usr/doc/curses/intro.2

.sh 1 Variables
.pp
Many variables which are used to describe the terminal environment
are available to the programmer. They are:
.TS
expand;
lw(6m) lw(8n) lw(50n).
type    name    description
_
WINDOW *        curscr  T{
.fi
current version of the screen (terminal screen).
T}
WINDOW *        stdscr  T{
standard screen.  Most updates are usually done here.
T}
char *  Def\*_term      T{
default terminal type if type cannot be determined
T}
bool    My\*_term       T{
use the terminal specification in \fIDef\*_term\fR as terminal,
irrelevant of real terminal type
T}
char *  ttytype T{
full name of the current terminal.
T}
int     LINES   T{
number of lines on the terminal
T}
int     COLS    T{
number of columns on the terminal
T}
int     ERR     T{
error flag returned by routines on a fail.
T}
int     OK      T{
error flag returned by routines when things go right.
T}
.TE
.pp
There are also several
.q #define
constants and types
which are of general usefulness:
.sp
.ev 1
.ta 11n
.(b L
.nf
reg     storage class ``register'' (e.g., \fIreg int i;\fR\|)
bool    boolean type, actually a ``char'' (e.g., \fIbool doneit;\fR\|)
TRUE    boolean ``true'' flag (1).
FALSE   boolean ``false'' flag (0).
.fi
.ev
.)b
.lp