Hi, In a nutshell, the IO::Select can_read method doesn't work on MS Windows, afaict.

The demo: 
use warnings;
use strict;
use IO::Select;

open(RD, '<', $0) or die "Can't open RD: $!";

my $s = IO::Select->new();

$s->add(\*RD);

my @r = $s->can_read();
my $cum;

if(@r) {
  # Assign the first 7 lines of this
  # file to $cum (1 byte at a time),
  # and print out $cum
  do { 
    my $byte;
    sysread $r[0], $byte, 1;
    $cum .= $byte;
  } until $cum =~ /new\(\);/;
  print "\n\$cum:\n\n$cum\n";
}
else {
  print "\@r contains no elements\n";
}

[download]
On Cygwin and Linux, as expected, that prints out the first 7 lines of itself (ie the first 7 lines of $0).

But on Windows, it just prints out "@r contains no elements".
This happens because can_read() fails to return anything on Windows - and that's irrespective of the timeout value supplied as an argument to can_read (or even if *no* argument is supplied).

So ... I'm wondering how (on Windows) do we query an IO::Select object in such a way that it returns the same as can_read does on Cygwin/Linux ?

Cheers,
Rob

In reply to [Win32] IO::Select's can_read method by syphilis

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