getch() and getche() in MSC 4.0

Doug Gwyn gwyn at smoke.BRL.MIL
Sun Oct 23 05:07:34 AEST 1988


In article <10508 at dartvax.Dartmouth.EDU> jalphin at prism.clemson.edu writes:
>	c = toupper(getch());

The problem is almost certainly due to toupper() being implemented as an
"unsafe" macro, i.e. one that evaluates its argument more than once, so
that if the argument has side-effects the result is different from what
a function toupper() would have done.  Obviously getch() has side-effects.



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