Custom bash prompt

prompt.sh

C_BLUE="\[\033[0;34m\]"
C_GREEN="\[\033[0;32m\]"
C_RED="\[\033[0;31m\]"
C_RESET="\[\033[0m\]"

__prompt_git_info() {
    if $(git rev-parse --is-inside-git-dir 2>/dev/null); then
        echo ""
        return
    fi

    if ! (git rev-parse --is-inside-work-tree > /dev/null 2>&1); then
        echo ""
        return
    fi

    local branch_name_or_hash
    local final_git_string=""


    branch_name_or_hash=$(git symbolic-ref --short HEAD 2>/dev/null)
    if [[ -z "$branch_name_or_hash" ]]; then 
        branch_name_or_hash=$(git rev-parse --short HEAD 2>/dev/null)
        if [[ -z "$branch_name_or_hash" ]]; then
            echo ""
            return
        fi
    fi

    local dirty=false
    local state=""


    if git status --porcelain 2>/dev/null | \grep -q '^??'; then
        dirty=true
        state="+"
    elif ! git diff --quiet HEAD 2>/dev/null || ! git diff --quiet 2>/dev/null; then
        dirty=true
        state="+"
    fi

    local git_content="(${branch_name_or_hash})${state}"


    if [[ "$dirty" == true ]]; then
        final_git_string="${C_RED}${git_content}${C_RESET}"
    else
        final_git_string="${C_BLUE}${git_content}${C_RESET}"
    fi

    echo "${final_git_string}"
}


__set_custom_prompt() {
    local EXIT="$?"
    local current_pwd_display
    local current_pwd=$PWD
    local home_dir=$HOME
    local err="${C_RED}\$${C_RESET}"
    if [[ "$EXIT" -eq "0" ]]; then
      err="${C_GREEN}\$${C_RESET}"
    fi

    if [[ "$current_pwd" == "$home_dir" ]]; then
        current_pwd_display="~"
    elif [[ "$current_pwd" == "$home_dir"/* ]]; then
        current_pwd_display="~${current_pwd#$home_dir}"
    else
        current_pwd_display="$current_pwd"
    fi

    local git_info
    git_info=$(__prompt_git_info) 

    if [[ ! -z ${git_info} ]]; then
      git_root=$(git rev-parse --show-toplevel 2>/dev/null)
      if [[ "$git_root" == "$PWD" ]]; then
        PS1="${git_info} ./${PWD##*/} ${err} "
      else
        PS1="${git_info} ${git_root##*/}${PWD#$git_root} ${err} "
      fi
      return
    fi
    PS1="${current_pwd_display} ${err} "
}

PROMPT_COMMAND=__set_custom_prompt