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 20170218).

       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 cer-
     tain 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(3x)
       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 terminal
   should be set and its initialization strings, if defined, must
   be  output.   This can be done by executing the tput init com-
   mand 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(3x)
       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 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 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

       ncurses can be configured to read from  multiple  terminal
       databases.   The  TERMINFO variable overrides the location
       for the default terminal database.  Terminal  descriptions
       (in terminal format) are stored in terminal databases:

       o   Normally  these  are stored in a directory tree, using
           subdirectories named by the first letter of the termi-
           nal names therein.

           This is the scheme used in System V, which legacy Unix
           systems use, and the  TERMINFO  variable  is  used  by
           curses  applications  on those systems to override the
           default location of the terminal database.

       o   If ncurses is built to use hashed databases, then each
           entry  in  this list may be the path of a hashed data-
           base file, e.g.,

             /usr/share/terminfo.db

           rather than

             /usr/share/terminfo/

           The hashed database uses less disk-space and is a lit-
           tle  faster  than  the  directory tree.  However, some
           applications assume the  existence  of  the  directory
           tree,  reading  it directly rather than using the ter-
           minfo library calls.

       o   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.

       o   If the TERMINFO variable begins with "hex:" or "b64:",
           ncurses  uses the remainder of that variable as a com-
           piled terminal description.   You  might  produce  the
           base64 format using infocmp(1m):

             TERMINFO="$(infocmp -0 -Q2 -q)"
             export TERMINFO

           The  compiled description is used if it corresponds to
           the terminal identified by the TERM variable.

       Setting TERMINFO is the simplest, but not the only way  to
       set  location  of the default terminal database.  The com-
       plete list of database locations in order follows:

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

          o   the  location specified by the TERMINFO environment
              variable

          o   $HOME/.terminfo

          o   locations listed in the  TERMINFO_DIRS  environment
              variable

          o   one  or  more  locations 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  locations  to  search for terminal
       descriptions.  Each location in the  list  is  a  terminal
       database as described in the section on the TERMINFO vari-
       able.  The list is separated  by  colons  (i.e.,  ":")  on
       Unix, semicolons on OS/2 EMX.

       There is no corresponding feature in System V terminfo; it
       is an extension developed for ncurses.


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)