From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <f2a5c42bf76c887240e8ec236169825b@quanstro.net>
From: erik quanstrom <quanstro@quanstro.net>
Date: Sun, 10 Feb 2008 12:47:56 -0500
To: 9fans@cse.psu.edu
Subject: Re: [9fans] How to move to rc from sh/bash
In-Reply-To: <41F23396-1019-4C8E-A65A-E42824B0E23B@mac.com>
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> It produces the string ' bla$e''o' in rc syntax. The one thing I like
> about two quoting styles  in the Bourne shell is that I can use

it's not so much the number of quotes (there are three, by the way),
it's the complex rules.  for example:

	; /bin/bash
	$ x=1
	$ echo "$x"
	1
	$ echo '$x'
	$x
	$ echo `echo "\$x"`
	1				<- reparsing rule.
	$ echo "'$x'"
	'1'
	$ echo "'\$x'"
	'$x'
but
	$ echo `echo
> The proper is
>
> if [ $bla -eq $otherbla ]; then
> 	:
> fi
>
> The advantage of rc is that that : is not necessary!
>
> Oh, and let's not forget what happens when bla or otherbla is nil! In
> rc,
> 	if (~ $bla $otherbla) { }
> is all that is needed - no hooks.

that's actually a problem.  while ~ is nice, it only does shell matching.
what if you want regexp matching or test (aka on unix [) operators?
then you have exactly the same problem with missing variables.

> And what I dislike:
> - >[2=] is not the same as >[2]/dev/null (some programs crash with
> the former

this isn't a shell issue.  >[2=] closes fd 2.  it's not clear to me that
arbitrary plan 9 programs are expected to run without one of the
three fds they've been promised by convention.

- erik