 if possible
    local git_ps1=""
    if declare -F __git_ps1 &>/dev/null; then
        git_ps1=$(__git_ps1)
        
        if [ -n "${git_ps1}" ]; then
            # remove unnecessary characters to clean the prompt
            git_ps1="${git_ps1##*( )}"
            git_ps1="${git_ps1//[(]}"
            git_ps1="${git_ps1//[]]}"

            # colour branch name depending on state
            # make the symbols easier to see.
            local git_branch_color="$GREEN"
            # staged files, committed but not pushed
            if [[ "${git_ps1}" =~ "+" ]]; then
                git_branch_color="${CYAN}"
                git_ps1="${git_ps1//[+]}"
                git_symbols+=" +"
            fi
            # if there is something stashed
            if [[ "${git_ps1}" =~ "$" ]]; then
                git_branch_color="${YELLOW}"
                git_ps1="${git_ps1//[$]}"
                git_symbols+=" $"
            fi
            # unstaged/uncommitted files (dirty)
            if [[ "${git_ps1}" =~ "*" ]]; then
                git_branch_color="${YELLOW}"
                git_ps1="${git_ps1//[*]}"
                git_symbols+=" *"
            fi
            # branch is ahead
            if [[ "${git_ps1}" =~ ">" ]]; then
                git_branch_color="${YELLOW}"
                git_ps1="${git_ps1//[>]}"
                git_symbols+=" >"
            fi
            # branch is behind
            if [[ "${git_ps1}" =~ "<" ]]; then
                git_branch_color="${YELLOW}"
                git_ps1="${git_ps1//[<]}"
                git_symbols+=" <"
            fi
            # untracked files
            if [[ "${git_ps1}" =~ "%" ]]; then
                git_branch_color="${RED}"
                git_ps1="${git_ps1//[%]}"
                git_symbols+=" %"
            fi
            git_branch="[[${git_branch_color}${git_ps1}${RESET}${git_symbols}${RESET}]]"
        fi
    fi

    case ${EXIT_CODE} in
        0)   exit_code="${sym_check_mark}"
             exit_code_color="${BGREEN}"
             ;;
        127) exit_code="${sym_warning}" # command not found
             exit_code_color="${BIRED}"
             ;;
        130) exit_code="${sym_cancel}"  # control-c
             exit_code_color="${BYELLOW}"
             ;;
        148) exit_code="${sym_sparkle}" # backgrounded command
             exit_code_color="${BCYAN}"
             ;;
        *)   exit_code="${EXIT_CODE}"   # other error code
             exit_code_color="${RED}"
             ;;
    esac

    # backgrounded and paused jobs in the current session.
    local jobs_details=""
    local bg_jobs=$(jobs -r | wc -l )
    (( bg_jobs > 0 )) && jobs_details="${YELLOW}${sym_background_process}${RESET}${sym_colon}${WHITE}${bg_jobs}${RESET} "
    (( bg_jobs > 3 )) && jobs_details="${RED}${sym_background_process}${RESET}${sym_colon}${WHITE}${bg_jobs}${RESET} "

    local st_jobs=$(jobs -s | wc -l )
    (( st_jobs > 0 )) && (( st_jobs <= 3 )) && jobs_details+="${LTGREY}${sym_background_process}${RESET}${sym_colon}${WHITE}${st_jobs}${RESET}"
    (( st_jobs > 3 )) && jobs_details+="${LTGREY}${sym_background_process}${RESET}${sym_colon}${WHITE}${st_jobs}${RESET}"

    # assemble the prompt
    [ -n "${git_branch}" ] && PS1+="${git_branch}"
    [ -n "${jobs_details}" ] && PS1+="${jobs_details}"
    [ -n "${PS1}" ] && PS1+="\n"

    PS1+="${LTGREY}${sym_arrow} ${RESET}"
    PS1+="${exit_code_color}${exit_code} ${RESET}"
    PS1+="${bracket_color}[${RESET}${user}@${host}${bracket_color}][${RESET}${workdir}${bracket_color}]${RESET}$ "
}

configure_ps1() {
    # configure PROMPT_COMMAND which is executed each time before PS1
    # the history commands will ensure the command history file is
    # updated immediately and reloaded with no duplicates.
    export PROMPT_COMMAND='command_prompt; history -a; history -c; history -r;'
}

# Set the PROMPT_COMMAND and remove the configure function.
configure_ps1
unset -f configure_ps1