#!/usr/bin/perl

use strict;
use warnings;

# input device
my $input = "/dev/dsp1";

# open filehandler
open(my $fh, '<', $input) or die("ERROR open $input ($!)\n");
binmode($fh);

while(1) {
	my $buffer;

	# read one byte
	read($fh, $buffer, 1);

	if(defined($buffer)) {
		# ignore
	}
	else {
		print "nothing to collect\n";
	}
}

close($fh);

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

open my $fh, '<', '/dev/null';
binmode($fh);

my $buffer;

# read one byte
read($fh, $buffer, 1);

if(defined $buffer) {
	print "read something\n";
}
else {
	print "nothing to collect\n";
}

##</code><code>##

#!/usr/bin/perl

use strict;
use warnings;

open my $fh, '<', '/dev/null';
binmode($fh);

my $buffer;

# read one byte
my $r = read($fh, $buffer, 1);

if($r > 0) {
	print "read something\n";
}
else {
	print "nothing to collect\n";
}

close($fh);