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From: dkeisen@leland.Stanford.EDU (Dave Eisen)
Newsgroups: comp.unix.questions,comp.unix.programmer
Subject: Re: How do I tell if STDIN is a PIPE?
Message-ID: <1991May27.022727.9860@leland.Stanford.EDU>
Date: 27 May 91 02:27:27 GMT
Article-I.D.: leland.1991May27.022727.9860
References: <1991May26.172328.713@arizona.edu>
Organization: Sequoia Peripherals, Inc.
Lines: 19

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?
>There must be some system call I can use from a C program.
>My problem is that lseek & fseek won't work with a pipe.
>Therefore, I need to check stdin to see if it is coming from a pipe.

As usual, the best way to see if an operation *would* succeed if you were
to try it is to just go ahead and try it and see if it *did* succeed. If
you seek and it fails and errno is ESPIPE, you know that stdin is 
a pipe.




-- 
Dave Eisen                           dkeisen@leland.Stanford.EDU
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