Why sysread() + select() only read the first line?

perlmonks12 has asked for the wisdom of the Perl Monks concerning the following question:

Hi I'm using sockets and I'm using to see when there is data to be read, I'm using in this way.

ready = $select->can_read(5);

if (! scalar(@ready)) {

        print "Timed out\n";

} else {

        $sock = $ready[0];

       if (! sysread($ready[0], $msg, 512)) {

                        print "recv failed :$!\n";

        } else {

                    print "$msg";

        }

}
[download]

The code tell me when there is something to be read and it read it and print on the screen. However, it just print the first line, while the answer is much bigger, the first line is like 45 chars + \r\n\r\n and then it has more 300 bytes or so, that are never displayed. However, if I start tcpdump I can see this data coming, but never displayed. What I'm doing wrong? Thanks.

Comment on Why sysread() + select() only read the first line? Download Code

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Re: Why sysread() + select() only read the first line? by ikegami (Patriarch) on May 14, 2010 at 03:05 UTC
Suffering form buffering? Try adding `$\|=1;`	[reply] [d/l]
Re: Why sysread() + select() only read the first line? ($\|) by tye (Sage) on May 14, 2010 at 03:05 UTC
My guess is that you are suffering from buffering (on STDOUT -- sockets aren't buffered). Try adding the following at the top of your code: `$\|= 1;` [download] - tye	[reply] [d/l]
Re: Why sysread() + select() only read the first line? by choroba (Cardinal) on May 13, 2010 at 23:02 UTC
You can search for select line and find poorly documented behaviour of readline() and IO::Select.	[reply]
Re^2: Why sysread() + select() only read the first line? by perlmonks12 (Novice) on May 15, 2010 at 02:26 UTC
Thanks all, it solved the problem.	[reply]