#!/usr/bin/perl -w
use strict;

my $need_update;
my ($maxcols, $maxrows);

sub getwinsize () {

  sub TIOCGWINSZ () {0x5413}  #from ioctls.ph, which wouldn't include

  return ($maxcols,$maxrows) if $maxcols && $maxrows && !$need_update;

  my $winsize=0;
  my $err = ioctl (STDOUT, TIOCGWINSZ, $winsize);
  if ($err) {
    print "ioctl err: $?\n";
  }

  my ($rows, $cols, $xpix, $ypix) = unpack "s!*", $winsize;

  printf STDERR "r=%d, c=%d, xp=%d, yp=%d\n", $rows//0, $cols//0, 
                                              $xpix//0, $ypix//0;
  $need_update = undef;
  ($maxcols, $maxrows) = ($cols ? $cols : -1, $rows ? $rows : -1);
}

#main

my ($rows,$cols) = getwinsize;

print "rows=$rows, cols=$cols\n";