pimped out zsh prompt

bartman
2010-02-25

Here is [yet another]{zsh-git-prompt} update to the series. I’ve updated my git prompt again, now using the zsh 4.3.7 built in vcs_info module. This time the motivation came from Zsh Prompt Magic article. Here is what it looks like now:

zsh git prompt

Everything is now self contained in one file: S60_prompt. Grab it and source it into your zsh config.

The features are:

name of current branch,
git repo state (rebase, am, bisect, merge, etc),
markers indicating staged/unstaged changes,
- little 1 after branch name indicates dirty working tree,
- little 2 after branch name indicates staged changes,
highlight depth decended into the repository on the right,
show failure of commands via prompt background change,
show command/insert mode when using vi mode (set -o vi).

The big difference in between my usage of the vcs_info and the one from the article, referenced above, is that I have large repositories where updating the status can sometimes take a couple seconds. I like to limit updates as much as possible. In the above config I use the following trick to limit the updates…

I have a PR_GIT_UPDATE variable which dictates weather zsh is going to do the git prompt update before printing the next prompt. It defaults to 1 so I get an update on the first prompt display.

    PR_GIT_UPDATE=1

Next, I’ve setup a function to do the updates when PR_GIT_UPDATE is set.

    function zsh_git_prompt_precmd {
           if [[ -n "$PR_GIT_UPDATE" ]] ; then
                   vcs_info 'prompt'
                   PR_GIT_UPDATE=
           fi
    }

Zsh support precmd which is called before generating the prompt, and you just have to queue up you function in this array:

    precmd_functions+='zsh_git_prompt_precmd'

Next, I have to set the PR_GIT_UPDATE when I change directories:

    function zsh_git_prompt_chpwd {
            PR_GIT_UPDATE=1
    }
    chpwd_functions+='zsh_git_prompt_chpwd'

Lastly, I want to update the prompt after executing certain types of commands:

    function zsh_git_prompt_preexec {
            case "$(history $HISTCMD)" in 
                *git*)
                    PR_GIT_UPDATE=1
                    ;;
            esac
    }
    preexec_functions+='zsh_git_prompt_preexec'

… this is a bit naive, because I could have scripts that execute git commands also, or say if I start up vim and issue :Git commands from within. In those cases I’d have to manually update the prompt with “cd .”. I’d rather have slightly out of date information that have to wait for each prompt to be displayed.

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