Display git branch in bash prompt

.bashrc

# If you work with git, you've probably had that nagging sensation of not knowing what branch you are on. Worry no longer!

export PS1="\\w:\$(git branch 2>/dev/null | grep '^*' | colrm 1 2)\$ "

# This will change your prompt to display not only your working directory but also your current git branch, if you have one. Pretty nifty!

# ~/code/web:beta_directory$ git checkout master
# Switched to branch "master"
# ~/code/web:master$ git checkout beta_directory
# Switched to branch "beta_directory"
# ~/code/web:beta_directory$ 

-> by NOT performing any git state computation, when the working directory has NOT changed.

But then the prompt doesn't change when you switch branches.

-> by NOT performing any git state computation, when the working directory has NOT changed.

But then the prompt doesn't change when you switch branches.

You're correct.
So let's improve & rephrase the optimization :
"-> by NOT performing any git state computation, UNLESS the working directory has changed, OR git command was run."

I updated my original proposed solution accordingly.

I created my own version for displaying the git branch in prompt starting from @vankasteelj reply (wrote on Mar 7, 2016).

It is a simple solution that includes branch status color. Take a look:

parse_git_bg() {
  if [[ $(git status -s 2> /dev/null) ]]; then
    echo -e "\033[0;31m"
  else
    echo -e "\033[0;32m"
  fi
}

PS1='\[\033[0;32m\]\[\033[0m\033[0;32m\]\u\[\033[0;34m\]@\[\033[0;34m\]\h \w\[$(parse_git_bg)\]$(__git_ps1)\n\[\033[0;32m\]\$\[\033[0m\] 

Based. Thanks.

1 as True or correct command, and if it is 0, then it is false or wrong.

parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/'
}

export PS1="╭─╼[\[\e[1;36m\]\w\[\e[0m\]]-(\`if [ \$? = 0 ]; then echo \[\e[32m\]1\[\e[0m\]; else echo \[\e[31m\]0\[\e[0m\]; fi\`)-[\[\e[1;32m\]\h\[\e[0m\]]\n╰─ \u\$(if git rev-parse --git-dir > /dev/null 2>&1; then echo '@git:('; fi)\[\e[1;34m\]\$(parse_git_branch)\[\e[0m\]\$(if git rev-parse --git-dir > /dev/null 2>&1; then echo ')'; fi) >> "


PROMPT_DIRTRIM=2

Good job! Thank you a lot!

Thank you