Git prompt with conda and conda-auto-env

The Git Team maintains a bash script that sets a message in your prompt displaying the current branch and status. The script can be found here. To install the script, I have modified the instructions from this tutorial to make it work with conda and the conda-auto-env tool.

First, we are going to assume that conda is install in our system and we will add conda-auto-env. This tools automatically activates the conda environment every time we cd into a folder that has a env.yml or environment.yml files. There are many versions but in this post I will use the one from here modified for bash. Download the file conda_auto_env.sh to any location in your home folder, for instance ~/scripts. Then download the script git-prompt.sh to the same location and add the following to the end of your ~/.bashrc file:

GREEN="\[\033[38;5;155m\]"                                                                                                                                                                                                   
DARK_GREEN="\[\033[00;32m\]"                                                                                                                                                                                                 
GRAY="\[\033[38;5;8m\]"                                                                                                                                                                                                      
ORANGE="\[\033[38;5;220m\]"                                                                                                                                                                                                  
BLUE="\[\033[38;5;117m\]"                                                                                                                                                                                                    
WHITE="\[\033[38;5;15m\]"                                                                                                                                                                                                    
YELLOW="\[\033[01;33m\]"                                                                                                                                                                                                     
LIGHT_GRAY="\[\033[0;37m\]"                                                                                                                                                                                                  
CYAN="\[\033[0;36m\]"                                                                                                                                                                                                        
RED="\[\033[0;31m\]"                                                                                                                                                                                                         
VIOLET="\[\033[01;35m\]"                                                                                                                                                                                                     
MAGENTA="\[\033[0;35m\]".                                                                                                                                                                                                    
RESET="\[$(tput sgr0)\]"   

function git_and_conda_prompt {
  local __git_branch_color="$DARK_GREEN"
  local __git_branch=$(__git_ps1 ' [%s]');

  # colour branch name depending on state

  if [[ "${__git_branch}" =~ "*" ]]; then     # if repository is dirty

      __git_branch_color="$RED"
  elif [[ "${__git_branch}" =~ "$" ]]; then   # if there is something stashed

      __git_branch_color="$YELLOW"
  elif [[ "${__git_branch}" =~ "%" ]]; then   # if there are only untracked files

      __git_branch_color="$LIGHT_GRAY"
  elif [[ "${__git_branch}" =~ "+" ]]; then   # if there are staged files

      __git_branch_color="$CYAN"
  fi

  PS1="${CONDA_PROMPT_MODIFIER}${GREEN}\u${RESET}${GRAY}@${RESET}${ORANGE}\h${RESET}${GRAY}:${RESET}${BLUE}\w${RESET}$__git_branch_color$__git_branch${GRAY}\$${RESET}${WHITE}${RESET} "
}

export PROMPT_COMMAND="conda_auto_env;git_and_conda_prompt"

if [ -f ~/scripts/conda_auto_env.sh ]; then
  source ~/scripts/conda_auto_env.sh
fi

# if .git-prompt.sh exists, set options and execute it

if [ -f ~/scripts/git-prompt.sh ]; then
  GIT_PS1_SHOWDIRTYSTATE=true
  GIT_PS1_SHOWSTASHSTATE=true
  GIT_PS1_SHOWUNTRACKEDFILES=true
  GIT_PS1_SHOWUPSTREAM="auto"
  GIT_PS1_HIDE_IF_PWD_IGNORED=true
  GIT_PS1_SHOWCOLORHINTS=true
  source ~/scripts/git-prompt.sh
fi

Let us explain what the previous code does:

1. Define colors to use for prompt, this will make the PS1 variable easier to modify
2. Define a function git_and_conda_prompt. We get the git status from __git_ps1 (provided by git-prompt.sh) and color the name of the repository according to the status:
   • * unstaged files
   • $ stashed files
   • % untracked files
   • + uncommited files
3. Build the PS1 variable, this line can be customized by changing the information and colors:
   • $CONDA_PROMPT_MODIFIER, current conda environment
   • \u: username
   • \h: hostname
   • \w: working directory
4. Add conda_auto_env (provided by conda_auto_env.sh) and git_and_conda_prompt to the $PROMPT_COMMAND variable. This variable will be executed just before displaying the prompt. The order is important, since we want to activate the environment first (if any) and then display the prompt with all the information.

The variable $CONDA_PROMPT_MODIFIER is set by conda activate and contains the name of the current environment between (). conda init already shows this information in the prompt by setting the PS1 variable, however we have to add it manually to since we are overriding PS1 in the function git_and_conda_prompt.