term_variables(3X)

NAME
SP, acs_map, boolcodes, boolfnames, boolnames, cur_term, numcodes, numfnames, numnames, strcodes, strfnames, strnames, ttytype - terminfo global variables

SYNOPSIS
#include <ncurses/curses.h>
#include <ncurses/term.h>

chtype acs_map[];

SCREEN * SP;

TERMINAL * cur_term;

char ttytype[];

NCURSES_CONST char * const boolcodes[];
NCURSES_CONST char * const boolfnames[];
NCURSES_CONST char * const boolnames[];

NCURSES_CONST char * const numcodes[];
NCURSES_CONST char * const numfnames[];
NCURSES_CONST char * const numnames[];

NCURSES_CONST char * const strcodes[];
NCURSES_CONST char * const strfnames[];
NCURSES_CONST char * const strnames[];

DESCRIPTION
This page summarizes variables provided by the curses library's lower-level terminfo interface. Locate a more complete description in the curs_terminfo(3X) manual page.

Depending on ncurses's build-time configuration, these may be actual variables, or macros (see curs_threads(3X)) that provide read-only access to curses's state. In either case, applications should treat them as read-only to avoid confusing the library.

  Alternate Character Set Mapping
After initializing the curses or terminfo interfaces, the acs_map array holds information used to translate cells with the A_ALTCHARSET video attribute into line-drawing characters.

The encoding of the information in this array has changed periodically. Application developers need only know that it is used for the “ACS_” constants in curses.h.

The comparable data for the wide-character library are not exposed as symbols in the API.

  Current Terminal Data
After initializing the curses or terminfo interfaces, cur_term contains data describing the current terminal. It is also updated as a side effect of set_term(3X) and delscreen(3X).

It is possible to save a value of cur_term for subsequent use as a parameter to set_term(3X) for switching between screens. Alternatively, one can save the return value from newterm(3X) or setupterm(3X) to reuse in set_term(3X).

  terminfo Lookup Tables
The tic(1) and infocmp(1) programs use lookup tables for the long and short names of terminfo capabilities, as well as the corresponding names for termcap capabilities. These are available to other applications, though the hash tables used by the terminfo and termcap functions are not.

terminfo stores capability names in arrays with an “f” (eff) in their names: boolfnames, numfnames, and strfnames. It stores the briefer capability codes in arrays without the “f”: boolnames, numnames, and strnames. The corresponding termcap capability codes are stored in boolcodes, numcodes, and strcodes. terminfo(5) catalogs these.

  Terminal Type
A terminal description begins with one or more terminal names separated by “|” (vertical bars). On initialization of the curses or terminfo interfaces, setupterm(3X) copies the terminal name to the array ttytype.

  terminfo Names
In addition to the variables, term.h also defines a symbol for each terminfo capability name. These are in terms of the symbol CUR, which is defined

        #define CUR ((TERMTYPE *)(cur_term))->

These symbols provide a faster method of accessing terminfo capabilities than using, for example, tigetstr(3X).

The definition of CUR is implementation-dependent, but each terminfo library defines these names to point into the in-memory description of the current terminal. For example, in ncurses, the expressions tigetstr("key_dc") and “CUR Strings[59] ” are equivalent.

  terminfo and curses
setupterm(3X) initializes the lower-level terminfo interface. The higher-level curses interface uses the terminfo interface internally; the symbol SP bridges the curses SCREEN type with the terminfo TERMINAL type.

PORTABILITY
X/Open Curses does not describe any of these symbols except for cur_term. (The inclusion of cur_term appears to be an oversight, since other comparable low-level information is omitted by X/Open.)

Other implementations may have comparable variables. Some implementations provide the variables in their libraries, but omit them from the header files.

All implementations that provide terminfo interfaces add definitions as described in the “terminfo Names” section above. Most, but not all, base the definition upon the cur_term variable.

SEE ALSO
curses(3X), curs_terminfo(3X), curs_threads(3X), terminfo(5)