Would you feel better about (($a|$b|$c|$d) >> 8) == 0? The intent is to check that each component is one byte, and bitwise or-ing them is consistent with the bit-fiddling nature of what's being tested.
If 256 weren't a power of two, there wouldn't even be a presumption that it might work.
It's clear that you didn't see this as a bit-fiddling scenario, but it is. What, after all, is an IP? It's a four-byte string, translated into human-readable form.
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In reply to Re: Re: Can you spot the problem? by Roy Johnson
in thread Can you spot the problem? by dws

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