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From: robertd@ncoast.UUCP (Rob DeMarco)
Newsgroups: comp.unix.questions
Subject: Re: Shell escapes within piped programs
Message-ID: <4241@ncoast.UUCP>
Date: Sun, 23-Aug-87 14:21:49 EDT
Article-I.D.: ncoast.4241
Posted: Sun Aug 23 14:21:49 1987
Date-Received: Wed, 26-Aug-87 06:42:28 EDT
References: <510@cgcha.UUCP>
Reply-To: robertd@ncoast.UUCP (Rob DeMarco)
Organization: Cleveland Public Access UN*X, Cleveland, Oh
Lines: 52
Keywords: shell pipe

In article <510@cgcha.UUCP> wtho@cgcha.UUCP (Tom Hofmann) writes:
>I've just had a strange experience with shell escapes within
>piped programs.  E.g. I called
>
>	   ls | more
>
>and typed
>
>	   !mail <address>
>
>at the "more" prompt.  But instead of being prompted for "Subject:"
>and entering text (as I expected), the rest of the listing to be
>displayed was mailed to <address>, and the "more" prompt returned.
>The reason, as I think, is that standard input of "more" is not
>the terminal but the pipe, and therefore the standard input of the
>invoked program is that pipe as well.  Therefore "mail" reads from
>the pipe and not from the terminal.  I tried it both on a SUN and
>a CADMUS and got the same (strange) result.  I made another test
>using "pg" (System V) instead of "more", and this time I got the
>expected behavior on both machines.
>
>My question:  Shouldn't shell escapes redirect the input (and output)
>to the terminal?
>
>Tom Hofmann
>CIBA-GEIGY AG
>Scientific Computer Center
>P.O. Box				Tel.  +41 61 372059
>CH-4002 Basel
>Switzerland				uucp: ...!mcvax!cgcha!wtho

    I tryed this under Unix System III using "mailx" and got:

    No message !?!

    I tried it again from normal shell and hitting CTRL-D with no message body
and got the same thing.

    Apparently:

    ls -a | more
    !mailx robertd

    Doesn't send ANYTHING to the message body.

		[> Rd
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