# term_variables 3x 2023-12-23 ncurses 6.4 Library calls

    term_variables(3x)               Library calls              term_variables(3x)

## 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 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.

### 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  is  a  private
           variable.

### Current Terminal Data

           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.

### 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  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.

## NOTES

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

## PORTABILITY

           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.

## SEE ALSO

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

    ncurses 6.4                       2023-12-23                term_variables(3x)