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Date:	Thu, 23 Sep 1993 18:02:26 -0400
To:	Arnold Robbins <arnold@cc.gatech.edu>
From:	haahr@kaleida.com (Paul Haahr)
X-Sender: haahr@talisman.kaleida.com
Subject: Re: forking builtins
Cc:	rc@hawkwind.utcs.toronto.edu

>althouh i'm sure to be flamed for mentioning the name 'ksh', much of that
>shell's performance comes from strenous effort to avoid forking of builtins
>upon redirection.

it's not that hard conceptually, it just takes some effort to make sure
you catch every reference to file descriptors.  Byron and i came up with
a strategy for es that works.  see es's fd.c for details.

but strenuous it is not.

>i am not advocating that byron rework rc or anything like that. except for
>read, it's not a major problem with the other builtiins, i'm just remarking
>upon it.

echo could also use it.