Get Terminal Width and Height, Pure Perl

[James Edward Gray II]

Okay, I have a terminal program I need to get the width and height for.
I have a very good reason needing to do it with a base 5.8 Perl
install, if at all possible. Unfortunately, that rules out the super
easy Term::ReadKey CPAN module.

(Side note: I do have Term::ReadKey installed and am very aware of how
wonderful it is. In fact, why isn't this a standard module??? I just
can't count on it being on the box this program will be run on. I'll
fight that fight if I have to, but first I thought I would check for
another option.)

So my question is, is there a "Pure Perl" way to fetch the terminal
columns and rows?

Thanks.

James

[Charles K. Clarkson]

James Edward Gray II <james@grayproductions.net> wrote:
:
: So my question is, is there a "Pure Perl" way to fetch
: the terminal columns and rows?


I took a look at the source of Term::ReadKey and it
seemed to be pure perl. Are you sure it's not? If it is,
you could use it as a guide to write your own sub. Or,
if you're allowed to install multiple files, you could
include this module in your package.


HTH,

Charles K. Clarkson
--
Head Bottle Washer,
Clarkson Energy Homes, Inc.
Mobile Home Specialists
254 968-8328

[James Edward Gray II]

On Dec 15, 2003, at 10:51 AM, Charles K. Clarkson wrote:

> James Edward Gray II <james@grayproductions.net> wrote:
> :
> : So my question is, is there a "Pure Perl" way to fetch
> : the terminal columns and rows?
>
>
> I took a look at the source of Term::ReadKey and it
> seemed to be pure perl. Are you sure it's not?

Haven't got a clue, to tell the truth! <laughs>

I assumed it was not, for two reasons. One, the POD says,
"Term::ReadKey is a compiled perl module..." and that ugly compiled
word in there scared me. And two, I can't see where the function calls
at the beginning of GetTerminalSize() are coming from
(termsizeoptions(), GetTermSizeVIO(), GetTermSizeGWINSZ(),
GetTermSizeGSIZE(), GetTermSizeWin32()).

I also just had the thought to go check the CPAN's listing. It said
'Rdcf?' under the DSLIP column. I'm pretty sure that middle 'c' in
there means it's written in C and Perl. I know how dangerous
assumptions are though, especially mine, and I won't be surprised if
I'm wrong.

> If it is, you could use it as a guide to write your own sub. Or,
> if you're allowed to install multiple files, you could
> include this module in your package.

I did try to look at the module, but as you can see, I can't tell what
it's doing.

Finally, I can only use the include it trick if it is indeed pure Perl,
right?

Thanks for all the good ideas. I did try them.

James

[Bob Showalter]

James Edward Gray II wrote:

> On Dec 15, 2003, at 10:51 AM, Charles K. Clarkson wrote:
>

> > James Edward Gray II <james@grayproductions.net> wrote:

> > >
> > > So my question is, is there a "Pure Perl" way to fetch
> > > the terminal columns and rows?

> >
> >
> > I took a look at the source of Term::ReadKey and it
> > seemed to be pure perl. Are you sure it's not?

>
> Haven't got a clue, to tell the truth! <laughs>
>
> I assumed it was not, for two reasons. One, the POD says,
> "Term::ReadKey is a compiled perl module..." and that ugly compiled
> word in there scared me. And two, I can't see where the
> function calls
> at the beginning of GetTerminalSize() are coming from
> (termsizeoptions(), GetTermSizeVIO(), GetTermSizeGWINSZ(),
> GetTermSizeGSIZE(), GetTermSizeWin32()).
>
> I also just had the thought to go check the CPAN's listing. It said
> 'Rdcf?' under the DSLIP column. I'm pretty sure that middle 'c' in
> there means it's written in C and Perl. I know how dangerous
> assumptions are though, especially mine, and I won't be surprised if
> I'm wrong.

You're right, it's not a pure perl module. The "bootstrap" statement around
line 240 gives it away as well.

>

> > If it is, you could use it as a guide to write your own sub. Or,
> > if you're allowed to install multiple files, you could
> > include this module in your package.

>
> I did try to look at the module, but as you can see, I can't
> tell what
> it's doing.

It's trying to make the process platform-independent, which is rather
tricky.

You might be able to get away with something as simple as querying the LINES
and COLUMNS environment variables. Or use the output from 'tput lines' and
'tput columns'. It all depends on your platform...

[Steven Kreuzer]

>> You might be able to get away with something as simple as querying
the

>> LINES and COLUMNS environment variables. Or use the output from 'tput
>> lines' and 'tput columns'. It all depends on your platform...

Actually, its tput cols

Steven Kreuzer
Linux Systems Administrator
Etagon, Inc
W: 646.728.0656
F: 646.728.0607
E: [email]steven_kreuzer@etagon.com[/email]

[Clifton Wood]

In article <8A7DF9E1-2F1C-11D8-B912-000A95BA45F8@grayproductions.net>,
James Edward Gray II <james@grayproductions.net> wrote:

> Okay, I have a terminal program I need to get the width and height for.
> I have a very good reason needing to do it with a base 5.8 Perl
> install, if at all possible. Unfortunately, that rules out the super
> easy Term::ReadKey CPAN module.
>
> (Side note: I do have Term::ReadKey installed and am very aware of how
> wonderful it is. In fact, why isn't this a standard module??? I just
> can't count on it being on the box this program will be run on. I'll
> fight that fight if I have to, but first I thought I would check for
> another option.)
>
> So my question is, is there a "Pure Perl" way to fetch the terminal
> columns and rows?

Would you be adverse to parsing output from a unix command?

use strict;
my ($rows, $cols);
$data = `stty -a`;
if ($data =~ /rows (\d+)\; columns (\d+)/) {
($rows, $cols) = ($1, $2);
} else {
print "No match.\n";
}

Of course, this is NOT pure Perl, but stty exists on most systems
so this should be *fairly* reliable. At the very least, it may
hold you until you can find a better solution.

- C

[Unregistered]

use Term::ReadKey qw(GetTerminalSize);

sub get_term_cols {
    my $cols = ((GetTerminalSize())[0]); # cols = 0; lines = 1
    $cols and return $cols;

    # alternative:
    -f "/bin/tput" or die("/bin/tput: command not found..");
    open( my $OH, '-|', "/bin/tput cols" ) or die($!);
    chomp(($cols) = <$OH>);
    close($OH) or die($!);
    return $cols
}
print "Columns on your terminal: ".get_term_cols()."\n";