curs_addch 3x

curs_addch(3x)                                           curs_addch(3x)


       addch,  waddch,  mvaddch,  mvwaddch, echochar, wechochar -
       add a character (with attributes) to a curses window, then
       advance the cursor


       #include <curses.h>

       int addch(const chtype ch);
       int waddch(WINDOW *win, const chtype ch);
       int mvaddch(int y, int x, const chtype ch);
       int mvwaddch(WINDOW *win, int y, int x, const chtype ch);
       int echochar(const chtype ch);
       int wechochar(WINDOW *win, const chtype ch);


Adding characters

       The  addch,  waddch, mvaddch and mvwaddch routines put the
       character ch into the given window at its  current  window
       position,  which  is then advanced.  They are analogous to
       putchar(3) in stdio(3).  If the advance is  at  the  right

       o   The cursor automatically wraps to the beginning of the
           next line.

       o   At the bottom of the current scrolling region, and  if
           scrollok  is enabled, the scrolling region is scrolled
           up one line.

       o   If scrollok is not enabled, writing a character at the
           lower  right  margin  succeeds.   However, an error is
           returned because it is not possible to wrap to  a  new

       If ch is a tab, newline, carriage return or backspace, the
       cursor is moved appropriately within the window:

       o   Backspace moves the cursor one character left; at  the
           left edge of a window it does nothing.

       o   Carriage  return  moves  the cursor to the window left
           margin on the current line.

       o   Newline does a clrtoeol, then moves the cursor to  the
           window  left  margin  on  the next line, scrolling the
           window if on the last line.

       o   Tabs are considered to be at every eighth column.  The
           tab  interval  may  be  altered by setting the TABSIZE

       If ch is any other control character, it is  drawn  in  ^X
       notation.   Calling winch after adding a control character
       does not return the character itself, but instead  returns
       the ^-representation of the control character.

       Video attributes can be combined with a character argument
       passed to addch or related functions by logical-ORing them
       into  the  character.   (Thus, text, including attributes,
       can be copied from one place to another using inch(3x) and
       addch.)   See  the curs_attr(3x) page for values of prede-
       fined video attribute constants that can be usefully OR'ed
       into characters.

Echoing characters

       The  echochar  and  wechochar routines are equivalent to a
       call to addch followed by a call to refresh(3x), or a call
       to  waddch  followed by a call to wrefresh.  The knowledge
       that only a single character is being output is used  and,
       for  non-control  characters,  a  considerable performance
       gain may be seen by using these routines instead of  their

Line Graphics

       The  following  variables  may be used to add line drawing
       characters to the screen with routines of the  addch  fam-
       ily.   The  default  character listed below is used if the
       acsc  capability  does  not  define  a   terminal-specific
       replacement for it, or if the terminal and locale configu-
       ration requires Unicode but the library is unable  to  use

       The names are taken from VT100 nomenclature.

       Name           Default   Description
       ACS_BLOCK      #         solid square block
       ACS_BOARD      #         board of squares
       ACS_BTEE       +         bottom tee
       ACS_BULLET     o         bullet
       ACS_CKBOARD    :         checker board (stipple)
       ACS_DARROW     v         arrow pointing down
       ACS_DEGREE     '         degree symbol
       ACS_DIAMOND    +         diamond
       ACS_GEQUAL     >         greater-than-or-equal-to
       ACS_HLINE      -         horizontal line
       ACS_LANTERN    #         lantern symbol
       ACS_LARROW     <         arrow pointing left
       ACS_LEQUAL     <         less-than-or-equal-to
       ACS_LLCORNER   +         lower left-hand corner
       ACS_LRCORNER   +         lower right-hand corner
       ACS_LTEE       +         left tee
       ACS_NEQUAL     !         not-equal
       ACS_PI         *         greek pi
       ACS_PLMINUS    #         plus/minus
       ACS_PLUS       +         plus
       ACS_RARROW     >         arrow pointing right
       ACS_RTEE       +         right tee
       ACS_S1         -         scan line 1
       ACS_S3         -         scan line 3
       ACS_S7         -         scan line 7
       ACS_S9         _         scan line 9
       ACS_STERLING   f         pound-sterling symbol
       ACS_TTEE       +         top tee
       ACS_UARROW     ^         arrow pointing up
       ACS_ULCORNER   +         upper left-hand corner
       ACS_URCORNER   +         upper right-hand corner
       ACS_VLINE      |         vertical line


       All routines return the integer ERR upon failure and OK on
       success (the SVr4 manuals specify only "an  integer  value
       other than ERR") upon successful completion, unless other-
       wise noted in the preceding routine descriptions.

       Functions with a "mv" prefix first perform a cursor  move-
       ment  using  wmove, and return an error if the position is
       outside the window, or if the window pointer is null.


       Note that addch, mvaddch, mvwaddch, and  echochar  may  be


       All  these functions are described in the XSI Curses stan-
       dard, Issue 4.  The defaults specified  for  forms-drawing
       characters apply in the POSIX locale.

       X/Open  Curses  states  that the ACS_ definitions are char
       constants.  For  the  wide-character  implementation  (see
       curs_add_wch), there are analogous WACS_ definitions which
       are cchar_t constants.

       Some ACS symbols (ACS_S3, ACS_S7, ACS_LEQUAL,  ACS_GEQUAL,
       ACS_PI,  ACS_NEQUAL,  ACS_STERLING) were not documented in
       any publicly released System V.   However,  many  publicly
       available  terminfos  include  acsc strings in which their
       key characters (pryz{|}) are embedded, and  a  second-hand
       list  of  their  character descriptions has come to light.
       The  ACS-prefixed  names  for  them  were   invented   for

       The  displayed  values  for  the  ACS_ and WACS_ constants
       depend on

       o   the library configuration, i.e., ncurses versus ncurs-
           esw, where the latter is capable of displaying Unicode
           while the former is not, and

       o   whether the locale uses UTF-8 encoding.

       In certain cases, the terminal is unable to display  line-
       drawing  characters except by using UTF-8 (see the discus-
       sion of NCURSES_NO_UTF8_ACS in ncurses(3x)).

       The TABSIZE variable is implemented in  some  versions  of
       curses, but is not part of X/Open curses.

       If  ch  is  a  carriage return, the cursor is moved to the
       beginning of the current row of the window.  This is  true
       of other implementations, but is not documented.


       curses(3x),  curs_attr(3x), curs_clear(3x), curs_inch(3x),
       curs_outopts(3x),  curs_refresh(3x),   curs_variables(3x),

       Comparable  functions  in  the  wide-character  (ncursesw)
       library are described in curs_add_wch(3x).