Re: git-prompt.sh vs leading white space in __git_ps1()::printf_format

From: Simon Oosthoek <s.oosthoek@xs4all.nl>
Date: Dec 11, 2012, 22:47 UTC
Message-ID: <50C7B811.7030006@xs4all.nl>
In-Reply-To: <7vlidltpyj.fsf@alter.siamese.dyndns.org>

Hi Junio

This patch for the documentation doesn't seem to be in rc2 of 1.8.1...

tonight I was explaining this feature to a small group of people and I pulled the git tree to get the latest code.

The current tagged 1.8.1-rc2 doesn't yet have your improvement and after trying to explain it, I think it should be improved even more ;-)

I'm sorry to say I don't have the time right now to make a proper patch, but I'll try to expand below...

On 28/11/12 21:47, Junio C Hamano wrote:

Show 22 quoted lines

> Simon Oosthoek <s.oosthoek@xs4all.nl> writes:
> 
>> perhaps the point should read like this:
>> #    3a) In ~/.bashrc set PROMPT_COMMAND
>> #        To customize the prompt, provide start/end arguments
>> #        PROMPT_COMMAND='__git_ps1 "\u@\h:\w" "\\\$ "'
>>
>> Which would not be confusing at all, I think...
> 
> It says "to customize", so a user who just wants the default (which
> does not exist but the comment does not say so) would be left
> without instruction, no?
> 
>     In $HOME/.bashrc, PROMPT_COMMAND can be set to
>     '__git_ps1 <pre> <post>', where <pre> and <post>
>     are strings you would put in $PS1 before and after
>     the status string generated by git-prompt machinery.
>     e.g.
>         PROMPT_COMMAND='__git_ps1 "\u@\h:\w" "\\\$ "'
> 
> or something?
>

The gist should be that: __git_ps1 can function in two modes; The "traditional" way with command substitution. This mode is activated when the function is provided 0 or 1 arguments. The new way, activated by providing exactly 2 arguments to __git_ps1 is intended for use in the PROMPT_COMMAND way of bash to call a function before writing the prompt. This command can then be (and is in fact) used to set/overwrite the PS1 variable.

Only in the PROMPT_COMMAND mode can you get a prompt with colors for the various states of the git tree showing in the prompt.

An example for inclusion in the ~/.bashrc file is: -----snip----- PROMPT_COMMAND='__git_ps1 "\u@\h:\w" "\\\$ "' GIT_PS1_SHOWDIRTYSTATE=true GIT_PS1_SHOWCOLORHINTS=true --------------

It turns out that it can be quite confusing to get your head around this split personality of __git_ps1...

I hope you can somehow get this into the next release with some improvement to the docs!

Cheers

Simon