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Re: [PATCH 19/19] bash prompt: alternative git prompt without command substitution

From
SZEDER Gábor <szeder@ira.uka.de>
Date
May 9, 2012, 22:08 UTC
Message-ID
<20120509220844.GG6958@goldbirke>
In-Reply-To
<4FAAC7AE.3020002@pileofstuff.org>
Hi,
On Wed, May 09, 2012 at 08:38:22PM +0100, Andrew Sayers wrote:
Show 7 quoted lines
> On 09/05/12 01:44, SZEDER Gábor wrote:
> >    PROMPT_COMMAND=__git_prompt_command
> 
> Rather than overwrite any existing PROMPT_COMMAND, it would be better to
> do something like:
> 
> PROMPT_COMMAND="__git_prompt_command; $PROMPT_COMMAND"
Show 6 quoted lines
> > +#       Alternatively, to make the above Bash prompt a bit faster:
> > +#               PROMPT_COMMAND=__git_prompt_command
> 
> As above, I'd recommend a simple documentation change:
> PROMPT_COMMAND="__git_prompt_command; $PROMPT_COMMAND"
> (to show people how to chain any other prompt commands they have)

That's a good idea. In fact I did manage to overwrite my $PROMPT_COMMAND and was wondering why did the title of my terminal windows disappear so suddenly...

Show 26 quoted lines
> > @@ -365,7 +371,18 @@ __git_ps1 ()
> >  	fi
> >  
> >  	local f="$w$i$s$u"
> > -	printf -- "${1:- (%s)}" "$c${b##refs/heads/}${f:+ $f}$r$p"
> > +	__git_ps1_string="$c${b##refs/heads/}${f:+ $f}$r$p"
> > +}
> > +
> > +# __git_ps1 accepts 0 or 1 arguments (i.e., format string)
> > +# returns text to add to bash PS1 prompt (includes branch name)
> > +__git_ps1 ()
> > +{
> > +	local __git_ps1_string
> > +	__git_prompt_command
> > +	if [ -n "$__git_ps1_string" ]; then
> > +		printf -- "${1:- (%s)}" "$__git_ps1_string"
> > +	fi
> 
> How hard/appropriate would it be to export individual parts of the
> prompt here?  Something like:
> 
> __git_ps1_string_dirtystate="$i"
> __git_ps1_string_untrackedfiles="$u"
> 
> There have been requests in the past to let people individually
> colourise different bits of the prompt, which this would make practical.

We can't do that from __git_ps1(), because, as I mentioned in the commit message, it must be invoked in a command substitution from $PS1, and what's exported in a subshell that stays in that subshell.

Doing so from __git_prompt_command() would be quite simple: just rename the appropriate variables and don't declare them as local. It would even be more pleasing to the eyes than the current one-letter variable names.

Gábor
Previous: Andrew Sayers
Message 50 of 50 in “Bash prompt speedup”
  1. 00/19 Bash prompt speedupSZEDER Gábor, May 9, 2012
  2. 01/19 tests: move code to run tests under bash into a helper librarySZEDER Gábor, May 9, 2012
  3. 02/19 tests: add tests for the bash prompt functions in the completion scriptSZEDER Gábor, May 9, 2012
  4. Johannes SixtMay 9, 2012
  5. Junio C HamanoMay 9, 2012
  6. Johannes SixtMay 10, 2012
  7. Junio C HamanoMay 9, 2012
  8. SZEDER GáborMay 9, 2012
  9. 03/19 completion: use __gitdir() in _git_log()SZEDER Gábor, May 9, 2012
  10. Junio C HamanoMay 9, 2012
  11. SZEDER GáborMay 9, 2012
  12. 04/19 completion: respect $GIT_DIRSZEDER Gábor, May 9, 2012
  13. Johannes SixtMay 9, 2012
  14. Junio C HamanoMay 9, 2012
  15. 05/19 bash prompt: don't show the prompt when .git/HEAD is unreadableSZEDER Gábor, May 9, 2012
  16. Junio C HamanoMay 9, 2012
  17. SZEDER GáborMay 9, 2012
  18. 06/19 bash prompt: return early from __git_ps1() when not in a git repositorySZEDER Gábor, May 9, 2012
  19. 07/19 completion: make __gitdir() store repository path in $__git_dirSZEDER Gábor, May 9, 2012
  20. Junio C HamanoMay 9, 2012
  21. 08/19 completion: use $__git_dir instead of $(__gitdir)SZEDER Gábor, May 9, 2012
  22. Junio C HamanoMay 9, 2012
  23. SZEDER GáborMay 9, 2012
  24. Junio C HamanoMay 9, 2012
  25. SZEDER GáborMay 9, 2012
  26. 09/19 completion: platform-specific helper function to get physical pathSZEDER Gábor, May 9, 2012
  27. Johannes SixtMay 9, 2012
  28. 10/19 completion: use bash builtins to search for repositorySZEDER Gábor, May 9, 2012
  29. Junio C HamanoMay 9, 2012
  30. SZEDER GáborMay 9, 2012
  31. Junio C HamanoMay 9, 2012
  32. 11/19 bash prompt: use bash builtins to find out current branchSZEDER Gábor, May 9, 2012
  33. Junio C HamanoMay 9, 2012
  34. SZEDER GáborMay 9, 2012
  35. Junio C HamanoMay 9, 2012
  36. SZEDER GáborMay 9, 2012
  37. Junio C HamanoMay 9, 2012
  38. 12/19 bash prompt: use bash builtins to check whether inside git dirSZEDER Gábor, May 9, 2012
  39. Johannes SixtMay 9, 2012
  40. Junio C HamanoMay 9, 2012
  41. 13/19 bash prompt: check whether inside the worktree only when necessarySZEDER Gábor, May 9, 2012
  42. 14/19 bash prompt: use bash builtins to find out current branch during rebaseSZEDER Gábor, May 9, 2012
  43. 15/19 bash prompt: use bash builtins to get detached HEAD abbrev. object nameSZEDER Gábor, May 9, 2012
  44. 16/19 bash prompt: display stash and upstream state even inside the repositorySZEDER Gábor, May 9, 2012
  45. 17/19 bash prompt: use bash builtins to check stash stateSZEDER Gábor, May 9, 2012
  46. 18/19 bash prompt: avoid command substitution when checking for untracked filesSZEDER Gábor, May 9, 2012
  47. Junio C HamanoMay 9, 2012
  48. 19/19 bash prompt: alternative git prompt without command substitutionSZEDER Gábor, May 9, 2012
  49. Andrew SayersMay 9, 2012
  50. SZEDER GáborMay 9, 2012

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