## NAME

           ncurses - CRT screen handling and optimization package

## SYNOPSIS

           #include <curses.h>

## DESCRIPTION

           The  ncurses  library  routines  give the user a terminal-
           independent method  of  updating  character  screens  with
           reasonable  optimization.   This  implementation  is ``new
           curses'' (ncurses) and is  the  approved  replacement  for
           4.4BSD classic curses, which has been discontinued.

           The  ncurses  routines  emulate  the curses(3x) library of
           System V Release 4 UNIX, and the XPG4 curses standard (XSI
           curses)  but the ncurses library is freely redistributable
           in source form.  Differences  from  the  SVr4  curses  are
           summarized  under  the  EXTENSIONS and BUGS sections below
           and  described  in  detail  in  the  EXTENSIONS  and  BUGS
           sections of individual man pages.

           A  program  using  these  routines must be linked with the
           -lncurses option, or (if it has been generated)  with  the
           debugging  library  -lncurses_g.   (Your system integrator
           may also have installed these libraries  under  the  names
           -lcurses and -lcurses_g.)  The ncurses_g library generates
           trace logs (in  a  file  called  'trace'  in  the  current
           directory) that describe curses actions.

           The  ncurses  package supports: overall screen, window and
           pad manipulation; output  to  windows  and  pads;  reading
           terminal input; control over terminal and curses input and
           output  options;   environment   query   routines;   color
           manipulation;   use   of   soft   label   keys;   terminfo
           capabilities;   and   access   to   low-level    terminal-
           manipulation routines.

           To initialize the routines, the routine initscr or newterm
           must be called before any of the other routines that  deal
           with  windows  and  screens  are used.  The routine endwin
           must be called before exiting.  To get character-at-a-time
           input  without  echoing (most interactive, screen oriented
           programs want this),  the  following  sequence  should  be
           used:

                 initscr(); cbreak(); noecho();

           Most programs would additionally use the sequence:

                 nonl();
                 intrflush(stdscr, FALSE);
                 keypad(stdscr, TRUE);

           Before  a  curses  program  is  run,  the tab stops of the
           terminal should be set and its initialization strings,  if
           defined,  must  be  output.  This can be done by executing
           the tput init command after the shell environment variable
           TERM  has  been  exported.  tset(1) is usually responsible
           for doing this.  [See terminfo(5) for further details.]

           The  ncurses  library   permits   manipulation   of   data
           structures,  called  windows,  which  can be thought of as
           two-dimensional arrays of characters representing  all  or
           part  of  a  CRT  screen.  A default window called stdscr,
           which is the size of the  terminal  screen,  is  supplied.
           Others may be created with newwin.

           Note  that  curses  does  not  handle overlapping windows,
           that's done by the panel(3x) library. This means that  you
           can  either  use  stdscr  or  divide the screen into tiled
           windows and not using stdscr at all. Mixing the  two  will
           result in unpredictable, and undesired, effects.

           Windows are referred to by variables declared as WINDOW *.
           These  data  structures  are  manipulated  with   routines
           described  here and elsewhere in the ncurses manual pages.
           Among which the most basic routines are  move  and  addch.
           More  general versions of these routines are included with
           names beginning with w, allowing the  user  to  specify  a
           window.  The routines not beginning with w affect stdscr.)

           After using routines to manipulate a  window,  refresh  is
           called,  telling curses to make the user's CRT screen look
           like stdscr.  The characters in a window are  actually  of
           type  chtype, (character and attribute data) so that other
           information about the character may also  be  stored  with
           each character.

           Special  windows  called  pads  may  also  be manipulated.
           These are windows which are not constrained to the size of
           the  screen  and  whose  contents  need  not be completely
           displayed.  See curs_pad(3x) for more information.

           In addition to drawing characters  on  the  screen,  video
           attributes  and  colors  may  be  supported,  causing  the
           characters to show up in  such  modes  as  underlined,  in
           reverse  video, or in color on terminals that support such
           display enhancements.   Line  drawing  characters  may  be
           specified  to be output.  On input, curses is also able to
           translate arrow and function  keys  that  transmit  escape
           sequences  into single values.  The video attributes, line
           drawing characters, and input values use names, defined in
           <curses.h>, such as A_REVERSE, ACS_HLINE, and KEY_LEFT.

           If the environment variables LINES and COLUMNS are set, or
           if the program is executing in a window environment,  line
           and  column  information  in the environment will override
           information read by terminfo.  This would effect a program
           running  in an AT&T 630 layer, for example, where the size
           of a screen is changeable (see ENVIRONMENT).

           If the  environment  variable  TERMINFO  is  defined,  any
           program   using   curses   checks  for  a  local  terminal
           definition before checking in  the  standard  place.   For
           example,  if  TERM  is  set  to att4424, then the compiled
           terminal definition is found in

                 /usr/share/terminfo/a/att4424.

           (The a is copied from the first letter of att4424 to avoid
           creation  of  huge  directories.)  However, if TERMINFO is
           set to $HOME/myterms, curses first checks

                 $HOME/myterms/a/att4424,

           and if that fails, it then checks

                 /usr/share/terminfo/a/att4424.

           This is useful for developing experimental definitions  or
           when   write  permission  in  /usr/share/terminfo  is  not
           available.

           The integer  variables  LINES  and  COLS  are  defined  in
           <curses.h>  and will be filled in by initscr with the size
           of the screen.  The constants  TRUE  and  FALSE  have  the
           values 1 and 0, respectively.

           The  curses  routines  also  define  the WINDOW * variable
           curscr which is used for certain low-level operations like
           clearing  and  redrawing a screen containing garbage.  The
           curscr can be used in only a few routines.

       Routine and Argument Names
           Many curses routines  have  two  or  more  versions.   The
           routines  prefixed  with w require a window argument.  The
           routines prefixed with p require a  pad  argument.   Those
           without a prefix generally use stdscr.

           The routines prefixed with mv require a y and x coordinate
           to move to before performing the appropriate action.   The
           mv  routines  imply  a call to move before the call to the
           other routine.  The coordinate y always refers to the  row
           (of  the  window), and x always refers to the column.  The
           upper left-hand corner is always (0,0), not (1,1).

           The routines prefixed with mvw take both a window argument
           and  x  and  y coordinates.  The window argument is always
           specified before the coordinates.

           In each case, win is the window affected, and pad  is  the
           pad  affected;  win  and  pad  are always pointers to type
           WINDOW.

           Option setting routines require a Boolean flag bf with the
           value  TRUE  or  FALSE;  bf  is  always of type bool.  The
           variables ch and attrs below are always  of  type  chtype.
           The  types WINDOW, SCREEN, bool, and chtype are defined in
           <curses.h>.  The type TERMINAL  is  defined  in  <term.h>.
           All other arguments are integers.

       Routine Name Index
           The following table lists each curses routine and the name
           of the manual page on which  it  is  described.   Routines
           flagged  with  `*'  are ncurses-specific, not described by
           XPG4 or present in SVr4.

                  curses Routine Name     Manual Page Name
                  --------------------------------------------
                  COLOR_PAIR              curs_color(3x)
                  PAIR_NUMBER             curs_attr(3x)
                  _nc_tracebits           curs_trace(3x)*
                  _traceattr              curs_trace(3x)*
                  _traceattr2             curs_trace(3x)*
                  _tracechar              curs_trace(3x)*
                  _tracechtype            curs_trace(3x)*
                  _tracechtype2           curs_trace(3x)*
                  _tracedump              curs_trace(3x)*
                  _tracef                 curs_trace(3x)*
                  _tracemouse             curs_trace(3x)*
                  addch                   curs_addch(3x)
                  addchnstr               curs_addchstr(3x)
                  addchstr                curs_addchstr(3x)
                  addnstr                 curs_addstr(3x)
                  addstr                  curs_addstr(3x)
                  assume_default_colors   default_colors(3x)*
                  attr_get                curs_attr(3x)
                  attr_off                curs_attr(3x)
                  attr_on                 curs_attr(3x)
                  attr_set                curs_attr(3x)
                  attroff                 curs_attr(3x)
                  attron                  curs_attr(3x)
                  attrset                 curs_attr(3x)
                  baudrate                curs_termattrs(3x)
                  beep                    curs_beep(3x)
                  bkgd                    curs_bkgd(3x)
                  bkgdset                 curs_bkgd(3x)
                  border                  curs_border(3x)
                  box                     curs_border(3x)
                  can_change_color        curs_color(3x)
                  cbreak                  curs_inopts(3x)
                  chgat                   curs_attr(3x)
                  clear                   curs_clear(3x)

                  clearok                 curs_outopts(3x)
                  clrtobot                curs_clear(3x)
                  clrtoeol                curs_clear(3x)
                  color_content           curs_color(3x)
                  color_set               curs_attr(3x)
                  copywin                 curs_overlay(3x)
                  curs_set                curs_kernel(3x)
                  curses_version          curs_extend(3x)*
                  def_prog_mode           curs_kernel(3x)
                  def_shell_mode          curs_kernel(3x)
                  define_key              define_key(3x)*
                  del_curterm             curs_terminfo(3x)
                  delay_output            curs_util(3x)
                  delch                   curs_delch(3x)
                  deleteln                curs_deleteln(3x)
                  delscreen               curs_initscr(3x)
                  delwin                  curs_window(3x)
                  derwin                  curs_window(3x)
                  doupdate                curs_refresh(3x)
                  dupwin                  curs_window(3x)
                  echo                    curs_inopts(3x)
                  echochar                curs_addch(3x)
                  endwin                  curs_initscr(3x)
                  erase                   curs_clear(3x)
                  erasechar               curs_termattrs(3x)
                  filter                  curs_util(3x)
                  flash                   curs_beep(3x)
                  flushinp                curs_util(3x)
                  getbegyx                curs_getyx(3x)
                  getbkgd                 curs_bkgd(3x)
                  getch                   curs_getch(3x)
                  getmaxyx                curs_getyx(3x)
                  getmouse                curs_mouse(3x)*
                  getnstr                 curs_getstr(3x)
                  getparyx                curs_getyx(3x)
                  getstr                  curs_getstr(3x)
                  getsyx                  curs_kernel(3x)
                  getwin                  curs_util(3x)
                  getyx                   curs_getyx(3x)
                  halfdelay               curs_inopts(3x)
                  has_colors              curs_color(3x)
                  has_ic                  curs_termattrs(3x)
                  has_il                  curs_termattrs(3x)
                  has_key                 curs_getch(3x)*
                  hline                   curs_border(3x)
                  idcok                   curs_outopts(3x)
                  idlok                   curs_outopts(3x)
                  immedok                 curs_outopts(3x)
                  inch                    curs_inch(3x)
                  inchnstr                curs_inchstr(3x)
                  inchstr                 curs_inchstr(3x)
                  init_color              curs_color(3x)
                  init_pair               curs_color(3x)

                  initscr                 curs_initscr(3x)
                  innstr                  curs_instr(3x)
                  insch                   curs_insch(3x)
                  insdelln                curs_deleteln(3x)
                  insertln                curs_deleteln(3x)
                  insnstr                 curs_insstr(3x)
                  insstr                  curs_insstr(3x)
                  instr                   curs_instr(3x)
                  intrflush               curs_inopts(3x)
                  is_linetouched          curs_touch(3x)
                  is_wintouched           curs_touch(3x)
                  isendwin                curs_initscr(3x)
                  keybound                keybound(3x)*
                  keyname                 curs_util(3x)
                  keyok                   keyok(3x)*
                  keypad                  curs_inopts(3x)
                  killchar                curs_termattrs(3x)
                  leaveok                 curs_outopts(3x)
                  longname                curs_termattrs(3x)
                  mcprint                 curs_print(3x)*
                  meta                    curs_inopts(3x)
                  mouse_trafo             curs_mouse(3x)*
                  mouseinterval           curs_mouse(3x)*
                  mousemask               curs_mouse(3x)*
                  move                    curs_move(3x)
                  mvaddch                 curs_addch(3x)
                  mvaddchnstr             curs_addchstr(3x)
                  mvaddchstr              curs_addchstr(3x)
                  mvaddnstr               curs_addstr(3x)
                  mvaddstr                curs_addstr(3x)
                  mvchgat                 curs_attr(3x)
                  mvcur                   curs_terminfo(3x)
                  mvdelch                 curs_delch(3x)
                  mvderwin                curs_window(3x)
                  mvgetch                 curs_getch(3x)
                  mvgetnstr               curs_getstr(3x)
                  mvgetstr                curs_getstr(3x)
                  mvhline                 curs_border(3x)
                  mvinch                  curs_inch(3x)
                  mvinchnstr              curs_inchstr(3x)
                  mvinchstr               curs_inchstr(3x)
                  mvinnstr                curs_instr(3x)
                  mvinsch                 curs_insch(3x)
                  mvinsnstr               curs_insstr(3x)
                  mvinsstr                curs_insstr(3x)
                  mvinstr                 curs_instr(3x)
                  mvprintw                curs_printw(3x)
                  mvscanw                 curs_scanw(3x)
                  mvvline                 curs_border(3x)
                  mvwaddch                curs_addch(3x)
                  mvwaddchnstr            curs_addchstr(3x)
                  mvwaddchstr             curs_addchstr(3x)
                  mvwaddnstr              curs_addstr(3x)

                  mvwaddstr               curs_addstr(3x)
                  mvwchgat                curs_attr(3x)
                  mvwdelch                curs_delch(3x)
                  mvwgetch                curs_getch(3x)
                  mvwgetnstr              curs_getstr(3x)
                  mvwgetstr               curs_getstr(3x)
                  mvwhline                curs_border(3x)
                  mvwin                   curs_window(3x)
                  mvwinch                 curs_inch(3x)
                  mvwinchnstr             curs_inchstr(3x)
                  mvwinchstr              curs_inchstr(3x)
                  mvwinnstr               curs_instr(3x)
                  mvwinsch                curs_insch(3x)
                  mvwinsnstr              curs_insstr(3x)
                  mvwinsstr               curs_insstr(3x)
                  mvwinstr                curs_instr(3x)
                  mvwprintw               curs_printw(3x)
                  mvwscanw                curs_scanw(3x)
                  mvwvline                curs_border(3x)
                  napms                   curs_kernel(3x)
                  newpad                  curs_pad(3x)
                  newterm                 curs_initscr(3x)
                  newwin                  curs_window(3x)
                  nl                      curs_outopts(3x)
                  nocbreak                curs_inopts(3x)
                  nodelay                 curs_inopts(3x)
                  noecho                  curs_inopts(3x)
                  nonl                    curs_outopts(3x)
                  noqiflush               curs_inopts(3x)
                  noraw                   curs_inopts(3x)
                  notimeout               curs_inopts(3x)
                  overlay                 curs_overlay(3x)
                  overwrite               curs_overlay(3x)
                  pair_content            curs_color(3x)
                  pechochar               curs_pad(3x)
                  pnoutrefresh            curs_pad(3x)
                  prefresh                curs_pad(3x)
                  printw                  curs_printw(3x)
                  putp                    curs_terminfo(3x)
                  putwin                  curs_util(3x)
                  qiflush                 curs_inopts(3x)
                  raw                     curs_inopts(3x)
                  redrawwin               curs_refresh(3x)
                  refresh                 curs_refresh(3x)
                  reset_prog_mode         curs_kernel(3x)
                  reset_shell_mode        curs_kernel(3x)
                  resetty                 curs_kernel(3x)
                  resizeterm              resizeterm(3x)*
                  restartterm             curs_terminfo(3x)
                  ripoffline              curs_kernel(3x)
                  savetty                 curs_kernel(3x)
                  scanw                   curs_scanw(3x)
                  scr_dump                curs_scr_dump(3x)

                  scr_init                curs_scr_dump(3x)
                  scr_restore             curs_scr_dump(3x)
                  scr_set                 curs_scr_dump(3x)
                  scrl                    curs_scroll(3x)
                  scroll                  curs_scroll(3x)
                  scrollok                curs_outopts(3x)
                  set_curterm             curs_terminfo(3x)
                  set_term                curs_initscr(3x)
                  setscrreg               curs_outopts(3x)
                  setsyx                  curs_kernel(3x)
                  setterm                 curs_terminfo(3x)
                  setupterm               curs_terminfo(3x)
                  slk_attr                curs_slk(3x)*
                  slk_attr_off            curs_slk(3x)
                  slk_attr_on             curs_slk(3x)
                  slk_attr_set            curs_slk(3x)
                  slk_attroff             curs_slk(3x)
                  slk_attron              curs_slk(3x)
                  slk_attrset             curs_slk(3x)
                  slk_clear               curs_slk(3x)
                  slk_color               curs_slk(3x)
                  slk_init                curs_slk(3x)
                  slk_label               curs_slk(3x)
                  slk_noutrefresh         curs_slk(3x)
                  slk_refresh             curs_slk(3x)
                  slk_restore             curs_slk(3x)
                  slk_set                 curs_slk(3x)
                  slk_touch               curs_slk(3x)
                  standend                curs_attr(3x)
                  standout                curs_attr(3x)
                  start_color             curs_color(3x)
                  subpad                  curs_pad(3x)
                  subwin                  curs_window(3x)
                  syncok                  curs_window(3x)
                  termattrs               curs_termattrs(3x)
                  termname                curs_termattrs(3x)
                  tgetent                 curs_termcap(3x)
                  tgetflag                curs_termcap(3x)
                  tgetnum                 curs_termcap(3x)
                  tgetstr                 curs_termcap(3x)
                  tgoto                   curs_termcap(3x)
                  tigetflag               curs_terminfo(3x)
                  tigetnum                curs_terminfo(3x)
                  tigetstr                curs_terminfo(3x)
                  timeout                 curs_inopts(3x)
                  touchline               curs_touch(3x)
                  touchwin                curs_touch(3x)
                  tparm                   curs_terminfo(3x)
                  tputs                   curs_termcap(3x)
                  tputs                   curs_terminfo(3x)
                  trace                   curs_trace(3x)*
                  typeahead               curs_inopts(3x)
                  unctrl                  curs_util(3x)

                  ungetch                 curs_getch(3x)
                  ungetmouse              curs_mouse(3x)*
                  untouchwin              curs_touch(3x)
                  use_default_colors      default_colors(3x)*
                  use_env                 curs_util(3x)
                  use_extended_names      curs_extend(3x)*
                  vidattr                 curs_terminfo(3x)
                  vidputs                 curs_terminfo(3x)
                  vline                   curs_border(3x)
                  vw_printw               curs_printw(3x)
                  vw_scanw                curs_scanw(3x)
                  vwprintw                curs_printw(3x)
                  vwscanw                 curs_scanw(3x)
                  waddch                  curs_addch(3x)
                  waddchnstr              curs_addchstr(3x)
                  waddchstr               curs_addchstr(3x)
                  waddnstr                curs_addstr(3x)
                  waddstr                 curs_addstr(3x)
                  wattr_get               curs_attr(3x)
                  wattr_off               curs_attr(3x)
                  wattr_on                curs_attr(3x)
                  wattr_set               curs_attr(3x)
                  wattroff                curs_attr(3x)
                  wattron                 curs_attr(3x)
                  wattrset                curs_attr(3x)
                  wbkgd                   curs_bkgd(3x)
                  wbkgdset                curs_bkgd(3x)
                  wborder                 curs_border(3x)
                  wchgat                  curs_attr(3x)
                  wclear                  curs_clear(3x)
                  wclrtobot               curs_clear(3x)
                  wclrtoeol               curs_clear(3x)
                  wcolor_set              curs_attr(3x)
                  wcursyncup              curs_window(3x)
                  wdelch                  curs_delch(3x)
                  wdeleteln               curs_deleteln(3x)
                  wechochar               curs_addch(3x)
                  wenclose                curs_mouse(3x)*
                  werase                  curs_clear(3x)
                  wgetch                  curs_getch(3x)
                  wgetnstr                curs_getstr(3x)
                  wgetstr                 curs_getstr(3x)
                  whline                  curs_border(3x)
                  winch                   curs_inch(3x)
                  winchnstr               curs_inchstr(3x)
                  winchstr                curs_inchstr(3x)
                  winnstr                 curs_instr(3x)
                  winsch                  curs_insch(3x)
                  winsdelln               curs_deleteln(3x)
                  winsertln               curs_deleteln(3x)
                  winsnstr                curs_insstr(3x)
                  winsstr                 curs_insstr(3x)
                  winstr                  curs_instr(3x)

                  wmouse_trafo            curs_mouse(3x)*
                  wmove                   curs_move(3x)
                  wnoutrefresh            curs_refresh(3x)
                  wprintw                 curs_printw(3x)
                  wredrawln               curs_refresh(3x)
                  wrefresh                curs_refresh(3x)
                  wresize                 wresize(3x)*
                  wscanw                  curs_scanw(3x)
                  wscrl                   curs_scroll(3x)
                  wsetscrreg              curs_outopts(3x)
                  wstandend               curs_attr(3x)
                  wstandout               curs_attr(3x)
                  wsyncdown               curs_window(3x)
                  wsyncup                 curs_window(3x)
                  wtimeout                curs_inopts(3x)
                  wtouchln                curs_touch(3x)
                  wvline                  curs_border(3x)

## RETURN VALUE

           Routines that return an integer return  ERR  upon  failure
           and  an  integer  value  other  than  ERR  upon successful
           completion,  unless  otherwise  noted   in   the   routine
           descriptions.

           All  macros  return  the  value  of  the w version, except
           setscrreg, wsetscrreg,  getyx,  getbegyx,  getmaxyx.   The
           return  values  of setscrreg, wsetscrreg, getyx, getbegyx,
           and getmaxyx are undefined (i.e., these should not be used
           as the right-hand side of assignment statements).

           Routines that return pointers return NULL on error.

## ENVIRONMENT

           The   following   environment   symbols   are  useful  for
           customizing the runtime behavior of the  ncurses  library.
           The  most  important  ones  have been already discussed in
           detail.

           BAUDRATE
                The debugging library checks this environment  symbol
                when the application has redirected output to a file.
                The symbol's numeric value is used for the  baudrate.
                If  no value is found ncurses uses 9600.  This allows
                testers to construct repeatable test-cases that  take
                into account costs that depend on baudrate.

           CC   When set, change occurrences of the command_character
                (i.e., the cmdch capability) of the  loaded  terminfo
                entries  to  the  value  of  this  symbol.   Very few
                terminfo entries provide this feature.

           COLUMNS
                Specify  the  width  of  the  screen  in  characters.
                Applications   running  in  a  windowing  environment
                usually are able to obtain the width of the window in
                which  they  are  executing.  If neither the $COLUMNS
                value nor the terminal's screen  size  is  available,
                ncurses  uses  the size which may be specified in the
                terminfo database (i.e., the cols capability).

                It is important that your application use  a  correct
                size  for  the  screen.   However, this is not always
                possible because your application may be running on a
                host  which  does  not honor NAWS (Negotiations About
                Window Size), or because you are temporarily  running
                as another user.

                Either  COLUMNS  or  LINES  symbols  may be specified
                independently.  This is mainly useful  to  circumvent
                legacy  misfeatures  of  terminal descriptions, e.g.,
                xterm which commonly specifies a 65 line screen.  For
                best  results, lines and cols should not be specified
                in a terminal description for terminals which are run
                as emulations.

                Use the use_env function to disable this feature.

           ESCDELAY
                Specifies  the total time, in milliseconds, for which
                ncurses will await  a  character  sequence,  e.g.,  a
                function  key.  The default value, 1000 milliseconds,
                is enough for most  uses.   However,  it  is  made  a
                variable to accommodate unusual applications.

                The most common instance where you may wish to change
                this value is to work with slow hosts, e.g.,  running
                on  a  network.   If  the host cannot read characters
                rapidly enough, it will have the same  effect  as  if
                the  terminal did not send characters rapidly enough.
                The library will still see a timeout.

                Note that  xterm  mouse  events  are  built  up  from
                character sequences received from the xterm.  If your
                application makes heavy use of multiple-clicking, you
                may  wish  to lengthen this default value because the
                timeout applies to the composed multi-click event  as
                well as the individual clicks.

           HOME Tells  ncurses where your home directory is.  That is
                where  it  may  read  and  write  auxiliary  terminal
                descriptions:

                $HOME/.termcap
                $HOME/.terminfo

           LINES
                Like  COLUMNS,  specify  the  height of the screen in
                characters.  See COLUMNS for a detailed  description.

           MOUSE_BUTTONS_123
                This applies only to the OS/2 EMX port.  It specifies
                the order of buttons on the mouse.   OS/2  numbers  a
                3-button mouse inconsistently from other platforms:

                1 = left
                2 = right
                3 = middle.

                This symbol lets you customize the mouse.  The symbol
                must be three numeric digits 1-3 in any order,  e.g.,
                123  or  321.   If  it is not specified, ncurses uses
                132.

           NCURSES_NO_PADDING
                Most of the terminal  descriptions  in  the  terminfo
                database  are  written for real "hardware" terminals.
                Many people use terminal emulators  which  run  in  a
                windowing    environment    and    use   curses-based
                applications.  Terminal emulators can  duplicate  all
                of  the important aspects of a hardware terminal, but
                they do not have the  same  limitations.   The  chief
                limitation of a hardware terminal from the standpoint
                of your application is the  management  of  dataflow,
                i.e.,   timing.    Unless   a  hardware  terminal  is
                interfaced into a terminal concentrator  (which  does
                flow  control),  it (or your application) must manage
                dataflow, preventing overruns.  The cheapest solution
                (no  hardware cost) is for your program to do this by
                pausing  after  operations  that  the  terminal  does
                slowly, such as clearing the display.

                As  a  result,  many terminal descriptions (including
                the vt100) have delay times embedded.  You  may  wish
                to  use  these  descriptions, but not want to pay the
                performance penalty.

                Set the NCURSES_NO_PADDING symbol to disable all  but
                mandatory  padding.   Mandatory  padding is used as a
                part of special control sequences such as flash.

           NCURSES_NO_SETBUF
                Normally  ncurses  enables  buffered  output   during
                terminal  initialization.   This  is done (as in SVr4
                curses)  for  performance   reasons.    For   testing
                purposes,  both  of ncurses and certain applications,
                this  feature  is   made   optional.    Setting   the
                NCURSES_NO_SETBUF variable disables output buffering,
                leaving the output  in  the  original  (usually  line
                buffered) mode.

           NCURSES_TRACE
                During  initialization, the ncurses debugging library
                checks the NCURSES_TRACE symbol.  If it  is  defined,
                to a numeric value, ncurses calls the trace function,
                using that value as the argument.

                The argument values, which are defined  in  curses.h,
                provide  several  types of information.  When running
                with traces enabled, your application will write  the
                file trace to the current directory.

           TERM Denotes  your  terminal  type.  Each terminal type is
                distinct, though many are similar.

           TERMCAP
                If the  ncurses  library  has  been  configured  with
                termcap  support, ncurses will check for a terminal's
                description in termcap form if it is not available in
                the terminfo database.

                The   TERMCAP   symbol  contains  either  a  terminal
                description (with newlines stripped out), or  a  file
                name  telling  where  the  information denoted by the
                TERM symbol  exists.   In  either  case,  setting  it
                directs  ncurses  to  ignore the usual place for this
                information, e.g., /etc/termcap.

           TERMINFO
                Overrides the directory in which ncurses searches for
                your terminal description.  This is the simplest, but
                not the only way to change the list  of  directories.
                The complete list of directories in order follows:

                -  the last directory to which ncurses wrote, if any,
                   is searched first.

                -  the directory specified by the TERMINFO symbol

                -  $HOME/.terminfo

                -  directories listed in the TERMINFO_DIRS symbol

                -  one or more directories whose names are configured
                   and  compiled  into  the  ncurses  library,  e.g.,
                   /usr/share/terminfo

           TERMINFO_DIRS
                Specifies  a  list  of  directories  to  search   for
                terminal  descriptions.   The  list  is  separated by
                colons (i.e., ":").  All of the terminal descriptions
                are  in  terminfo  form,  which  makes a subdirectory
                named for the first  letter  of  the  terminal  names
                therein.

           TERMPATH
                If  TERMCAP  does  not  hold a file name then ncurses
                checks the  TERMPATH  symbol.   This  is  a  list  of
                filenames  separated  by  colons (i.e., ":").  If the
                TERMPATH symbol is not  set,  ncurses  looks  in  the
                files   /etc/termcap,   /usr/share/misc/termcap   and
                $HOME/.termcap, in that order.

           The library may be configured to disregard  the  following
           variables  when  the current user is the superuser (root),
           or if the application uses setuid or  setgid  permissions:
           $TERMINFO, $TERMINFO_DIRS, $TERMPATH, as well as $HOME.

## FILES

           /usr/share/tabset
                directory  containing  initialization  files  for the
                terminal  capability   database   /usr/share/terminfo
                terminal capability database

## SEE ALSO

           terminfo(5)  and  3x  pages  whose names begin "curs_" for
           detailed routine descriptions.

## EXTENSIONS

           The  ncurses  library  can  be  compiled  with  an  option
           (-DUSE_GETCAP)   that   falls   back   to   the  old-style
           /etc/termcap file if the terminal setup code cannot find a
           terminfo entry corresponding to TERM.  Use of this feature
           is not recommended, as it essentially includes  an  entire
           termcap   compiler   in   the  ncurses  startup  code,  at
           significant cost in core and startup cycles.

           The ncurses  library  includes  facilities  for  capturing
           mouse  events  on certain terminals (including xterm). See
           the curs_mouse(3x) manual page for details.

           The ncurses library includes facilities for responding  to
           window  resizing  events,  e.g., when running in an xterm.
           See the resizeterm(3x) and wresize(3x)  manual  pages  for
           details.   In addition, the library may be configured with
           a SIGWINCH handler.

           The ncurses library extends the fixed set of function  key
           capabilities  of  terminals  by  allowing  the application
           designer to define additional key  sequences  at  runtime.
           See  the  define_key(3x)  and  keyok(3x)  manual pages for
           details.

           The  ncurses  library  can  exploit  the  capabilities  of
           terminals  which  implement the ISO-6429 SGR 39 and SGR 49
           controls, which allow an application to reset the terminal
           to  its  original  foreground and background colors.  From
           the users' perspective, the application is  able  to  draw
           colored   text   on   a  background  whose  color  is  set
           independently,  providing  better   control   over   color
           contrasts.  See the use_default_colors(3x) manual page for
           details.
           The ncurses library  includes  a  function  for  directing
           application  output  to a printer attached to the terminal
           device.  See the curs_print(3x) manual page for details.

## PORTABILITY

           The  ncurses  library  is  intended   to   be   BASE-level
           conformant with the XSI Curses standard.  Certain portions
           of the EXTENDED XSI Curses functionality (including  color
           support) are supported.  The following EXTENDED XSI Curses
           calls in support of wide (multibyte)  characters  are  not
           yet   implemented:   add_wch,   add_wchnstr,   add_wchstr,
           addnwstr, addwstr, bkgrnd, bkgrndset, border_set, box_set,
           echo_wchar,   erasewchar,  get_wch,  get_wstr,  getbkgrnd,
           getcchar,  getn_wstr,   getwchtype,   hline_set,   in_wch,
           in_wchnstr,   in_wchstr,   innwstr,   ins_nwstr,  ins_wch,
           ins_wstr,   inwchnstr,   inwchstr,    inwstr,    key_name,
           killwchar,    mvadd_wch,    mvadd_wchnstr,   mvadd_wchstr,
           mvaddnwstr, mvaddwstr, mvget_wch, mvget_wstr, mvgetn_wstr,
           mvhline_set,  mvin_wch, mvinnwstr, mvins_nwstr, mvins_wch,
           mvins_wstr, mvinwchnstr, mvinwchstr, mvinwchstr, mvinwstr,
           mvvline_set,  mvwadd_wch,  mvwadd_wchnstr,  mvwadd_wchstr,
           mvwaddnwstr,    mvwaddwstr,     mvwget_ch,     mvwget_wch,
           mvwget_wstr,    mvwgetn_wstr,   mvwhline_set,   mvwin_wch,
           mvwin_wchnstr,  mvwin_wchstr,  mvwinnwstr,   mvwins_nwstr,
           mvwins_wch,    mvwins_wstr,    mvwinwchnstr.    mvwinwstr,
           mvwvline_set, pecho_wchar, setcchar, slk_wset, term_attrs,
           unget_wch,   vhline_set,  vid_attr,  vid_puts,  vline_set,
           wadd_wch, wadd_wchnstr, wadd_wchstr, waddnwstr,  waddwstr,
           waddwstr,  wbkgrnd,  wbkgrndset,  wbkgrndset, wborder_set,
           wecho_wchar, wecho_wchar, wget_wch, wget_wstr, wgetbkgrnd,
           wgetn_wstr,  whline_set, win_wch, win_wchnstr, win_wchstr,
           winnwstr,  wins_nwstr,  wins_wch,  wins_wstr,  winwchnstr,
           winwchstr, winwstr, wunctrl, wvline_set,

           A  small  number of local differences (that is, individual
           differences between the XSI Curses and ncurses calls)  are
           described  in  PORTABILITY  sections  of  the  library man
           pages.

           The routine has_key is not part of XPG4, nor is it present
           in  SVr4.  See the curs_getch(3x) manual page for details.

           The routine slk_attr is  not  part  of  XPG4,  nor  is  it
           present  in  SVr4.   See  the curs_slk(3x) manual page for
           details.

           The    routines    getmouse,    mousemask,     ungetmouse,
           mouseinterval,  and wenclose relating to mouse interfacing
           are not part of XPG4, nor are they present in  SVr4.   See
           the curs_mouse(3x) manual page for details.

           The routine mcprint was not present in any previous curses
           implementation.  See the curs_print(3x)  manual  page  for
           details.
           The routine wresize is not part of XPG4, nor is it present
           in SVr4.  See the wresize(3x) manual page for details.

           In  historic  curses  versions,  delays  embedded  in  the
           capabilities   cr,   ind,   cub1,  ff  and  tab  activated
           corresponding delay bits in the UNIX tty driver.  In  this
           implementation,  all  padding  is done by NUL sends.  This
           method  is  slightly  more  expensive,  but  narrows   the
           interface  to  the UNIX kernel significantly and increases
           the package's portability correspondingly.

           In the XSI standard and  SVr4  manual  pages,  many  entry
           points have prototype arguments of the for char *const (or
           cchar_t  *const,  or  wchar_t  *const,  or  void  *const).
           Depending  on  one's interpretation of the ANSI C standard
           (see section 3.5.4.1), these declarations are  either  (a)
           meaningless,   or   (b)   meaningless  and  illegal.   The
           declaration const char  *x  is  a  modifiable  pointer  to
           unmodifiable  data,  but char *const x' is an unmodifiable
           pointer to modifiable data.  Given that C passes arguments
           by  value,  <type>  *const  as  a  formal  type is at best
           dubious.   Some  compilers  choke   on   the   prototypes.
           Therefore,  in this implementation, they have been changed
           to const <type> * globally.

## NOTES

           The header  file  <curses.h>  automatically  includes  the
           header files <stdio.h> and <unctrl.h>.

           If  standard  output from a ncurses program is re-directed
           to something which is not a tty, screen  updates  will  be
           directed  to  standard  error.   This  was an undocumented
           feature of AT&T System V Release 3 curses.

## AUTHORS

           Zeyd M. Ben-Halim, Eric  S.  Raymond,  Thomas  E.  Dickey.
           Based on pcurses by Pavel Curtis.