Quick one here. I've tried searching around, but I can't make heads or tails.

If I open a file for reading, open FP, "<", "test.txt"; then the following should loop over each line and stop when <FP> is false: 

while (<FP>) {
   ...
}

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However, what if the file test.txt has a single line in it that is simply "0"? How come the while loop continues? Shouldn't it stop because <FP> returns 0, which is false? My only guess as to why it continues is because <FP> actually returns 0 and a newline character.

From this wonderful resource, it says that the while loop only stops on undef. I can't seem to find official documentation as to why the conditional changes from a Boolean to defined() in the presence of the diamond operator.

In reply to while (<FP>) conditionals by jktstance

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