Get size of terminal window (rows/columns)

Question

Is there any reliable way of getting the number of columns/rows of the current output terminal window?

I want to retrieve these numbers in a C/C++ program.

I

Answer 1

On GNU/Linux using libtermcap (https://www.gnu.org/software/termutils/manual/termcap-1.3/html_mono/termcap.html) create demo.c:

#include 
#include 
#include 
#include 

static char term_buffer[2048];

void
init_terminal_data (void)
{

  char *termtype = getenv ("TERM");
  int success;

  if (termtype == NULL)
    fprintf (stderr, "Specify a terminal type with `setenv TERM '.\n");

  success = tgetent (term_buffer, termtype);
  if (success < 0)
    fprintf (stderr, "Could not access the termcap data base.\n");
  if (success == 0)
    fprintf (stderr, "Terminal type `%s' is not defined.\n", termtype);
}

int
main ()
{
  init_terminal_data ();
  printf ("Got: Lines: %d, Columns: %d\n", tgetnum ("li"), tgetnum ("co"));
  return 0;
}

Then compile with gcc -o demo.x demo.c -ltermcap and run to give:

$ ./demo.x
Got: Lines: 24, Columns: 80

I doubt this helps much on Windows though, I don't know that platform.

(Some of this code is copied straight from the termcap documentation.)