Flex segfaults after reading EOF in `input()` about flex HOT 2 OPEN

I can't find a spot in the docs that explains this behavior clearly. The best hints I could find are in the sections on multiple buffers, yywrap, and EOF rules.

You need an <> rule that calls yyterminate or sets up the next buffer. That rule will take the place of yywrap in your use case.

I'm away from my computer but I'll post an example when I'm back.

from flex.

Thanks for clarifying.

In case it's useful when thinking about the docs, my mental model, when writing what I did, was that when I arrive at EOF using input(), I'm doing so ‘legitimately’ (ie, as opposed to my being illegitimately creative with yyinput, or something like that). It was on that basis that I presumed yywrap would Do The Right Thing, and that when flex subsequently asked for more input from input(), it would be told calmly ‘no’.

Or, put another way, my mental model is that flex is itself using input() to get input, or something equivalent to that, so that I'm working in concert with it if I read from it separately.

If those are bad intuitions, it might be useful for the docs to disabuse the reader fairly explicitly.

from flex.