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From: pechner@ddtg.com (Michael Pechner)
Newsgroups: comp.unix.questions
Subject: Re: How do I tell if STDIN is a PIPE?
Message-ID: <1991Jun7.214926.20486@ddtg.com>
Date: 7 Jun 91 21:49:26 GMT
References: <653@eskimo.celestial.com> <23190@shlump.lkg.dec.com> <494@ulticorp.UUCP>
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In article <494@ulticorp.UUCP> rick@ulticorp.UUCP (Rick Poleshuck) writes:
>In article <23190@shlump.lkg.dec.com> lan_csse@netrix.nac.dec.com (CSSE LAN Test Account) writes:
>>In article <653@eskimo.celestial.com> nanook@eskimo.celestial.com (Robert Dinse) writes:
>>>In article <1991May30.101153.27842@thunder.mcrcim.mcgill.edu>, mouse@thunder.mcrcim.mcgill.edu (der Mouse) writes:
>>>> In article <1991May26.172328.713@arizona.edu>, jjr@ace.ece.arizona.edu (Jeffrey J. Rodriguez) writes:
>>>> 
>>>> > How do I tell whether stdin is coming from a pipe?
>>>> 
>
>/* this looks real stupid but is quite portable */
>if ( lseek( 0, 0l, 0 ) < 0 && errno == ESPIPE )
>	puts( "stdin is from a pipe" );
>
>-- 
>		| Email - !uunet!ulticorp!ultixrs!rick
>Rick Poleshuck 	| Voice - (201) 887-9222 Ext. 755
>		| Mail  - The Ultimate Corporation, East Hanover, NJ 07936

This error is not just for pipes. It is for non_seekable 
devices in general.

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pechner@ddtg.com (Michael Pechner)  | Pizza Probably The Worlds Most
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