I don't have linux, but no, I don't think that is the answer.

I think part of the answer is to do error checking correctly like the faq entry

I also think using S4 is part of the answer, not being an expert on pack/unpack and not having a /dev/tty, I can't run any tests.

Hmmm....I'm disappointed that I need to open another file handle and can't get the rows & columns associated with my already open FH, "STDOUT", directly...

Sounds premature if you ask me, avoiding abstractions always involves some growing pains :)

Shouldn't STDIN, STDOUT map to fd[0], fd[1] => /dev/pts/1 on some level?

They do

$ perl -le " print fileno($_) for STDIN, STDOUT, STDERR "
0
1
2
[download]

$ perl -le " print 0+-t $_  for STDIN, STDOUT, STDERR "
1
1
1
[download]

$ perl -le " print 0+-t $_  for STDIN, STDOUT, STDERR "  < NUL
0
1
1
[download]

$ perl -le " print 0+-t $_  for STDIN, STDOUT, STDERR "  < NUL  2> NUL
0
1
0
[download]

$ perl -le " print 0+-t $_  for STDIN, STDOUT, STDERR " > out.txt

$ cat out.txt
1
0
1
[download]

ioctl says you don't need to, the faq item doesn't, and neither does Term::Size::Any

I think part of the answer is to do error checking correctly like the faq entry

See my answer to previous poster -- that's a red herring as well as the unpack format.

What you are missing is:

"I.e. Shouldn't I be able to use some mapping function on STDOUT to get a file descriptor that's suitable for ioctl?

ioctl says you don't need to, the faq item doesn't, and neither does Term::Size::Any

The faq item doesn't use STDOUT. It doesn't show how one would use STDOUT to determine the terminal's size. It opens '/dev/tty' -- ANOTHER file handle -- it doesn't show how to determine the size of the terminal attached to STDOUT.

Of note -- if STDOUT was redirected to a file, then trying to determine its size woudn't return valid values (presumably the ioctl would return an error).

So how would you determine the rows/columns of whatever STDOUT is pointing to (without opening another character device like "/dev/tty")?

Even if you aren't on linux, presumably there's a way to do it on your platform, no? I.e. if you have a 'tty' window, how would you determine the size of the window addressed by 'STDOUT'?

See my answer to previous poster -- that's a red herring as well as the unpack format.

Same guy, and no, the red herring is you're confusing c function ioctl with perl function ioctl

What you are missing is:

No, I didn't miss it. If you redirect STDIN/STDOUT/STDERR, then you need to give ioctl a handle which is connected to tty, so you open your own to /dev/tty, and it works regardless of the state of STDIN/STDOUT/STDERR

Even if you aren't on linux, presumably there's a way to do it on your platform, no? I.e. if you have a 'tty' window, how would you determine the size of the window addressed by 'STDOUT'?

I would use an abstraction like Term::Size::Any, I wouldn't mess around with ioctl

But in all honesty, unless I'm writing some kind of curses program, I would never need to know the size of the terminal