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Date:	Wed, 1 Jul 1992 17:30:14 -0400
From:	hugh@mimosa.com ("D. Hugh Redelmeier")
Message-Id: <9207012130.AA10806@redvax.mimosa.com>
To:	Gerry.Tomlinson@newcastle.ac.uk, rc@hawkwind.utcs.toronto.edu
Subject: Re: -s flag

| respecting $SHELL so I can use all my rc functions. If instead I execed
| $SHELL -s with the command line as stdin, with the filenames as the
| arguments, and set the environment variable i to be that of the current
| file, then one could reference all files with $*, numbered files with $n,
| and the current file with $i, without xp having to touch the user's
| input. Much nicer I think.

I suspect that you would be better off using -c.  It too allows
passing parameters to the command.  That way you need not fool with
stdin.

As a matter of taste, I have misgivings about taking over $i.  It is
a variable name that I frequently use in scripts.  That is the
beauty of $1 etc.: those names were already reserved for this
mechanism.  Of course, $current is a bit tiresome to type.

Unfortunately, the positional parameters after -c or -s are not
treated the same in different shells (at least under SunOS4.0.3):

	$ sh -c 'echo $*' one two
	two
	$ sh -c 'echo $0 $1' one two
	one two

	$ csh -c 'echo $*' one two
	one two
	$ csh -c 'echo $0 $1' one two
	No file for $0.

	$ rc -c 'echo $*' one two
	one two
	$ rc -c 'echo $0 $1' one two
	rc one
[This is an old version of rc; it may have changed.]

	$ sh -si one two
	$ echo $*
	one two
	$ echo $0 $1
	sh one
	$ exit

	$ csh -si one two
	redvax% echo $*
	one two
	redvax% echo $0 $1
	No file for $0.
	redvax% exit

	$ rc -si one two
	rc: illegal option -- s
	$ rc -i one two
	one: No such file or directory

For portability reasons, I only promise to set $1, and I do so by
passing two copies of the string as positional parameters.

Hugh Redelmeier
hugh@mimosa.com or {utcsri, uunet!attcan, utzoo, scocan}!redvax!hugh
When all else fails: hugh@csri.toronto.edu
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