allex.ps1

#!/bin/bash

# Personal bash PS1 by @allex_wang (https://iallex.com/) {{{
# Last Modified: Mon May 08, 2023 14:22
# GistID: a7c062df0aba27c631aa92971ea83850
# GistURL: https://gist.github.com/a7c062df0aba27c631aa92971ea83850
{
  # set a fancy prompt (non-color, unless we know we "want" color)
  case "$TERM" in
    xterm-256color | xterm-color) 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='\[\e[1;32m\][\u@\h \W]\$\[\e[0m\] '
  else
    # 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
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
  fi

  if type -t __git_ps1 >/dev/null 2>&1; then
    PS1='[\u@\h \W$(__git_ps1 " (%s)")]\$ '
  fi

  ## Add by Allex Wang, 2011/05/08
  ## http://bash.cyberciti.biz/guide/Changing_bash_prompt
  __ps1_cwd() {
    # How many characters of the $PWD should be kept
    maxlen=15
    dir=${PWD##*/}
    p=${PWD/#$HOME/\~}
    parts=$(echo "${p}" | tr "/" " ")
    # Indicate that there has been dir truncation
    trunc_symbol="${parts[0]}/..."
    [ "${trunc_symbol:0:1}" = "~" ] || trunc_symbol="/${trunc_symbol}"
    maxlen=$(( ( maxlen < ${#dir} ) ? ${#dir} : maxlen ))
    local offset=$(( ${#p} - maxlen ))
    if [ ${offset} -gt "0" ]; then
      p=${p:$offset:$maxlen}
      p=${trunc_symbol}/${p#*/}
    fi
    printf %s "$p"
  }

  __ps1_in_docker() {
    (awk -F/ '$2 == "docker"' /proc/self/cgroup | read -r non_empty_input)
  }

  __ps1_init() {
    # 27 = 033 = 0x1b = ^[ = \e
    local c_reset="\[\e[0m\]" # unsets color to term's fg color

    # regular colors
    local k="\[\e[0;30m\]" # black
    local r="\[\e[0;31m\]" # red
    local g="\[\e[0;32m\]" # green
    local y="\[\e[0;33m\]" # yellow
    local b="\[\e[0;34m\]" # blue
    local m="\[\e[0;35m\]" # magenta
    local c="\[\e[0;36m\]" # cyan
    local w="\[\e[0;37m\]" # white

    # emphasized (bolded) colors
    local em_k="\[\e[1;30m\]"
    local em_r="\[\e[1;31m\]"
    local em_g="\[\e[1;32m\]"
    local em_y="\[\e[1;33m\]"
    local em_b="\[\e[1;34m\]"
    local em_m="\[\e[1;35m\]"
    local em_c="\[\e[1;36m\]"
    local em_w="\[\e[1;37m\]"

    # background colors
    local b_k="\[\e[40m\]"
    local b_r="\[\e[41m\]"
    local b_g="\[\e[42m\]"
    local b_y="\[\e[43m\]"
    local b_b="\[\e[44m\]"
    local b_m="\[\e[45m\]"
    local b_c="\[\e[46m\]"
    local b_w="\[\e[47m\]"

    local u_c=$c
    if [ $UID -eq "0" ]; then
      u_c=$r # root's color
    fi

    local _user="\u"
    local _pwd="${em_g}\$(__ps1_cwd)" # \W
    local _git_ps1=
    local prompt_delimit='\\$'

    if [ -n "${SSH_CLIENT:-$SSH_TTY}" ] || __ps1_in_docker; then
      hostname=$(hostname)
      # show current connection ip if hostname is 'localhost'
      if [ "${hostname%%.*}" = "localhost" ]; then
        ip=$(echo "${SSH_CONNECTION}" |cut -f3 -d ' ')
        _user="\u@${ip:-\h}"
      else
        _user="\u@\h"
      fi
    fi

    if type -t __git_ps1 >/dev/null 2>&1; then
      _git_ps1="\$(__git_ps1 \" ${em_c}(%s)${c_reset}\" 2>/dev/null)"
    fi

    PS1="${m}${_user}${c_reset} ${_pwd}${_git_ps1} ${u_c}${prompt_delimit}${c_reset} "
  }

  { [ "$color_prompt" = yes ] && __ps1_init; } || unset __ps1_cwd

  unset __ps1_init color_prompt force_color_prompt
}
# END PS1 }}}

# vim: ft=sh:et:ts=2:sw=2:sts=2:ff=unix:fdm=marker: