# ncurses 3x

    ncurses(3x)                                                 ncurses(3x)

## 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 rea-
           sonable optimization.  This implementation is "new curses"
           (ncurses) and is the approved replacement for 4.4BSD clas-
           sic  curses,  which has been discontinued.  This describes
           ncurses version 6.0 (patch 20150808).

           The ncurses library emulates the curses library of  System
           V  Release  4  UNIX,  and  XPG4 (X/Open Portability Guide)
           curses (also known as XSI curses).  XSI stands for  X/Open
           System  Interfaces  Extension.   The  ncurses  library  is
           freely redistributable in source form.   Differences  from
           the  SVr4  curses  are summarized under the EXTENSIONS and
           PORTABILITY sections below and described in detail in  the
           respective  EXTENSIONS,  PORTABILITY  and BUGS sections of
           individual man pages.

           The ncurses library also provides many useful  extensions,
           i.e.,  features  which  cannot  be implemented by a simple
           add-on library but which require access to  the  internals
           of the library.

           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 direc-
           tory)  that describe curses actions.  See also the section
           on ALTERNATE CONFIGURATIONS.

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

### Initialization

           The  library uses the locale which the calling program has
           initialized.  That is normally done with setlocale:

                 setlocale(LC_ALL, "");

           If the locale is not initialized, the library assumes that
           characters  are  printable  as in ISO-8859-1, to work with
           certain legacy programs.  You should initialize the locale
           and  not  rely on specific details of the library when the
           locale has not been setup.

           The function initscr or newterm must be called to initial-
           ize the library 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 fol-
           lowing 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 ter-
           minal 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.]

### Datatypes

           The ncurses library permits manipulation  of  data  struc-
           tures,  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 win-
           dows 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 those, 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  dis-
           played.  See curs_pad(3x) for more information.

           In  addition  to  drawing  characters on the screen, video
           attributes and colors may be supported, causing the  char-
           acters  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.

### Environment variables

           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 affect 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 pro-
           gram 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 defini-
           tion 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 avail-
           able.

           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 val-
           ues 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 rou-
           tines prefixed with w require a window argument.  The rou-
           tines prefixed with p require a pad argument.  Those with-
           out 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 WIN-
           DOW.

           Option setting routines require a Boolean flag bf with the
           value TRUE or FALSE; bf is always of type bool.   Most  of
           the  data types used in the library routines, such as WIN-
           DOW, SCREEN, bool, and chtype are defined  in  <curses.h>.
           Types  used for the terminfo routines such as TERMINAL are
           defined in <term.h>.

           This manual page describes functions which may  appear  in
           any  configuration  of  the library.  There are two common
           configurations of the library:

              ncurses
                   the "normal" library, which handles 8-bit  charac-
                   ters.   The  normal (8-bit) library stores charac-
                   ters combined with attributes in chtype data.

                   Attributes alone (no corresponding character)  may
                   be stored in chtype or the equivalent attr_t data.
                   In either case, the data is  stored  in  something
                   like an integer.

                   Each  cell  (row and column) in a WINDOW is stored
                   as a chtype.

              ncursesw
                   the so-called "wide" library, which handles multi-
                   byte characters (see the section on ALTERNATE CON-
                   FIGURATIONS).  The "wide" library includes all  of
                   the  calls  from  the  "normal"  library.  It adds
                   about one third more calls using data types  which
                   store multibyte characters:

                   cchar_t
                        corresponds  to  chtype.   However  it  is  a
                        structure, because more data is  stored  than
                        can  fit into an integer.  The characters are
                        large enough to require a full integer  value
                        -  and  there  may be more than one character
                        per cell.  The video attributes and color are
                        stored in separate fields of the structure.

                        Each  cell  (row  and  column) in a WINDOW is
                        stored as a cchar_t.

                   wchar_t
                        stores a "wide" character.  Like chtype, this
                        may be an integer.

                   wint_t
                        stores  a  wchar_t  or  WEOF  - not the same,
                        though both may have the same size.

                   The "wide" library provides  new  functions  which
                   are   analogous   to  functions  in  the  "normal"
                   library.   There  is  a  naming  convention  which
                   relates  many  of the normal/wide variants: a "_w"
                   is inserted into the name.   For  example,  waddch
                   becomes wadd_wch.

### 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_free_and_exit       curs_memleaks(3x)*
                  _nc_freeall             curs_memleaks(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)*
                  add_wch                 curs_add_wch(3x)
                  add_wchnstr             curs_add_wchstr(3x)
                  add_wchstr              curs_add_wchstr(3x)
                  addch                   curs_addch(3x)
                  addchnstr               curs_addchstr(3x)
                  addchstr                curs_addchstr(3x)
                  addnstr                 curs_addstr(3x)
                  addnwstr                curs_addwstr(3x)
                  addstr                  curs_addstr(3x)
                  addwstr                 curs_addwstr(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)
                  bkgrnd                  curs_bkgrnd(3x)
                  bkgrndset               curs_bkgrnd(3x)
                  border                  curs_border(3x)
                  border_set              curs_border_set(3x)
                  box                     curs_border(3x)
                  box_set                 curs_border_set(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)
                  echo_wchar              curs_add_wch(3x)
                  echochar                curs_addch(3x)
                  endwin                  curs_initscr(3x)
                  erase                   curs_clear(3x)
                  erasechar               curs_termattrs(3x)
                  erasewchar              curs_termattrs(3x)
                  filter                  curs_util(3x)
                  flash                   curs_beep(3x)

                  flushinp                curs_util(3x)
                  get_wch                 curs_get_wch(3x)
                  get_wstr                curs_get_wstr(3x)
                  getattrs                curs_attr(3x)
                  getbegx                 curs_legacy(3x)*
                  getbegy                 curs_legacy(3x)*
                  getbegyx                curs_getyx(3x)
                  getbkgd                 curs_bkgd(3x)
                  getbkgrnd               curs_bkgrnd(3x)
                  getcchar                curs_getcchar(3x)
                  getch                   curs_getch(3x)
                  getcurx                 curs_legacy(3x)*
                  getcury                 curs_legacy(3x)*
                  getmaxx                 curs_legacy(3x)*
                  getmaxy                 curs_legacy(3x)*
                  getmaxyx                curs_getyx(3x)
                  getmouse                curs_mouse(3x)*
                  getn_wstr               curs_get_wstr(3x)
                  getnstr                 curs_getstr(3x)
                  getparx                 curs_legacy(3x)*
                  getpary                 curs_legacy(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)
                  hline_set               curs_border_set(3x)
                  idcok                   curs_outopts(3x)
                  idlok                   curs_outopts(3x)
                  immedok                 curs_outopts(3x)
                  in_wch                  curs_in_wch(3x)
                  in_wchnstr              curs_in_wchstr(3x)
                  in_wchstr               curs_in_wchstr(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)
                  innwstr                 curs_inwstr(3x)
                  ins_nwstr               curs_ins_wstr(3x)
                  ins_wch                 curs_ins_wch(3x)
                  ins_wstr                curs_ins_wstr(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)
                  inwstr                  curs_inwstr(3x)
                  is_cleared              curs_opaque(3x)*
                  is_idcok                curs_opaque(3x)*
                  is_idlok                curs_opaque(3x)*
                  is_immedok              curs_opaque(3x)*
                  is_keypad               curs_opaque(3x)*
                  is_leaveok              curs_opaque(3x)*
                  is_linetouched          curs_touch(3x)
                  is_nodelay              curs_opaque(3x)*

                  is_notimeout            curs_opaque(3x)*
                  is_pad                  curs_opaque(3x)*
                  is_scrollok             curs_opaque(3x)*
                  is_subwin               curs_opaque(3x)*
                  is_syncok               curs_opaque(3x)*
                  is_term_resized         resizeterm(3x)*
                  is_wintouched           curs_touch(3x)
                  isendwin                curs_initscr(3x)
                  key_defined             key_defined(3x)*
                  key_name                curs_util(3x)
                  keybound                keybound(3x)*
                  keyname                 curs_util(3x)
                  keyok                   keyok(3x)*
                  keypad                  curs_inopts(3x)
                  killchar                curs_termattrs(3x)
                  killwchar               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)
                  mvadd_wch               curs_add_wch(3x)
                  mvadd_wchnstr           curs_add_wchstr(3x)
                  mvadd_wchstr            curs_add_wchstr(3x)
                  mvaddch                 curs_addch(3x)
                  mvaddchnstr             curs_addchstr(3x)
                  mvaddchstr              curs_addchstr(3x)
                  mvaddnstr               curs_addstr(3x)
                  mvaddnwstr              curs_addwstr(3x)
                  mvaddstr                curs_addstr(3x)
                  mvaddwstr               curs_addwstr(3x)
                  mvchgat                 curs_attr(3x)
                  mvcur                   curs_terminfo(3x)
                  mvdelch                 curs_delch(3x)
                  mvderwin                curs_window(3x)
                  mvget_wch               curs_get_wch(3x)
                  mvget_wstr              curs_get_wstr(3x)
                  mvgetch                 curs_getch(3x)
                  mvgetn_wstr             curs_get_wstr(3x)
                  mvgetnstr               curs_getstr(3x)
                  mvgetstr                curs_getstr(3x)
                  mvhline                 curs_border(3x)
                  mvhline_set             curs_border_set(3x)
                  mvin_wch                curs_in_wch(3x)
                  mvin_wchnstr            curs_in_wchstr(3x)
                  mvin_wchstr             curs_in_wchstr(3x)
                  mvinch                  curs_inch(3x)
                  mvinchnstr              curs_inchstr(3x)
                  mvinchstr               curs_inchstr(3x)
                  mvinnstr                curs_instr(3x)
                  mvinnwstr               curs_inwstr(3x)
                  mvins_nwstr             curs_ins_wstr(3x)
                  mvins_wch               curs_ins_wch(3x)
                  mvins_wstr              curs_ins_wstr(3x)
                  mvinsch                 curs_insch(3x)
                  mvinsnstr               curs_insstr(3x)
                  mvinsstr                curs_insstr(3x)
                  mvinstr                 curs_instr(3x)
                  mvinwstr                curs_inwstr(3x)
                  mvprintw                curs_printw(3x)
                  mvscanw                 curs_scanw(3x)
                  mvvline                 curs_border(3x)
                  mvvline_set             curs_border_set(3x)

                  mvwadd_wch              curs_add_wch(3x)
                  mvwadd_wchnstr          curs_add_wchstr(3x)
                  mvwadd_wchstr           curs_add_wchstr(3x)
                  mvwaddch                curs_addch(3x)
                  mvwaddchnstr            curs_addchstr(3x)
                  mvwaddchstr             curs_addchstr(3x)
                  mvwaddnstr              curs_addstr(3x)
                  mvwaddnwstr             curs_addwstr(3x)
                  mvwaddstr               curs_addstr(3x)
                  mvwaddwstr              curs_addwstr(3x)
                  mvwchgat                curs_attr(3x)
                  mvwdelch                curs_delch(3x)
                  mvwget_wch              curs_get_wch(3x)
                  mvwget_wstr             curs_get_wstr(3x)
                  mvwgetch                curs_getch(3x)
                  mvwgetn_wstr            curs_get_wstr(3x)
                  mvwgetnstr              curs_getstr(3x)
                  mvwgetstr               curs_getstr(3x)
                  mvwhline                curs_border(3x)
                  mvwhline_set            curs_border_set(3x)
                  mvwin                   curs_window(3x)
                  mvwin_wch               curs_in_wch(3x)
                  mvwin_wchnstr           curs_in_wchstr(3x)
                  mvwin_wchstr            curs_in_wchstr(3x)
                  mvwinch                 curs_inch(3x)
                  mvwinchnstr             curs_inchstr(3x)
                  mvwinchstr              curs_inchstr(3x)
                  mvwinnstr               curs_instr(3x)
                  mvwinnwstr              curs_inwstr(3x)
                  mvwins_nwstr            curs_ins_wstr(3x)
                  mvwins_wch              curs_ins_wch(3x)
                  mvwins_wstr             curs_ins_wstr(3x)
                  mvwinsch                curs_insch(3x)
                  mvwinsnstr              curs_insstr(3x)
                  mvwinsstr               curs_insstr(3x)
                  mvwinstr                curs_instr(3x)
                  mvwinwstr               curs_inwstr(3x)
                  mvwprintw               curs_printw(3x)
                  mvwscanw                curs_scanw(3x)
                  mvwvline                curs_border(3x)
                  mvwvline_set            curs_border_set(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)
                  nofilter                curs_util(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)
                  resize_term             resizeterm(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)
                  setcchar                curs_getcchar(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)
                  term_attrs              curs_termattrs(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)
                  tiparm                  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)
                  unget_wch               curs_get_wch(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)*
                  use_legacy_coding       legacy_coding(3x)*
                  use_tioctl              curs_util(3x)
                  vid_attr                curs_terminfo(3x)
                  vid_puts                curs_terminfo(3x)
                  vidattr                 curs_terminfo(3x)
                  vidputs                 curs_terminfo(3x)
                  vline                   curs_border(3x)
                  vline_set               curs_border_set(3x)
                  vw_printw               curs_printw(3x)
                  vw_scanw                curs_scanw(3x)
                  vwprintw                curs_printw(3x)
                  vwscanw                 curs_scanw(3x)
                  wadd_wch                curs_add_wch(3x)
                  wadd_wchnstr            curs_add_wchstr(3x)
                  wadd_wchstr             curs_add_wchstr(3x)
                  waddch                  curs_addch(3x)
                  waddchnstr              curs_addchstr(3x)
                  waddchstr               curs_addchstr(3x)
                  waddnstr                curs_addstr(3x)
                  waddnwstr               curs_addwstr(3x)
                  waddstr                 curs_addstr(3x)
                  waddwstr                curs_addwstr(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)
                  wbkgrnd                 curs_bkgrnd(3x)
                  wbkgrndset              curs_bkgrnd(3x)
                  wborder                 curs_border(3x)
                  wborder_set             curs_border_set(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)
                  wecho_wchar             curs_add_wch(3x)
                  wechochar               curs_addch(3x)
                  wenclose                curs_mouse(3x)*
                  werase                  curs_clear(3x)
                  wget_wch                curs_get_wch(3x)
                  wget_wstr               curs_get_wstr(3x)
                  wgetbkgrnd              curs_bkgrnd(3x)
                  wgetch                  curs_getch(3x)
                  wgetdelay               curs_opaque(3x)*
                  wgetn_wstr              curs_get_wstr(3x)
                  wgetnstr                curs_getstr(3x)
                  wgetparent              curs_opaque(3x)*
                  wgetscrreg              curs_opaque(3x)*
                  wgetstr                 curs_getstr(3x)
                  whline                  curs_border(3x)

                  whline_set              curs_border_set(3x)
                  win_wch                 curs_in_wch(3x)
                  win_wchnstr             curs_in_wchstr(3x)
                  win_wchstr              curs_in_wchstr(3x)
                  winch                   curs_inch(3x)
                  winchnstr               curs_inchstr(3x)
                  winchstr                curs_inchstr(3x)
                  winnstr                 curs_instr(3x)
                  winnwstr                curs_inwstr(3x)
                  wins_nwstr              curs_ins_wstr(3x)
                  wins_wch                curs_ins_wch(3x)
                  wins_wstr               curs_ins_wstr(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)
                  winwstr                 curs_inwstr(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)
                  wunctrl                 curs_util(3x)
                  wvline                  curs_border(3x)
                  wvline_set              curs_border_set(3x)

## RETURN VALUE

           Routines that return an integer return  ERR  upon  failure
           and  an  integer value other than ERR upon successful com-
           pletion, unless otherwise noted in  the  routine  descrip-
           tions.

           As a general rule, routines check for null pointers passed
           as parameters, and handle this as an error.

           All macros return the  value  of  the  w  version,  except
           setscrreg, wsetscrreg, getyx, getbegyx, and 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 customiz-
           ing the runtime behavior of the ncurses library.  The most
           important ones have been already discussed in detail.

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

           Because this name is also used in development environments
           to represent the C compiler's name, ncurses ignores it  if
           it does not happen to be a single character.

### BAUDRATE

           The  debugging  library  checks  this environment variable
           when the application has redirected output to a file.  The
           variable'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.

### COLUMNS

           Specify the width of the screen in  characters.   Applica-
           tions  running in a windowing environment usually are able
           to obtain the width of the window in which they  are  exe-
           cuting.   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.  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.   However,  setting
           COLUMNS  and/or  LINES  overrides the library's use of the
           screen size obtained from the operating system.

           Either COLUMNS or LINES symbols may be specified  indepen-
           dently.   This  is mainly useful to circumvent legacy mis-
           features of terminal descriptions, e.g., xterm which  com-
           monly 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 all use of external
           environment (but not including system calls) to  determine
           the  screen  size.   Use the use_tioctl function to update
           COLUMNS or LINES to match the screen  size  obtained  from
           system calls or the terminal database.

### 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  net-
           work.   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.

           In  addition to the environment variable, this implementa-
           tion provides a global variable with the same name.   Por-
           table  applications  should  not rely upon the presence of
           ESCDELAY in either form, but setting the environment vari-
           able rather than the global variable does not create prob-
           lems when compiling an application.

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

### NCURSES_ASSUMED_COLORS

           Override the compiled-in assumption  that  the  terminal's
           default   colors   are  white-on-black  (see  default_col-
           ors(3x)).  You may set the foreground and background color
           values  with this environment variable by proving a 2-ele-
           ment list: foreground,background.  For  example,  to  tell
           ncurses  to not assume anything about the colors, set this
           to "-1,-1".  To make it green-on-black, set it  to  "2,0".
           Any  positive  value  from zero to the terminfo max_colors
           value is allowed.

### NCURSES_CONSOLE2

           This applies only to the MinGW port of ncurses.

           The Console2 program's handling of the  Microsoft  Console
           API call CreateConsoleScreenBuffer is defective.  Applica-
           tions which use this will hang.  However, it  is  possible
           to  simulate  the  action  of this call by mapping coordi-
           nates, explicitly saving and restoring the original screen
           contents.   Setting the environment variable NCGDB has the
           same effect.

### NCURSES_GPM_TERMS

           This applies only to ncurses configured  to  use  the  GPM
           interface.

           If  present,  the environment variable is a list of one or
           more terminal names against  which  the  TERM  environment
           variable  is  matched.   Setting it to an empty value dis-
           ables the GPM interface; using the  built-in  support  for
           xterm, etc.

           If  the  environment  variable  is  absent,  ncurses  will
           attempt to open GPM if TERM contains "linux".

### NCURSES_NO_HARD_TABS

           Ncurses may use tabs as part of the cursor movement  opti-
           mization.   In  some  cases,  your terminal driver may not
           handle these properly.  Set this environment  variable  to
           disable  the  feature.  You can also adjust your stty set-
           tings to avoid the problem.  NCURSES_NO_MAGIC_COOKIE  Some
           terminals  use  a magic-cookie feature which requires spe-
           cial  handling  to  make  highlighting  and  other   video
           attributes  display  properly.  You can suppress the high-
           lighting entirely for  these  terminals  by  setting  this
           environment variable.

### 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 environ-
           ment and use curses-based applications.   Terminal  emula-
           tors can duplicate all of the important aspects of a hard-
           ware 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 environment variable to disable
           all but mandatory padding.  Mandatory padding is used as a
           part of special control sequences such as flash.

### NCURSES_NO_SETBUF

           This setting is obsolete.  Before changes

              o   started with 5.9 patch 20120825 and

              o   continued though 5.9 patch 20130126

           ncurses enabled buffered output during  terminal  initial-
           ization.   This  was  done (as in SVr4 curses) for perfor-
           mance reasons.  For testing purposes, both of ncurses  and
           certain  applications,  this  feature  was  made optional.
           Setting the  NCURSES_NO_SETBUF  variable  disabled  output
           buffering,  leaving  the  output  in the original (usually
           line buffered) mode.

           In the current implementation, ncurses  performs  its  own
           buffering  and  does not require this workaround.  It does
           not modify the buffering of the standard output.

           The reason for the change was to  make  the  behavior  for
           interrupts and other signals more robust.  One drawback is
           that certain nonconventional programs would  mix  ordinary
           stdio  calls  with ncurses calls and (usually) work.  This
           is no longer possible  since  ncurses  is  not  using  the
           buffered  standard  output but its own output (to the same
           file descriptor).  As a special case, the low-level  calls
           such  as  putp  still  use the standard output.  But high-
           level curses calls do not.

### NCURSES_NO_UTF8_ACS

           During initialization, the ncurses library checks for spe-
           cial cases where VT100 line-drawing (and the corresponding
           alternate character set  capabilities)  described  in  the
           terminfo are known to be missing.  Specifically, when run-
           ning in a UTF-8 locale, the Linux console emulator and the
           GNU  screen program ignore these.  Ncurses checks the TERM
           environment variable for these.  For other special  cases,
           you  should  set  this  environment  variable.  Doing this
           tells ncurses to use Unicode values  which  correspond  to
           the VT100 line-drawing glyphs.  That works for the special
           cases cited, and is likely to work for terminal emulators.

           When setting this variable, you should set it to a nonzero
           value.   Setting  it  to zero (or to a nonnumber) disables
           the special check for "linux" and "screen".

           As an alternative to  the  environment  variable,  ncurses
           checks  for an extended terminfo capability U8.  This is a
           numeric capability which can  be  compiled  using  tic -x.
           For example

              # linux console, if patched to provide working
              # VT100 shift-in/shift-out, with corresponding font.
              linux-vt100|linux console with VT100 line-graphics,
                      U8#0, use=linux,

              # uxterm with vt100Graphics resource set to false
              xterm-utf8|xterm relying on UTF-8 line-graphics,
                      U8#1, use=xterm,

           The name "U8" is chosen to be two characters, to permit it
           to be used  by  applications  that  use  ncurses'  termcap
           interface.

### NCURSES_TRACE

           During   initialization,  the  ncurses  debugging  library
           checks the NCURSES_TRACE environment variable.  If  it  is
           defined, to a numeric value, ncurses calls the trace func-
           tion, using that value as the argument.

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

           See curs_trace(3x) for more information.

### TERM

           Denotes  your  terminal  type.  Each terminal type is dis-
           tinct, though many are similar.

           TERM is commonly set by terminal emulators to help  appli-
           cations  find  a  workable  terminal description.  Some of
           those  choose  a  popular  approximation,  e.g.,   "ansi",
           "vt100",  "xterm"  rather  than  an exact fit.  Not infre-
           quently, your application will  have  problems  with  that
           approach, e.g., incorrect function-key definitions.

           If  you  set TERM in your environment, it has no effect on
           the operation of the terminal emulator.  It  only  affects
           the  way applications work within the terminal.  Likewise,
           as a general rule (xterm being a rare exception), terminal
           emulators  which  allow you to specify TERM as a parameter
           or configuration value do not  change  their  behavior  to
           match that setting.

### 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 environment variable contains either a  termi-
           nal  description  (with  newlines stripped out), or a file
           name telling where the information  denoted  by  the  TERM
           environment  variable  exists.  In either case, setting it
           directs ncurses to ignore the usual place for this  infor-
           mation, 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:

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

              o   the directory specified by the TERMINFO environment
                  variable

              o   $HOME/.terminfo

              o   directories listed in the TERMINFO_DIRS environment
                  variable

              o   one  or more directories whose names are configured
                  and compiled into the ncurses library, i.e.,

                 o   /usr/local/ncurses/share/ter-
                     minfo:/usr/share/terminfo  (corresponding to the
                     TERMINFO_DIRS variable)

                 o   /usr/share/terminfo (corresponding to  the  TER-
                     MINFO variable)

### TERMINFO_DIRS

           Specifies  a  list  of  directories to search for terminal
           descriptions.  The list is separated by colons (i.e., ":")
           on Unix, semicolons on OS/2 EMX.

           All  of  the  terminal  descriptions are in terminfo form.
           Normally these are stored in a directory tree, using  sub-
           directories  named  by  the  first  letter of the terminal
           names therein.

           If ncurses is built with  a  hashed  database,  then  each
           entry in this list can also be the path of the correspond-
           ing database file.

           If ncurses is built with a  support  for  reading  termcap
           files directly, then an entry in this list may be the path
           of a termcap file.

### TERMPATH

           If TERMCAP does not hold a file name then  ncurses  checks
           the  TERMPATH  environment  variable.   This  is a list of
           filenames separated by spaces or  colons  (i.e.,  ":")  on
           Unix, semicolons on OS/2 EMX.

           If  the  TERMPATH environment variable 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.

## ALTERNATE CONFIGURATIONS

           Several  different  configurations are possible, depending
           on  the  configure  script  options  used  when   building
           ncurses.   There  are a few main options whose effects are
           visible to the applications developer using ncurses:

           --disable-overwrite
                The standard include for ncurses is as noted in  SYN-
                OPSIS:

              #include <curses.h>

                This  option is used to avoid filename conflicts when
                ncurses is not the main implementation of  curses  of
                the  computer.   If  ncurses  is  installed disabling
                overwrite, it puts its  headers  in  a  subdirectory,
                e.g.,

              #include <ncurses/curses.h>

                It  also  omits a symbolic link which would allow you
                to use -lcurses to build executables.

           --enable-widec
                The configure script renames the library and (if  the
                --disable-overwrite  option  is used) puts the header
                files  in  a  different  subdirectory.   All  of  the
                library  names  have  a  "w"  appended to them, i.e.,
                instead of

              -lncurses

                you link with

              -lncursesw

                You must also define _XOPEN_SOURCE_EXTENDED when com-
                piling  for  the  wide-character  library  to use the
                extended (wide-character)  functions.   The  curses.h
                file   which  is  installed  for  the  wide-character
                library is designed to be compatible with the  normal
                library's header.  Only the size of the WINDOW struc-
                ture differs, and very few applications require  more
                than  a  pointer  to  WINDOWs.   If  the  headers are
                installed  allowing  overwrite,  the   wide-character
                library's  headers should be installed last, to allow
                applications to be built using  either  library  from
                the same set of headers.

           --with-pthread
                The configure script renames the library.  All of the
                library names have a "t" appended to them (before any
                "w" added by --enable-widec).

                The  global  variables  such as LINES are replaced by
                macros to allow read-only access.  At the same  time,
                setter-functions  are  provided  to set these values.
                Some applications (very few) may require  changes  to
                work with this convention.

           --with-shared

           --with-normal

           --with-debug

           --with-profile
                The  shared  and normal (static) library names differ
                by their  suffixes,  e.g.,  libncurses.so  and  libn-
                curses.a.   The  debug  and profiling libraries add a
                "_g" and a "_p" to the root names respectively, e.g.,
                libncurses_g.a and libncurses_p.a.

           --with-trace
                The  trace  function  normally  resides  in the debug
                library, but it is sometimes useful to configure this
                in  the  shared  library.   Configure  scripts should
                check for the function's existence rather than assum-
                ing it is always in the debug library.

## FILES

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

## SEE ALSO

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

## EXTENSIONS

           The  ncurses  library  can  be  compiled  with  an  option
           (-DUSE_GETCAP) that falls back to the old-style /etc/term-
           cap 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) key_defined(3x), and keyok(3x) man-
           ual pages for details.

           The ncurses library can exploit the capabilities of termi-
           nals  which  implement the ISO-6429 SGR 39 and SGR 49 con-
           trols, 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  col-
           ored  text  on  a  background  whose color is set indepen-
           dently, providing better  control  over  color  contrasts.
           See the 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 confor-
           mant with XSI Curses.  The EXTENDED XSI Curses functional-
           ity (including color support) is supported.

           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.

           Unlike other implementations, this one  checks  parameters
           such  as  pointers to WINDOW structures to ensure they are
           not null.  The main reason for providing this behavior  is
           to guard against programmer error.  The standard interface
           does not provide a way for the library to tell an applica-
           tion  which  of  several  possible  errors  were detected.
           Relying on this (or some other) extension  will  adversely
           affect the portability of curses applications.

           This implementation also contains several extensions:

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

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

           o   The routines getmouse, mousemask, ungetmouse, mousein-
               terval, 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.

           o   The routine mcprint was not present  in  any  previous
               curses  implementation.  See the curs_print(3x) manual
               page for details.

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

           o   The WINDOW structure's internal details can be  hidden
               from  application  programs.   See curs_opaque(3x) for
               the discussion of is_scrollok, etc.

           o   This implementation can be configured to provide rudi-
               mentary  support for multi-threaded applications.  See
               curs_threads(3x) for details.

           o   This implementation can also be configured to  provide
               a set of functions which improve the ability to manage
               multiple screens.  See curs_sp_funcs(3x) for details.

           In historic curses versions, delays embedded in the  capa-
           bilities cr, ind, cub1, ff and tab activated corresponding
           delay bits in the UNIX tty driver.   In  this  implementa-
           tion,  all  padding  is  done  by sending NUL bytes.  This
           method is slightly more expensive, but narrows the  inter-
           face  to  the  UNIX kernel significantly and increases the
           package's portability correspondingly.

## 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 fea-
           ture 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.

                                                                ncurses(3x)