From: David Kastrup <dak@gnu.org>
Date: Wed, 06 Jun 2007 09:40:04 GMT
Subject: Re: [PATCH] git-mergetool: Make default smarter by considering user's desktop environment and editor
Message-ID: <86lkexjua3.fsf@lola.quinscape.zz>
In-Reply-To: <7vabvd5u7t.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano <gitster@pobox.com> writes:

> David Kastrup <dak@gnu.org> writes:
>
>> Junio C Hamano <junkio@cox.net> writes:
>>
>>> Josh Triplett <josh@freedesktop.org> writes:
>>>
>>>> Make git-mergetool prefer meld under GNOME, and kdiff3 under KDE.  When
>>>> considering emerge and vimdiff, check $VISUAL and $EDITOR to see which the
>>>> user might prefer.
>>>>
>>>> Signed-off-by: Josh Triplett <josh@freedesktop.org>
>>>
>>> The basic idea is sound.  However...
>>>
>>>  (1) I wonder if we can get rid of the horribly long if .. elif
>>>      chain by using shell function and then iterate a list of them;
>>>
>>>  (2) echo "${VISUAL-$EDITOR}" | grep '^emacs'???
>>>
>>>      Some people may have explicit path (/home/me/bin/emacs),
>>>      and/or runs a variant of emacs called 'xemacs'.  Same for
>>>      vim.
>>
>> Actually, a lot of people run as editor a program called "emacsclient"
>> or "gnuclient": this one connects to an existing Emacs session and
>> passes its arguments to it.  And of course, this is what git-mergetool
>> should then also do.
>
> I do that too, but that is covered by the prefix rule Josh has,
> so it is Ok.

Another note: in my usual Emacs session, EDITOR is set to
/usr/local/emacs-22/bin/emacsclient
which would not be covered...  So that should probably be

useemacs=0
for i in ${VISUAL-$EDITOR}
do
        case "`basename $i`" in [xX][eE]macs*|[eE]macs*|gnuclient*)
             useemacs=1
        esac
        break
done

This should work even when we are talking about something like
EDITOR="C:\My Programs\XEmacs\gnuclient.exe" -n "C:\My Programs\XEmacs\XEmacs"

And it does not require starting grep for something which the shell
can perfectly well handle on its own.  Yes, it does need basename.  I
don't see a good way to avoid that.

-- 
David Kastrup