term_variables(3X) Library calls term_variables(3X)

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

#include <curses.h>
#include <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[];

This page summarizes variables provided by the curses library's low-level terminfo interface. A more complete description is given in the curs_terminfo(3X) manual page.

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

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 is a private variable.

After initializing the curses or terminfo interfaces, the cur_term contains data describing the current terminal. This variable is also set 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, for switching between screens. Alternatively, one can save the return value from newterm or setupterm(3X) to reuse in set_term.

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, although the hash-tables used by the terminfo and termcap functions are not available.

The long terminfo capability names use a “f” (eff) in their names: boolfnames, numfnames, and strfnames.

These are the short names for terminfo capabilities: boolnames, numnames, and strnames.

These are the corresponding names used for termcap descriptions: boolcodes, numcodes, and strcodes.

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 names to the array ttytype.

terminfo Names

In addition to the variables, <term.h> also defines a symbol for each terminfo capability long 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 tigetstr(3X), etc.

The actual definition of CUR depends upon the implementation, but each terminfo library provides these long names defined to point into the current terminal description loaded into memory.

The low-level terminfo interface is initialized using setupterm(3X). The upper-level curses interface uses the low-level terminfo interface, internally.

X/Open Curses does not describe any of these 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 which provide terminfo interfaces add definitions as described in the Terminfo Names section. Most, but not all, base the definition upon the cur_term variable.

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

2024-03-16 ncurses 6.5