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 access to curses's state. In either case, applications should
treat them as read-only to avoid confusing the library.
AlternateCharacterSetMapping
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.
CurrentTerminalData
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(3NSES) and delscreen(3NCURSES).
It is possible to save a value of cur_term for subsequent use as a parameter 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).
terminfoLookupTables
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.
TerminalType
A terminal description begins with one or more terminal names separated by “|” (vertical bars). On
initialization of the curses or terminfo interfaces, setupterm(3NCURSES) copies the terminal name to the
array ttytype.
terminfoNames
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 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 “CURStrings[59]” are equivalent.
terminfoandcursessetupterm(3NCURSES) initializes the lower-level terminfo interface. The higher-level curses interface
uses the terminfo interface internally; the symbol SP bridges the cursesSCREEN type with the terminfoTERMINAL type.