Perl：将一个字节加上STDIN传递给另一个命令

use Strict;
use warnings;

use IO::SELEct qw( );    
BEGIN { require 'sys/ioctl.ph'; }

sub fionread {
    my $sz = pack('L',0);
    return unless ioctl($_[0],FIONREAD,$sz);
    return unpack('L',$sz);
}

# Wait until it's known whether the handle has data to read or has reached EOF.
IO::SELEct->new(\*STDIN)->can_read();

if (fionread(\*STDIN)) {
    system('wc');
    # check for errors
}

这应该可以非常容易地移植到UNIX和类UNIX平台上.