Is there any advantage ...

That is both easy and difficult to give a straight answer to.

1. I've used variations of that successfully.
2. I've tried using IO::Select with blocking sockets and had mixed success.

   can_read() sometimes (often?) returns true when nothing is available.

   Mixing select with buffered IO seems to give unreliable results. Which might be explained by the notes and warning in perlfunc (or not?).

   Note: on some Unixes, the select(2) system call may report a socket file descriptor as "ready for reading", when actually no data is available, thus a subsequent read blocks. It can be avoided using always the O_NONBLOCK flag on the socket. See select(2) and fcntl(2) for further details.

   WARNING: One should not attempt to mix buffered I/O (like read or <FH>) with select, except as permitted by POSIX, and even then only on POSIX systems. You have to use sysread instead.

   With non-blocking IO, false can_reads are nothing more than an annoyance. With blocking IO, they can be a infinite wait. (Or as it was called in my Mech.Eng days, a 'long wait', which is exactly what the unsuspecting apprentice experienced when he was sent to the stores to get one :)

   Mixing non-blocking and blocking IO is useful. Sometimes you don't want to wait more than a few seconds to discover that the server isn't going to respond, but once it has responded, you're prepared to wait whilst it makes up its mind what it will say next. Using a timed initial read saves waiting forever, but falling back onto the built-in blocking IO and all its conveniences, is useful once the conversation is in progress.

   I simply don't know if IO::Select suffers the same limitations as select, but I suspect that it probaly does.

Essentially, having seen can_read() return true when nothing was available, and had the code enter an infinite read state on several occasions (generally when my ISP decided to timeout my connnection), I'm very shy of using select or IO::Select in conjuction with blocking IO (the diamond operator and friends). Maybe I'm talking out of my a***; maybe I've just been 'unlucky'; but that's my experience.

And you know, one of the definitions of madness is doing the same thing over and over and expecting the outcome to be different. Since I do not consider myself to be mad (that's another strong indicator :), when I get bitten a few times, I tend to get shy.