ncurses(3x) — Linux manual page


ncurses(3X)                                                  ncurses(3X)

NAME         top

       ncurses - CRT screen handling and optimization package

SYNOPSIS         top

       #include <curses.h>

DESCRIPTION         top

       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

       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.

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

           setlocale(LC_ALL, "");

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

       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.]

       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

       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


       (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


       and if that fails, it then checks


       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,

       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:

               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

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

               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:

                    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

                    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.

                    stores a “wide” character.  Like chtype, this may be
                    an integer.

                    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         top

       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         top

       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.

       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.

       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

       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.

       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

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


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

       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.

       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

       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.

       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 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 settings to avoid the problem.

       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.

       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.

       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.

       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.

       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

       See curs_trace(3X) for more information.

       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

       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.

       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.

       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.,


           rather than


           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

          •   $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

             •   @TERMINFO@ (corresponding to the TERMINFO variable)

       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

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

       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.


       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:

            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.

            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


            you link with


            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 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.

            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.




            The shared and normal (static) library names differ by their
            suffixes, e.g., 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.

            Low-level functions which do not depend upon whether the
            library supports wide-characters, are provided in the tinfo

            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

            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

            •   curs_util(3X) - miscellaneous curses utility routines

            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

FILES         top

            directory containing initialization files for the terminal
            capability database @TERMINFO@ terminal capability database

SEE ALSO         top

       terminfo(5) and related pages whose names begin “curs_” for
       detailed routine descriptions.
       user_caps(5) for user-defined capabilities

EXTENSIONS         top

       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

       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

       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         top

       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

       •   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

           BSD curses included <curses.h> and <unctrl.h> from an
           internal header "curses.ext" ("ext" was a short name for

           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

           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

       •   X/Open Curses is inconsistent with respect to SVr4 regarding

           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

           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

           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

NOTES         top

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

AUTHORS         top

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

COLOPHON         top

       This page is part of the ncurses (new curses) project.
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