if((c=getchar())!=EOF)

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As has been said, "if((c=getchar())!=EOF)" is perfectly valid IFF "c" is
declared "int"; NOT if c is a char. Whether char variables are signed or
unsigned, for purposes of comparison or promotion to integer, is explicitly
undefined in C [ref K&R p. 40, p. 183]. This is established and documented.
It is an instance in which the definition of the language is explicitly
ambiguous to allow whatever implementation is more efficient on a particular
machine.
					Bennett Todd
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