curs_addch 3x

curs_addch(3x)                                           curs_addch(3x)




NAME

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


SYNOPSIS

       #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);


DESCRIPTION


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 in stdio(3).  If the advance is at the right  mar-
       gin:

       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
           line

       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
           variable.

       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  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, 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
       equivalents.


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.  The names are taken from VT100 nomen-
       clature.

       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


RETURN VALUE

       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.


NOTES

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


PORTABILITY

       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
       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.


SEE ALSO

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

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



                                                         curs_addch(3x)