Re: [PATCH] Introduce git version --list-features for porcelain use

Junio C Hamano [off-list ref] wrote:

"Shawn O. Pearce" [off-list ref] writes:

quoted

Why cat?  Tcl is so horribly broken that to get data for both stdout
and stderr through a pipe I have to do something sick like:

	git fetch 2>&1 | cat

because in Tcl its actually:

	set rdr [open "| git fetch |& cat" r]

The |& means 2>&1| in normal shell.  But that means I have to have
a process after it to receive the data.  Normally that's cat.
But MinGW doesn't have cat.  (Nor do they have dog, but neither
does Linux...).  So I need a way to redirect output.

Wait a minute.  Who interprets |& in the above?  Isn't it a
shell?

My understanding was it is Tcl itself.  My $SHELL doesn't understand
it:

  $ echo hi |& cat
  -bash: syntax error near unexpected token `&'

That's why I asked if you are writing for shell-less
environment.  If you are _not_, can't you do something like this
instead?

Ideally with MinGW we wouldn't need a UNIX shell to get things
working in git-gui.  But we have to have one for git-merge for
example, as git-gui doesn't have a builtin Grand Unified Merge
Driver.  Also for git-fetch, which is one of the prime uses of this
cat redirect thing.  ;-)

	set rdr [open "| sh -c 'git fetch 2>&1'" r]

Yeah, I'm already doing that sh -c trick for a different reason in
another context.  I may have to do just that here too.

-- 
Shawn.