如何在不使用select的情况下检查(查看)Perl中的管道数据的STDIN？

#!/usr/bin/perl

use strict;
use warnings;

my $buffer;
my $bytes_read = sysread(STDIN, $buffer, 1024);

if ($bytes_read) {
    print "Read $bytes_read bytes from STDIN: $buffer\n";
} else {
    print "Error reading from STDIN: $!\n";
}