# ncurses

## NAME



           **ncurses** - CRT screen handling and optimization package
    


## SYNOPSIS



           **#include <curses.h>**
    


## DESCRIPTION



           The **ncurses** library routines give the user a terminal-independent
           method of updating character screens with reasonable optimization.
           This implementation is “new curses” (ncurses) and is the approved
           replacement for 4.4BSD classic curses, which has been
           discontinued.  This describes **ncurses** version
           @NCURSES_MAJOR@.@NCURSES_MINOR@ (patch @NCURSES_PATCH@).
    
           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 directory) 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 terminal input;
           control over terminal and **curses** input and output options;
           environment query routines; color manipulation; use of soft label
           keys; terminfo capabilities; and access to low-level terminal-
           manipulation routines.
    
       **Initialization**
           The library uses the locale which the calling program has
           initialized.  That is normally done with setlocale(3):
    
               **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 initialize 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 following
           sequence should be used:
    
               **initscr(); cbreak(); noecho();**
    
           Most programs would additionally use the sequence:
    
               **intrflush(stdscr, FALSE);**
               **keypad(stdscr, TRUE);**
    
           Before a **curses** program is run, the tab stops of the terminal
           should be set and its initialization strings, if defined, must be
           output.  This can be done by executing the **tput init** command after
           the shell environment variable **TERM** has been exported.  tset(1) is
           usually responsible for doing this.  [See terminfo(5) for further
           details.]
    
       **Datatypes**
           The **ncurses** library permits manipulation of data structures,
           called _windows_ , which can be thought of as two-dimensional arrays
           of characters representing all or part of a CRT screen.  A default
           window called **stdscr** , which is the size of the terminal screen, is
           supplied.  Others may be created with **newwin**.
    
           Note that **curses** does not handle overlapping windows, that's done
           by the **panel**(3X) library.  This means that you can either use
           **stdscr** or divide the screen into tiled windows and not using
           **stdscr** at all.  Mixing the two will result in unpredictable, and
           undesired, effects.
    
           Windows are referred to by variables declared as **WINDOW ***.  These
           data structures are manipulated with routines described here and
           elsewhere in the **ncurses** manual pages.  Among 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 displayed.  See **curs_pad**(3X)
           for more information.
    
           In addition to drawing characters on the screen, video attributes
           and colors may be supported, causing the characters to show up in
           such modes as underlined, in reverse video, or in color on
           terminals that support such display enhancements.  Line drawing
           characters may be specified to be output.  On input, **curses** is
           also able to translate arrow and function keys that transmit
           escape sequences into single values.  The video attributes, line
           drawing characters, and input values use names, defined in
           **< curses.h>**, such as **A_REVERSE** , **ACS_HLINE** , and **KEY_LEFT**.
    
       **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 program using
           **curses** checks for a local terminal definition before checking in
           the standard place.  For example, if **TERM** is set to **att4424** , then
           the compiled terminal definition is found in
    
               **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
    
               **terminfo/a/att4424**.
    
           This is useful for developing experimental definitions or when
           write permission in **terminfo** is not available.
    
           The integer variables **LINES** and **COLS** are defined in **< curses.h> **and
           will be filled in by **initscr** with the size of the screen.  The
           constants **TRUE** and **FALSE** have the values **1** and **0** , respectively.
    
           The **curses** routines also define the **WINDOW *** variable **curscr** which
           is used for certain low-level operations like clearing and
           redrawing a screen containing garbage.  The **curscr** can be used in
           only a few routines.
    
       **Routine and Argument Names**
           Many **curses** routines have two or more versions.  The routines
           prefixed with _w_ require a window argument.  The routines prefixed
           with _p_ require a pad argument.  Those without a prefix generally
           use **stdscr**.
    
           The routines prefixed with **mv** require a _y_ and _x_ coordinate to move
           to before performing the appropriate action.  The **mv** routines
           imply a call to **move** before the call to the other routine.  The
           coordinate _y_ always refers to the row (of the window), and _x_
           always refers to the column.  The upper left-hand corner is always
           (0,0), not (1,1).
    
           The routines prefixed with **mvw** take both a window argument and _x_
           and _y_ coordinates.  The window argument is always specified before
           the coordinates.
    
           In each case, _win_ is the window affected, and _pad_ is the pad
           affected; _win_ and _pad_ are always pointers to type **WINDOW**.
    
           Option setting routines require a Boolean flag _bf_ with the value
           **TRUE** or **FALSE** ; _bf_ is always of type **bool**.  Most of the data types
           used in the library routines, such as **WINDOW** , **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 characters.  The
                   normal (8-bit) library stores characters 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 multibyte
                   characters (see the section on **ALTERNATE CONFIGURATIONS**).
                   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**.
    
                        The **setcchar**(3X) and **getcchar**(3X) functions store and
                        retrieve the data from a **cchar_t** structure.
    
                   **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 the **curses** routines provided in the
           “normal” and “wide” libraries and the names of the manual pages on
           which they are 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)
                      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)
                      alloc_pair               **new_pair**(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_trace             **curs_trace**(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)
                      exit_curses              **curs_memleaks**(3X)*
                      exit_terminfo            **curs_memleaks**(3X)*
                      extended_color_content   **curs_color**(3X)*
                      extended_pair_content    **curs_color**(3X)*
                      extended_slk_color       **curs_slk**(3X)*
                      filter                   **curs_util**(3X)
                      find_pair                **new_pair**(3X)*
                      flash                    **curs_beep**(3X)
                      flushinp                 **curs_util**(3X)
                      free_pair                **new_pair**(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)*
                      has_mouse                **curs_mouse**(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_extended_color      **curs_color**(3X)*
                      init_extended_pair       **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_inopts**(3X)
                      nocbreak                 **curs_inopts**(3X)
                      nodelay                  **curs_inopts**(3X)
                      noecho                   **curs_inopts**(3X)
                      nofilter                 **curs_util**(3X)*
                      nonl                     **curs_inopts**(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)
                      pecho_wchar              **curs_pad**(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_color_pairs        **curs_color**(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)
                      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)
                      slk_wset                 **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)
                      timeout                  **curs_inopts**(3X)
                      tiparm                   **curs_terminfo**(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)
    
           Depending on the configuration, additional sets of functions may
           be available:
    
              **curs_memleaks**(3X) - curses memory-leak checking
    
              **curs_sp_funcs**(3X) - curses screen-pointer extension
    
              **curs_threads**(3X) - curses thread support
    
              **curs_trace**(3X) - curses debugging routines
    


## RETURN VALUE



           Routines that return an integer return **ERR** upon failure and an
           integer value other than **ERR** upon successful completion, unless
           otherwise noted in the routine descriptions.
    
           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).
    
           Functions with a “mv” prefix first perform a cursor movement using
           **wmove** , and return an error if the position is outside the window,
           or if the window pointer is null.  Most “mv”-prefixed functions
           (except variadic functions such as **mvprintw**) are provided both as
           macros and functions.
    
           Routines that return pointers return **NULL** on error.
    


## ENVIRONMENT



           The following environment symbols are useful for customizing the
           runtime behavior of the **ncurses** library.  The most important ones
           have been already discussed in detail.
    
       **CC command-character**
           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.  Applications
           running in a windowing environment usually are able to obtain the
           width of the window in which they are executing.  If neither the
           **COLUMNS** value nor the terminal's screen size is available, **ncurses**
           uses the size which may be specified in the terminfo database
           (i.e., the **cols** capability).
    
           It is important that your application use a correct size for the
           screen.  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 independently.
           This is mainly useful to circumvent legacy misfeatures of terminal
           descriptions, e.g., xterm which commonly specifies a 65 line
           screen.  For best results, **lines** and **cols** should not be specified
           in a terminal description for terminals which are run as
           emulations.
    
           Use the **use_env** function to disable 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 network.  If the
           host cannot read characters rapidly enough, it will have the same
           effect as if the terminal did not send characters rapidly enough.
           The library will still see a timeout.
    
           Note that xterm mouse events are built up from character sequences
           received from the xterm.  If your application makes heavy use of
           multiple-clicking, you may wish to lengthen this default value
           because the timeout applies to the composed multi-click event as
           well as the individual clicks.
    
           In addition to the environment variable, this implementation
           provides a global variable with the same name.  Portable
           applications should not rely upon the presence of ESCDELAY in
           either form, but setting the environment variable rather than the
           global variable does not create problems 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 characters.  See
           COLUMNS for a detailed description.
    
       **MOUSE_BUTTONS_123**
           This applies only to the OS/2 EMX port.  It specifies the order of
           buttons on the mouse.  OS/2 numbers a 3-button mouse
           inconsistently from other platforms:
    
               1 = left
               2 = right
               3 = middle.
    
           This 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_colors**(3X)).  You may set
           the foreground and background color values with this environment
           variable by proving a 2-element 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.  Applications which use
           this will hang.  However, it is possible to simulate the action of
           this call by mapping coordinates, 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 disables 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 optimization.
           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(1) settings to avoid the problem.
    
       **NCURSES_NO_MAGIC_COOKIE**
           Some terminals use a magic-cookie feature which requires special
           handling to make highlighting and other video attributes display
           properly.  You can suppress the highlighting 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 environment and use curses-
           based applications.  Terminal emulators can duplicate all of the
           important aspects of a hardware terminal, but they do not have the
           same limitations.  The chief limitation of a hardware terminal
           from the standpoint of your application is the management of
           dataflow, i.e., timing.  Unless a hardware terminal is interfaced
           into a terminal concentrator (which does flow control), it (or
           your application) must manage dataflow, preventing overruns.  The
           cheapest solution (no hardware cost) is for your program to do
           this by pausing after operations that the terminal does slowly,
           such as clearing the display.
    
           As a result, many terminal descriptions (including the vt100) have
           delay times embedded.  You may wish to use these descriptions, but
           not want to pay the performance penalty.
    
           Set the NCURSES_NO_PADDING 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
    
              •   started with 5.9 patch 20120825 and
    
              •   continued though 5.9 patch 20130126
    
           **ncurses** enabled buffered output during terminal initialization.
           This was done (as in SVr4 curses) for performance 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 special
           cases where VT100 line-drawing (and the corresponding alternate
           character set capabilities) described in the terminfo are known to
           be missing.  Specifically, when running 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** function, using that value
           as the argument.
    
           The argument values, which are defined in **curses.h** , provide
           several types of information.  When running with traces enabled,
           your application will write the file **trace** to the current
           directory.
    
           See **curs_trace**(3X) for more information.
    
       **TERM**
           Denotes your terminal type.  Each terminal type is distinct,
           though many are similar.
    
           **TERM** is commonly set by terminal emulators to help applications
           find a workable terminal description.  Some of those choose a
           popular approximation, e.g., “ansi”, “vt100”, “xterm” rather than
           an exact fit.  Not infrequently, 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**(1) 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 terminal
           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 information, 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:
    
           •   Normally these are stored in a directory tree, using
               subdirectories named by the first letter of the terminal 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.
    
           •   If **ncurses** is built to use hashed databases, then each entry
               in this list may be the path of a hashed database file, e.g.,
    
                   /usr/share/terminfo.db
    
               rather than
    
                   /usr/share/terminfo/
    
               The hashed database uses less disk-space and is a little
               faster than the directory tree.  However, some applications
               assume the existence of the directory tree, reading it
               directly rather than using the terminfo library calls.
    
           •   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.
    
           •   If the **TERMINFO** variable begins with “hex:” or “b64:”, **ncurses**
               uses the remainder of that variable as a compiled 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 complete list of
           database locations in order follows:
    
              •   the last terminal database to which **ncurses** wrote, if any,
                  is searched first
    
              •   the location specified by the TERMINFO environment variable
    
              •   $HOME/.terminfo
    
              •   locations listed in the TERMINFO_DIRS environment variable
    
              •   one or more locations whose names are configured and
                  compiled into the ncurses library, i.e.,
    
                 •   @TERMINFO_DIRS@ (corresponding to the TERMINFO_DIRS
                     variable)
    
                 •   terminfo (corresponding to the TERMINFO 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** variable.  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 **SYNOPSIS** :
    
                    **#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 enable the wide-character features in the
                header file when compiling for the wide-character library to
                use the extended (wide-character) functions.  The symbol
                which enables these features has changed since XSI Curses,
                Issue 4:
    
                •   Originally, the wide-character feature required the
                    symbol **_XOPEN_SOURCE_EXTENDED** but that was only valid for
                    XPG4 (1996).
    
                •   Later, that was deemed conflicting with **_XOPEN_SOURCE**
                    defined to 500.
    
                •   As of mid-2018, none of the features in this
                    implementation require a **_XOPEN_SOURCE** feature greater
                    than 600.  However, X/Open Curses, Issue 7 (2009)
                    recommends defining it to 700.
    
                •   Alternatively, you can enable the feature by defining
                    **NCURSES_WIDECHAR** with the caveat that some other header
                    file than **curses.h** may require a specific value for
                    **_XOPEN_SOURCE**(or a system-specific symbol).
    
                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** structure
                differs, and very few applications require more than a
                pointer to **WINDOW** s.
    
                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 **libncurses.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-termlib
                Low-level functions which do not depend upon whether the
                library supports wide-characters, are provided in the tinfo
                library.
    
                By doing this, it is possible to share the tinfo library
                between wide/normal configurations as well as reduce the size
                of the library when only low-level functions are needed.
    
                Those functions are described in these pages:
    
                •   **curs_extend**(3X) - miscellaneous curses extensions
    
                •   **curs_inopts**(3X) - **curses** input options
    
                •   **curs_kernel**(3X) - low-level **curses** routines
    
                •   **curs_termattrs**(3X) - **curses** environment query routines
    
                •   **curs_termcap**(3X) - **curses** emulation of termcap
    
                •   **curs_terminfo**(3X) - **curses** interfaces to terminfo
                    database
    
                •   **curs_util**(3X) - miscellaneous **curses** utility routines
    
           --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 assuming it is always in the debug
                library.
    


## FILES



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


## EXTENSIONS



           The **ncurses** library can be compiled with an option (**-DUSE_GETCAP**)
           that falls back to the old-style /etc/termcap file if the terminal
           setup code cannot find a terminfo entry corresponding to **TERM**.
           Use of this feature is not recommended, as it essentially includes
           an entire termcap compiler in the **ncurses** startup code, at
           significant cost in core and startup cycles.
    
           The **ncurses** library includes facilities for capturing mouse events
           on certain terminals (including xterm).  See the **curs_mouse**(3X)
           manual page for details.
    
           The **ncurses** library includes facilities for responding to window
           resizing events, e.g., when running in an xterm.  See the
           **resizeterm**(3X) and **wresize**(3X) manual pages for details.  In
           addition, the library may be configured with a **SIGWINCH** handler.
    
           The **ncurses** library extends the fixed set of function key
           capabilities of terminals by allowing the application designer to
           define additional key sequences at runtime.  See the
           **define_key**(3X) **key_defined**(3X), and **keyok**(3X) manual pages for
           details.
    
           The **ncurses** library can exploit the capabilities of terminals
           which implement the ISO-6429 SGR 39 and SGR 49 controls, which
           allow an application to reset the terminal to its original
           foreground and background colors.  From the users' perspective,
           the application is able to draw colored text on a background whose
           color is set independently, providing better control over color
           contrasts.  See the **default_colors**(3X) manual page for details.
    
           The **ncurses** library includes a function for directing application
           output to a printer attached to the terminal device.  See the
           **curs_print**(3X) manual page for details.
    


## PORTABILITY



           The **ncurses** library is intended to be BASE-level conformant with
           XSI Curses.  The EXTENDED XSI Curses functionality (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.
    
       **Error checking**
           In many cases, X/Open Curses is vague about error conditions,
           omitting some of the SVr4 documentation.
    
           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 application which of several possible
           errors were detected.  Relying on this (or some other) extension
           will adversely affect the portability of curses applications.
    
       **Extensions versus portability**
           Most of the extensions provided by ncurses have not been
           standardized.  Some have been incorporated into other
           implementations, such as PDCurses or NetBSD curses.  Here are a
           few to consider:
    
           •   The routine **has_key** is not part of XPG4, nor is it present in
               SVr4.  See the **curs_getch**(3X) manual page for details.
    
           •   The routine **slk_attr** is not part of XPG4, nor is it present in
               SVr4.  See the **curs_slk**(3X) manual page for details.
    
           •   The routines **getmouse** , **mousemask** , **ungetmouse** , **mouseinterval** ,
               and **wenclose** relating to mouse interfacing are not part of
               XPG4, nor are they present in SVr4.  See the **curs_mouse**(3X)
               manual page for details.
    
           •   The routine **mcprint** was not present in any previous curses
               implementation.  See the **curs_print**(3X) manual page for
               details.
    
           •   The routine **wresize** is not part of XPG4, nor is it present in
               SVr4.  See the **wresize**(3X) manual page for details.
    
           •   The WINDOW structure's internal details can be hidden from
               application programs.  See **curs_opaque**(3X) for the discussion
               of **is_scrollok** , etc.
    
           •   This implementation can be configured to provide rudimentary
               support for multi-threaded applications.  See **curs_threads**(3X)
               for details.
    
           •   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.
    
       **Padding differences**
           In historic curses versions, delays embedded in the capabilities
           **cr** , **ind** , **cub1** , **ff** and **tab** activated corresponding delay bits in
           the UNIX tty driver.  In this implementation, all padding is done
           by sending NUL bytes.  This method is slightly more expensive, but
           narrows the interface to the UNIX kernel significantly and
           increases the package's portability correspondingly.
    
       **Header files**
           The header file **< curses.h> **automatically includes the header files
           **< stdio.h> **and **< unctrl.h>**.
    
           X/Open Curses has more to say, but does not finish the story:
    
               The inclusion of <curses.h> may make visible all symbols from
               the headers <stdio.h>, <term.h>, <termios.h>, and <wchar.h>.
    
           Here is a more complete story:
    
           •   Starting with BSD curses, all implementations have included
               <stdio.h>.
    
               BSD curses included <curses.h> and <unctrl.h> from an internal
               header "curses.ext" ("ext" was a short name for _externs_).
    
               BSD curses used <stdio.h> internally (for **printw** and **scanw**),
               but nothing in <curses.h> itself relied upon <stdio.h>.
    
           •   SVr2 curses added **newterm**(3X), which relies upon <stdio.h>.
               That is, the function prototype uses **FILE**.
    
               SVr4 curses added **putwin** and **getwin** , which also use <stdio.h>.
    
               X/Open Curses documents all three of these functions.
    
               SVr4 curses and X/Open Curses do not require the developer to
               include <stdio.h> before including <curses.h>.  Both document
               curses showing <curses.h> as the only required header.
    
               As a result, standard <curses.h> will always include
               <stdio.h>.
    
           •   X/Open Curses is inconsistent with respect to SVr4 regarding
               <unctrl.h>.
    
               As noted in **curs_util**(3X), ncurses includes <unctrl.h> from
               <curses.h> (like SVr4).
    
           •   X/Open's comments about <term.h> and <termios.h> may refer to
               HP-UX and AIX:
    
               HP-UX curses includes <term.h> from <curses.h> to declare
               **setupterm** in curses.h, but ncurses (and Solaris curses) do
               not.
    
               AIX curses includes <term.h> and <termios.h>.  Again, ncurses
               (and Solaris curses) do not.
    
           •   X/Open says that <curses.h> _may_ include <term.h>, but there is
               no requirement that it do that.
    
               Some programs use functions declared in both <curses.h> and
               <term.h>, and must include both headers in the same module.
               Very old versions of AIX curses required including <curses.h>
               before including <term.h>.
    
               Because ncurses header files include the headers needed to
               define datatypes used in the headers, ncurses header files can
               be included in any order.  But for portability, you should
               include <curses.h> before <term.h>.
    
           •   X/Open Curses says _"may make visible"_ because including a
               header file does not necessarily make all symbols in it
               visible (there are ifdef's to consider).
    
               For instance, in ncurses <wchar.h> _may_ be included if the
               proper symbol is defined, and if ncurses is configured for
               wide-character support.  If the header is included, its
               symbols may be made visible.  That depends on the value used
               for **_XOPEN_SOURCE** feature test macro.
    
           •   X/Open Curses documents one required header, in a special
               case: <stdarg.h> before <curses.h> to prototype the **vw_printw**
               and **vw_scanw** functions (as well as the obsolete the **vwprintw**
               and **vwscanw** functions).  Each of those uses a **va_list**
               parameter.
    
               The two obsolete functions were introduced in SVr3.  The other
               functions were introduced in X/Open Curses.  In between, SVr4
               curses provided for the possibility that an application might
               include either <varargs.h> or <stdarg.h>.  Initially, that was
               done by using **void*** for the **va_list** parameter.  Later, a
               special type (defined in <stdio.h>) was introduced, to allow
               for compiler type-checking.  That special type is always
               available, because <stdio.h> is always included by <curses.h>.
    
               None of the X/Open Curses implementations require an
               application to include <stdarg.h> before <curses.h> because
               they either have allowed for a special type, or (like ncurses)
               include <stdarg.h> directly to provide a portable interface.
    


## NOTES



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


* * *