Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!uw-beaver!tikal!dave
From: dave@tikal.Teltone.COM (news)
Newsgroups: comp.unix.questions
Subject: Re: correct isatty usage
Message-ID: <1161@tikal.Teltone.COM>
Date: 23 Feb 89 16:03:24 GMT
References: <18432@adm.BRL.MIL>
Reply-To: dave@tikal.UUCP (David Karr)
Organization: Teltone Corp., Kirkland, WA
Lines: 30

In article <18432@adm.BRL.MIL> Pabbisetty.henr@xerox.com (Nagesh Pabbisetty) writes:
>> I am trying to use this invokation:
>>
>>         if (isatty (stdin))
>
>
>Use the following segment of code:
>
>	if (isatty(fileno(stdin))) {
>  	        printf("Hello> ");
>   	       fflush(stdout);
>   	       }

Now my question is, how would you do this in a script?  Either C or Bourne.
In C shell, I have this code, but it doesn't appear to work.

if ({`test -t 0`}) then
    echo -n "==> "
else
    echo -n "--> "
endif

It should print "-->" if stdin isn't coming from a terminal, but it doesn't
seem to work that way.  It always prints "==>".

-- 
----------------------------------------
David Karr    dave@tikal.Teltone.COM  or  ...uw-beaver!tikal!dave
Teltone Corp., 10801 120th Ave. NE, Kirkland, WA 98033 (206)827-9626
"The above statements do not necessarily reflect the opinions of my employer."