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From: peter@ficc.uu.net (Peter da Silva)
Newsgroups: comp.unix.questions
Subject: Re: Piping into Shell scripts
Message-ID: <IL22A+1xds13@ficc.uu.net>
Date: 7 Mar 90 16:56:52 GMT
References: <1990Feb28.142050.11607@virtech.uucp> <10650083@hpisod2.HP.COM>
Reply-To: peter@ficc.uu.net (Peter da Silva)
Organization: Xenix Support, FICC
Lines: 13

> > >Is there any way of getting a Shell script (C or Bourne) to recognise
> > >whether it is receiving input from a pipe?

... bunch of non-optimal answers deleted ...

if [ -t 0 ]
then
  echo "Standard Input is a terminal"
else
  echo "Standard input is not a terminal"
fi

Often, test ("[...]") is a builtin, saving you a fork/exec.
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