Determining Terminal or Window Size (Perl Cookbook, 2nd Edition)

15.4.1. Problem

You need to know the size of the terminal or window. For instance, you want to format text so that it doesn't pass the righthand boundary of the screen.

15.4.2. Solution

Either use the ioctl described in Recipe 12.17, or else use the CPAN module Term::ReadKey:

use Term::ReadKey;

($wchar, $hchar, $wpixels, $hpixels) = GetTerminalSize( );

15.4.3. Discussion

GetTerminalSize returns four elements: the width and height in characters and the width and height in pixels. If the operation is unsupported for the output device (for instance, if output has been redirected to a file), it returns an empty list.

Here's how you'd graph the contents of @values, assuming no value is less than 0:

use Term::ReadKey;

($width) = GetTerminalSize( );
die "You must have at least 10 characters" unless $width >= 10;

$max = 0;
foreach (@values) {
    $max = $_ if $max < $_;
}

$ratio = ($width-10)/$max;          # chars per unit
foreach (@values) {
    printf("%8.1f %s\n", $_, "*" x ($ratio*$_));
}

15.4. Determining Terminal or Window Size

15.4.1. Problem

15.4.2. Solution

15.4.3. Discussion

15.4.4. See Also


15.3. Clearing the Screen		15.5. Changing Text Color