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


       #include <curses.h>

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


       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 in stdio(3).  If the advance is at the right  mar-
       gin,  the  cursor  automatically wraps to the beginning of
       the next line.  At the bottom  of  the  current  scrolling
       region,  if  scrollok  is enabled, the scrolling region is
       scrolled up one line.

       If ch is a tab, newline, or backspace, the cursor is moved
       appropriately within the window.  Backspace moves the cur-
       sor one character left; at the left edge of  a  window  it
       does  nothing.   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).  Tabs are con-
       sidered to be at every eighth column.

       If ch is any control character other than tab, newline, or
       backspace,  it  is  drawn  in  ^X notation.  Calling winch
       after adding a control character does not return the char-
       acter  itself, but instead returns the ^-representation of
       the control character.  (To emit control characters liter-
       ally, use echochar.)

       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  and
       addch.).   See the curs_attr(3X) page for values of prede-
       fined video attribute constants that can be usefully OR'ed
       into characters.

       The  echochar  and  wechochar routines are equivalent to a
       call to addch followed by a call to refresh, 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

   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  doesn't   define   a   terminal-specific
       replacement for it (but see the EXTENSIONS section below).
       The names are taken from VT100 nomenclature.

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


       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.


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


       The following extended curses features are available  only
       on  PC-clone consoles and compatible terminals obeying the
       ANSI.SYS de-facto standard for terminal control sequences.
       They are not part of XSI curses.

       The attribute A_ALTCHARSET actually forces literal display
       of PC ROM characters  including  the  high-half  graphics.
       the card-suit characters, up and down-arrow, and most oth-
       ers in the range 0-32.  (In a terminfo entry designed  for
       use  with  ncurses,  the high-half characters are obtained
       using this attribute with an acsc string in which the sec-
       ond of each pair is a high-half character.)

       Giving  wechochar  an  argument with its high bit set will
       produce the corresponding high-half  ASCII  graphic  (SVr4
       curses also has this feature but does not document it).  A
       control-character argument, however,  will  not  typically
       produce  the corresponding graphic; characters such as CR,
       NL, FF and TAB are typically interpreted  by  the  console
       driver  itself,  and ESC will be interpreted as the leader
       of a control sequence.


       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.

       The seven ACS symbols starting with ACS_S3 were not  docu-
       mented  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


       curses(3X), curs_attr(3X), curs_clear(3X),  curs_inch(3X),
       curs_outopts(3X), curs_refresh(3X), putc(3S).