terminfo_variables(3NCURSES) Library calls terminfo_variables(3NCURSES)
NAME
SP, acs_map, boolcodes, boolfnames, boolnames, cur_term, numcodes,
numfnames, numnames, strcodes, strfnames, strnames, ttytype - terminfo
global variables
SYNOPSIS
#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[];
DESCRIPTION
This page summarizes variables provided by the curses library's lower-
level terminfo interface. Locate a more complete description in the
terminfo(3NCURSES) manual page.
Depending on ncurses's build-time configuration, these may be actual
variables, or macros (see threads(3NCURSES)) that provide read-only ac-
cess 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-ef-
fect of set_term(3NSES) and delscreen(3NCURSES).
It is possible to save a value of cur_term for subsequent use as a para-
meter to set_term(3NSES) for switching between screens. Alternatively,
one can save the return value from newterm(3NCURSES) or
setupterm(3NCURSES) to reuse in set_term(3NSES).
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 ca-
pability 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 in-
terfaces, setupterm(3NCURSES) copies the terminal name to the array tty-
type.
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(3NCURSES).
The definition of CUR is implementation-dependent, but each terminfo li-
brary defines these names to point into the in-memory description of the
current terminal. For example, in ncurses, the expressions tiget-
str("key_dc") and “CUR Strings[59]” are equivalent.
terminfo and curses
setupterm(3NCURSES) 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 implementa-
tions 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
ncurses(3NCURSES), terminfo(3NCURSES), threads(3NCURSES), terminfo(5)
ncurses 6.5 2024-12-28 terminfo_variables(3NCURSES)
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