Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!novavax!twwells!bill
From: bill@twwells.uucp (T. William Wells)
Newsgroups: comp.unix.wizards
Subject: Re: Shell scripts - getting parent status in read
Message-ID: <869@twwells.uucp>
Date: 26 Apr 89 03:38:53 GMT
References: <861@marvin.Solbourne.COM> <849@twwells.uucp> <866@marvin.Solbourne.COM>
Reply-To: bill@twwells.UUCP (T. William Wells)
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In article <866@marvin.Solbourne.COM> dce@Solbourne.com (David Elliott) writes:
: In article <849@twwells.uucp> bill@twwells.UUCP (T. William Wells) writes:
: >[something stupid].
:
: Are you sure about this?

No. I have no idea what drugs I had been slipped when I wrote that. Or
maybe it's lack of sleep? :-)

:        I would think this would cause an EOF, and there was some
: discussion on this recently, but it doesn't.

So would I. And, in fact it does. The problem is that the shell
doesn't exit on EOF. I just tested this on my V/386 3.0 Bourne shell.

I wrote a little shell:

	while true
	do
		read foo
		echo "<$foo>"
	done

to see what happens. And what happens is that EOF and newline both
set foo to a null string.

HEY! I just RTFM. According to it, you get a return status from read!
Adding:

		echo $?

before the other echo, I get 0 on a blank line, 1 on EOF.

When I feed data through a pipe, it works as expected.

(I feel better now I can wipe the egg off my face.)

---
Bill                            { uunet | novavax } !twwells!bill