How do I tell if STDIN is a PIPE?

[Dave Eisen]

In article <1991May26.172328.713 at arizona.edu> jjr at 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 at leland.Stanford.EDU
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