Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-lcc!styx!ames!oliveb!sun!gorodish!guy From: guy%gorodish@Sun.COM (Guy Harris) Newsgroups: comp.lang.c Subject: Re: Question about feof() Message-ID: <10715@sun.uucp> Date: Sat, 20-Dec-86 17:26:50 EST Article-I.D.: sun.10715 Posted: Sat Dec 20 17:26:50 1986 Date-Received: Sat, 20-Dec-86 23:43:25 EST References: <31800001@garrity> Sender: news@sun.uucp Lines: 11 Summary: What did you EXPECT it to do? > Could someone out there in net-land explain the reason for the > following behaviour? > > If I change the "r" to a "w", then I get a surprise. The call to > feof() now returns a 0. Why is that? Because it never read from "/dev/null", and hence didn't know that it was at the end of the file. What did you *expect* it to do? Unfortunately, "_filbuf" merely returns EOF if you try to read from something that wasn't open for reading; it doesn't set the error indication, so "ferror" won't tell you that you goofed.