See ioctl, if the return value is true, its not an error.

See also Pack/Unpack Tutorial (aka How the System Stores Data), s!* looks suspicious, what I'd usually do is try every option :)

update: Oh look, this is a perlfaq8 item

How do I get the screen size?

If you have Term::ReadKey module installed from CPAN, you can use it to fetch the width and height in characters and in pixels: 

    use Term::ReadKey;
    ($wchar, $hchar, $wpixels, $hpixels) = GetTerminalSize();

[download]
This is more portable than the raw ioctl, but not as illustrative: 
    require 'sys/ioctl.ph';
    die "no TIOCGWINSZ " unless defined &TIOCGWINSZ;
    open(TTY, "+</dev/tty")                     or die "No tty: $!";
    unless (ioctl(TTY, &TIOCGWINSZ, $winsize='')) {
            die sprintf "$0: ioctl TIOCGWINSZ (%08x: $!)\n", &TIOCGWIN
+SZ;
    }
    ($row, $col, $xpixel, $ypixel) = unpack('S4', $winsize);
    print "(row,col) = ($row,$col)";
    print "  (xpixel,ypixel) = ($xpixel,$ypixel)" if $xpixel || $ypixe
+l;
    print "\n";

[download]

In reply to Re: Failing to get current TTY's rows & columns... by Anonymous Monk
in thread Failing to get current TTY's rows & columns... by perl-diddler

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