I'd have thought that it's obvious that sysread blocks if there's no data, but otherwise returns the number of bytes actually read.

Why is that obvious? It isn't mentioned under sysread, or select or in thePOD of IO::Select.

Are all those problems documented somewhere?

Depends what you call 'documented'?

Not that I'm aware of in the Perl documentation beyond perhaps some oblique comments regarding 'legacy' or 'dosish' systems.

The first discussion here at PM that I am aware of, and the basis of whatever I have discovered is Non blocking socket open. For a more complete list of the posts that mention the problems you could try google

Are there any modules which mitigate that situation?

None that I am aware of.

If so, is there any reason why IO::Select, IO::Handle, etc can't be told to use them?

See (tye)Re: Non blocking socket open

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

In reply to Re^8: How to make sysread timeout by BrowserUk
in thread How to make sysread timeout by redss

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