Path: utzoo!utgpu!attcan!uunet!helios!scs!cognos!bradc
From: bradc@cognos.uucp (Brad Cameron)
Newsgroups: comp.sys.ibm.pc
Subject: Re: How to determine stdin/out redirection
Message-ID: <4149@cognos.UUCP>
Date: 29 Sep 88 17:56:24 GMT
References: <9465@cup.portal.com>
Reply-To: bradc@cognos.UUCP (Brad Cameron)
Organization: Cognos Inc., Ottawa, Canada
Lines: 18

In article <9465@cup.portal.com> Steve_R_Calwas@cup.portal.com writes:
>Is there a way for an application program to determine whether or not its
>standard input and/or standard output are being redirected?
>

Microsoft C has a library function called isatty which can be used for
this purpose.  The following function will return non-zero if neither
standard input or standard output are redirected:

int  Interactive ()
{
	 return isatty ( fileno (stdin) ) && isatty ( fileno (stdout) );
}

-- 
Brad Cameron          uucp: decvax!utzoo!dciem!nrcaer!cognos!bradc
Cognos Incorporated   mail: P.O. Box 9707, 3755 Riverside Drive, 
 (613) 738-1440             Ottawa Ontario, Canada. K1G 3Z4