Re: [PATCH] make __git_ps1 accept a third parameter in pcmode

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 26, 2012, 20:32 UTC
Message-ID: <7vfw2so8q3.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20121226201944.GA15039@xs4all.nl>

Simon Oosthoek <s.oosthoek@xs4all.nl> writes:

> The problem with doing it in pre-post is when inside non-git
> directories. You want to avoid any gitstring output, including the
> brackets, when not inside a repository.

Ah, Ok, that is probably what I missed.

Show 12 quoted lines

>> Or we could go the other way and drop "pre/post" strings, making
>> them part of the printf_format string.  Perhaps that might be a
>> better interface in the longer term.  Then people can use the same
>> "<pre>%s<post>" format string and do either of these:
>> 
>> 	PS1=$(__git_ps1 "<pre>%s<post>")
>> 	PROMPT_COMMAND='PS1=$(__git_ps1 "<pre>%s<post>")'
>> 
>> without __git_ps1 having a special "prompt command" mode, no?
>
> But how to determine which mode to use?
> In pcmode, you must set the PS1, in command-subsitute mode, you must print a formatted gitstring.

The point of the above two was that __git_ps1 does not have to set PS1 as long as the insn says user to use PROMPT_COMMAND that sets PS1 himself, exactly as illustrated above. In other words, replace the last PS1=... in the "prompt command" mode with an echo or something and make the user responsible for assigning it to PS1 in his PROMPT_COMMAND.

Or put it in another way, I was hoping that we can do without adding the prompt command mode---if there is no two modes, there is no need to switch between them.

But as I said, there probably is a reason why that approach does not work, that is why I said...

>> I have a feeling that I am missing something major, though...