my $total_bytes_to_read; sysread $sock, $total_bytes_to_read, 20; my $total_bytes_read = 0; my $read_string = ''; while ($total_bytes_read < $total_bytes_to_read) { my $buffer; my $bytes_read = sysread $sock, $buffer, ($total_bytes_to_read - $total_bytes_read); $total_bytes_read += $bytes_read; $read_string .= $buffer; } $total_bytes_to_read == $total_bytes_read or die("Tried to read $total_bytes_to_read bits but only got $total_bytes_read bits\n"); return $read_string;