How it got "broke"...

Chris Torek chris at umcp-cs.UUCP
Wed Oct 22 14:07:39 AEST 1986

In article <1322 at umd5> don at umd5 (Chris Sylvain) writes:
>Why "while( fputc(fgetc(fd), fe) != EOF )" quit working as it
>did under both 2.9BSD and Ultrix 1.2 ...

Chances are it never really worked: fputc(EOF, fe) is likely to
put a meta-DEL into file `fe'.

>1)  At the end of file, fgetc() returns (int) -1.
>2)  fputc() prints (char) -1 and then returns a CHAR not an INT.

Actually, fputc returns (unsigned char)c, which turned EOF to 255.

>Naturally, (int) -1 != (char) -1, so we have a problem.

On Ultrix 1.2 Vaxen and 2.9BSD 11s, (int) -1 *is* equal to
(char) -1.  The code is wrong in the first place; fputc is
not supposed to be handed an EOF.  What it does in such cases
is undefined.
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at

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