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From: gwyn@BRL.ARPA (VLD/VMB)
Newsgroups: net.unix-wizards
Subject: Re: bourne shell \"read\" vs. hangup trap (1)
Message-ID: <70@brl-tgr.ARPA>
Date: Tue, 26-Nov-85 11:16:49 EST
Article-I.D.: brl-tgr.70
Posted: Tue Nov 26 11:16:49 1985
Date-Received: Thu, 28-Nov-85 04:36:00 EST
Sender: news@brl-tgr.ARPA
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Your test script works fine on a real SVR2 Bourne shell.
I suspect your problem is due to the auto-restart of
slow system calls (such as read from a terminal) after
interruption by a signal, a "feature" of 4.2BSD.  There
is some attempt in their /bin/sh to handle the new
signal behavior, but it isn't complete.

Use a BRL Bourne shell instead (or get one from Robbins).