git-PS1 bash prompt setting

git-PS1 bash prompt setting

[Sean]

Ted mentioned in the wart thread that having multiple branches per repo
means that the standard bash prompt isn't as much help as it could be.

For what it's worth i'll post a little script i've been using for quite
some time that helps a little.  It's called git-PS1 and is used by
including it in your bash PS1 variable like so:

export PS1='$(git-PS1 "[\u@\h \W]\$ ")'

If you're not in a git repo, the bash prompt you pass on the git-PS1
command line is used instead.  If you are in a git repo, you'll get
the following as a prompt:

[branch!repo/relative/path]$ 

Where "repo" is the basename of the path to the root of your repo.
An example would look like this:

[master!linus-2.6/Documentation/vm]$ 

Cheers,
Sean


#!/bin/bash
BR=$(git symbolic-ref HEAD 2>/dev/null) || { echo "$@" ; exit ; }
BR=${BR#refs/heads/}
REL=$(git rev-parse --show-prefix) 
REL="${REL//%\/}"
LOC="${PWD%/$REL}"
echo "[$BR!${LOC/*\/}${REL:+/$REL}]$ "

Re: git-PS1 bash prompt setting

[Junio C Hamano]

Sean <seanlkml@sympatico.ca> writes:

> Ted mentioned in the wart thread that having multiple branches per repo
> means that the standard bash prompt isn't as much help as it could be.

Yes, I think this is common issue for everybody not just people
who worked with BK or mercurial.  I find myself almost typing
"pwd" to find out what branch I am on (I do not go as far as
typing "git cd" to switch branches, though).

Re: git-PS1 bash prompt setting

[Johannes Schindelin]

Hi,

On Thu, 16 Nov 2006, Sean wrote:

> For what it's worth i'll post a little script i've been using for quite
> some time that helps a little.  It's called git-PS1 and is used by
> including it in your bash PS1 variable like so:
> 
> export PS1='$(git-PS1 "[\u@\h \W]\$ ")'

I actually like that very much! So much that I tried to implement this as 
an option to an existing builtin (I did not want to clutter the list of 
commands any more...).

But there really is no good place to put it: most commands need a git 
repository, and those which do not, are inappropriate to put an option 
"--show-ps1" into. Except maybe repo-config. Thoughts?

Ciao,
Dscho

Re: git-PS1 bash prompt setting

[Sean]

On Sun, 26 Nov 2006 15:27:07 +0100 (CET)
Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:

> But there really is no good place to put it: most commands need a git 
> repository, and those which do not, are inappropriate to put an option 
> "--show-ps1" into. Except maybe repo-config. Thoughts?

What about just making it an option to the git wrapper?

Re: git-PS1 bash prompt setting

[Johannes Schindelin]

Hi,

On Sun, 26 Nov 2006, Sean wrote:

> On Sun, 26 Nov 2006 15:27:07 +0100 (CET)
> Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> 
> > But there really is no good place to put it: most commands need a git 
> > repository, and those which do not, are inappropriate to put an option 
> > "--show-ps1" into. Except maybe repo-config. Thoughts?
> 
> What about just making it an option to the git wrapper?

D'oh. Too easy!

Thanks,
Dscho

Re: git-PS1 bash prompt setting

[Nicolas Vilz]

On Sun, Nov 26, 2006 at 09:42:12AM -0500, Sean wrote:
> On Sun, 26 Nov 2006 15:27:07 +0100 (CET)
> Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> 
> > But there really is no good place to put it: most commands need a git 
> > repository, and those which do not, are inappropriate to put an option 
> > "--show-ps1" into. Except maybe repo-config. Thoughts?
> 
> What about just making it an option to the git wrapper?

I glued that in my system bashrc with the extension, that it shows to me
user.email out of repo-config, which is also very handy. So I am always
reminded to set my user.credentials in .git/config and i always know which 
role i play in the repository i am working at.

Re: git-PS1 bash prompt setting

[Junio C Hamano]

Nicolas Vilz <niv@iaglans.de> writes:

> I glued that in my system bashrc with the extension, that it shows to me
> user.email out of repo-config, which is also very handy. So I am always
> reminded to set my user.credentials in .git/config and i always know which 
> role i play in the repository i am working at.

I think there is something wrong if the user needs to be
_constantly_ reminded who he is.  Care to explain?

There was a talk on the list about making "git-commit" (and
"git-merge" that does not do a fast-forward) refuse to proceed
until user.nameemail are explicitly set in the configuration.  I
think that particular implementation is a bad idea because it
punishes people who have set up their GECOS and hostname sanely,
but at the same time I do understand that people who just
started to use git would be very unhappy to learn that their
names were misspelled in GECOS field only after accumulating a
couple dozen commits.

Re: git-PS1 bash prompt setting

[Nicolas Vilz]

On Mon, Nov 27, 2006 at 12:48:24AM -0800, Junio C Hamano wrote:
> Nicolas Vilz <niv@iaglans.de> writes:
> 
> > I glued that in my system bashrc with the extension, that it shows to me
> > user.email out of repo-config, which is also very handy. So I am always
> > reminded to set my user.credentials in .git/config and i always know which 
> > role i play in the repository i am working at.
> 
> I think there is something wrong if the user needs to be
> _constantly_ reminded who he is.  Care to explain?

Yes, you are right. It sounds a bit strange. I try to setup a pool of 
configuration data for several linux-boxes which are kind of equal in a 
git repository.

Normally I just pull the config-branch from the repository to the
particular box, but sometimes i have to test the config and alter it...
and other people do as well. And therefore i like to be reminded
constantly who I am.

I glued that in the system bashrc, so I have it for services which
run as users and which configuration data has to be edited by the
services user... also here, several people are working on that machine
and make changes.

Sincerly

Re: git-PS1 bash prompt setting

[Shawn Pearce]

Sean <seanlkml@sympatico.ca> wrote:
> On Sun, 26 Nov 2006 15:27:07 +0100 (CET)
> Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> 
> > But there really is no good place to put it: most commands need a git 
> > repository, and those which do not, are inappropriate to put an option 
> > "--show-ps1" into. Except maybe repo-config. Thoughts?
> 
> What about just making it an option to the git wrapper?

I'm using something like this, and will be adding it to
git-completion.bash tonight:

	__git_ps1 ()
	{
		local b="$(git symbolic-ref HEAD 2>/dev/null)"
		if [ -n "$b" ]; then echo "(${b##refs/heads/})"; fi
	}
	PS1='[\u@\h \W$(__git_ps1)]\$ '

it works very well...

-- 

Re: git-PS1 bash prompt setting

[Jakub Narebski]

Shawn Pearce wrote:

> Sean <seanlkml@sympatico.ca> wrote:
>> On Sun, 26 Nov 2006 15:27:07 +0100 (CET)
>> Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
>> 
>>> But there really is no good place to put it: most commands need a git 
>>> repository, and those which do not, are inappropriate to put an option 
>>> "--show-ps1" into. Except maybe repo-config. Thoughts?
>> 
>> What about just making it an option to the git wrapper?
> 
> I'm using something like this, and will be adding it to
> git-completion.bash tonight:
> 
>       __git_ps1 ()
>       {
>               local b="$(git symbolic-ref HEAD 2>/dev/null)"
>               if [ -n "$b" ]; then echo "(${b##refs/heads/})"; fi
>       }
>       PS1='[\u@\h \W$(__git_ps1)]\$ '
> 
> it works very well...

Perhaps, as it was proposed somewhere else in this thread, instead of
\u@\h use $(git repo-config --get user.email)?

And I would add \!: at the beginning of prompt, but that might be
just me.
-- 
Jakub Narebski
Warsaw, Poland
ShadeHawk on #git

Re: git-PS1 bash prompt setting

[Sean]

On Mon, 27 Nov 2006 01:54:00 -0500
Shawn Pearce <spearce@spearce.org> wrote:

> I'm using something like this, and will be adding it to
> git-completion.bash tonight:
> 
> 	__git_ps1 ()
> 	{
> 		local b="$(git symbolic-ref HEAD 2>/dev/null)"
> 		if [ -n "$b" ]; then echo "(${b##refs/heads/})"; fi
> 	}
> 	PS1='[\u@\h \W$(__git_ps1)]\$ '
> 
> it works very well...

Yeah, when I first coded it I even looked at making it a bash loadable
to make it perform better but found the prototype to run acceptably,
so never bothered.   If Git does get a --show-ps1 option, people will
still be able to roll their own version to tweak the output format
as you did above.  Hopefully the standard format will work for most
though.

Re: git-PS1 bash prompt setting

[Shawn Pearce]

Sean <seanlkml@sympatico.ca> wrote:
> On Mon, 27 Nov 2006 01:54:00 -0500
> Shawn Pearce <spearce@spearce.org> wrote:
> 
> > I'm using something like this, and will be adding it to
> > git-completion.bash tonight:
> > 
> > 	__git_ps1 ()
> > 	{
> > 		local b="$(git symbolic-ref HEAD 2>/dev/null)"
> > 		if [ -n "$b" ]; then echo "(${b##refs/heads/})"; fi
> > 	}
> > 	PS1='[\u@\h \W$(__git_ps1)]\$ '
> > 
> > it works very well...
> 
> Yeah, when I first coded it I even looked at making it a bash loadable
> to make it perform better but found the prototype to run acceptably,
> so never bothered.

When I originally coded the first version of __git_ps1 I was using
it on a Cygwin system, where the fork+exec of the external script
can take a little while.  The time to fork+exec two programs (script
and then git) is huge compared to just fork+exec of git by itself,
so I coded it as a function.  On the other hand my Mac OS X system
doesn't even blink at either implementation.

> If Git does get a --show-ps1 option, people will
> still be able to roll their own version to tweak the output format
> as you did above.  Hopefully the standard format will work for most
> though.

I'm not sure that's worth implementing in the core code.
Most shells that will let you invoke a command as part of their
prompt generation will also let you use builtin functions and do
some basic string manipulation (e.g. like I do above with bash).
At which point it is say 5 lines of shell (nicely formatted) to
craft a prompt string vs. 15-20 lines of C to parse the option,
read HEAD, and craft a prompt string.

If someone else contributes a --show-ps1 option that is useable as
a replacement for my __git_ps1 I'll gladly jump on board and change
to using it, but I just don't see a reason to write it myself.

-- 

Re: git-PS1 bash prompt setting

[Sean]

On Mon, 27 Nov 2006 12:02:49 -0500
Shawn Pearce <spearce@spearce.org> wrote:

> When I originally coded the first version of __git_ps1 I was using
> it on a Cygwin system, where the fork+exec of the external script
> can take a little while.  The time to fork+exec two programs (script
> and then git) is huge compared to just fork+exec of git by itself,
> so I coded it as a function.  On the other hand my Mac OS X system
> doesn't even blink at either implementation.

For sure, that's probably the reason that it was suggested to be
included as a built-in, it would reduce the overhead.

> I'm not sure that's worth implementing in the core code.
> Most shells that will let you invoke a command as part of their
> prompt generation will also let you use builtin functions and do
> some basic string manipulation (e.g. like I do above with bash).
> At which point it is say 5 lines of shell (nicely formatted) to
> craft a prompt string vs. 15-20 lines of C to parse the option,
> read HEAD, and craft a prompt string.

Well, as per my previous message, it might be a little more worthwhile
if it did things like parse an additional format string which let
you reference config variables and relative directory etc.
It would give a lot of flexibility as to what someone wanted to
use as their PS1 when inside a git repo.
 
> If someone else contributes a --show-ps1 option that is useable as
> a replacement for my __git_ps1 I'll gladly jump on board and change
> to using it, but I just don't see a reason to write it myself.

Yeah.. __git_ps1 could just call "git --show-ps1" if it ever comes
into existence ;o)

Re: git-PS1 bash prompt setting

[Nicolas Vilz]

On Thu, Nov 16, 2006 at 01:01:11PM -0500, Sean wrote:

> [branch!repo/relative/path]$ 
> 
> Where "repo" is the basename of the path to the root of your repo.
> An example would look like this:
> 
> [master!linus-2.6/Documentation/vm]$ 
> 
> Cheers,
> Sean
> 
> 
> #!/bin/bash
> BR=$(git symbolic-ref HEAD 2>/dev/null) || { echo "$@" ; exit ; }
> BR=${BR#refs/heads/}
> REL=$(git rev-parse --show-prefix) 
> REL="${REL//%\/}"
> LOC="${PWD%/$REL}"
> echo "[$BR!${LOC/*\/}${REL:+/$REL}]$ "

Just a note:

this doesn't work with bash 3.2. I think they altered the way of
trimming variables in this version.

on systems with bash 3.2 installed, i get
[master!linus-2.6/vm/vm]$ 
with the example above.

on systems with bash 3.1, it works properly.

unfortunatelly, i am not so good in bash scripting, so it will take some
time for me to fix it.

Sincerly

Re: git-PS1 bash prompt setting

[Sean]

On Fri, 17 Nov 2006 09:38:02 +0100
Nicolas Vilz <niv@iaglans.de> wrote:

> Just a note:
> 
> this doesn't work with bash 3.2. I think they altered the way of
> trimming variables in this version.
> 
> on systems with bash 3.2 installed, i get
> [master!linus-2.6/vm/vm]$ 
> with the example above.
> 
> on systems with bash 3.1, it works properly.

Sorry bout that, I knew it was a bit fragile.  Was rather
comical reading Junio's recent message about all the things not
to do if you want portable shell code and noticing my 6 line script
did 90% of them ;o)  Strange though, I downloaded Bash 3.2
and gave it a try and didn't see the problem here..

Wanna try this small change, to see if it helps? :

#!/bin/bash
BR=$(git symbolic-ref HEAD 2>/dev/null) || { echo "$@" ; exit ; }
BR=${BR#refs/heads/}
REL=$(git rev-parse --show-prefix)
REL="${REL%\/}"
LOC="${PWD%/$REL}"
echo "[$BR!${LOC/*\/}${REL:+/$REL}]$ "

Re: git-PS1 bash prompt setting

[Junio C Hamano]

Sean <seanlkml@sympatico.ca> writes:

> On Fri, 17 Nov 2006 09:38:02 +0100
> Nicolas Vilz <niv@iaglans.de> wrote:
>
>> Just a note:
>> 
>> this doesn't work with bash 3.2. I think they altered the way of
>> trimming variables in this version.
>> 
>> on systems with bash 3.2 installed, i get
>> [master!linus-2.6/vm/vm]$ 
>> with the example above.
>> 
>> on systems with bash 3.1, it works properly.
>
> Sorry bout that, I knew it was a bit fragile.  Was rather
> comical reading Junio's recent message about all the things not
> to do if you want portable shell code and noticing my 6 line script
> did 90% of them ;o)

Maybe I should have been more explicit when I said "${paremeter##word}
and friends".  Might not have been obvious, but I only meant the
following four: %, %%, # and ##.

${parameter/pattern/string} and ${parameter//pattern/string} are
not even in POSIX.

Re: git-PS1 bash prompt setting

[Nicolas Vilz]

On Fri, Nov 17, 2006 at 04:20:51AM -0500, Sean wrote:
> On Fri, 17 Nov 2006 09:38:02 +0100
> Nicolas Vilz <niv@iaglans.de> wrote:
> 
> > Just a note:
> > 
> > this doesn't work with bash 3.2. I think they altered the way of
> > trimming variables in this version.
> > 
> > on systems with bash 3.2 installed, i get
> > [master!linus-2.6/vm/vm]$ 
> > with the example above.
> > 
> > on systems with bash 3.1, it works properly.
> 
> Sorry bout that, I knew it was a bit fragile.  Was rather
> comical reading Junio's recent message about all the things not
> to do if you want portable shell code and noticing my 6 line script
> did 90% of them ;o)  Strange though, I downloaded Bash 3.2
> and gave it a try and didn't see the problem here..
> 
> Wanna try this small change, to see if it helps? :
> 
> #!/bin/bash
> BR=$(git symbolic-ref HEAD 2>/dev/null) || { echo "$@" ; exit ; }
> BR=${BR#refs/heads/}
> REL=$(git rev-parse --show-prefix)
> REL="${REL%\/}"
> LOC="${PWD%/$REL}"
> echo "[$BR!${LOC/*\/}${REL:+/$REL}]$ "
> 

That one did the job... funny, removing these two // did the job, for
both versions, 
GNU bash, version 3.1.17(1)-release (powerpc-unknown-linux-gnu) and
GNU bash, version 3.2.5(1)-release (x86_64-pc-linux-gnu).

Thx for fixing that script. It really helps me.

Sincerly
Nicolas