curs_addch(3) UNIX Programmer's Manual curs_addch(3)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
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 margin,
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 cursor
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 win-
dow if on the last line. Tabs are considered to be at every
eighth column. The tab interval may be altered by setting
the TABSIZE variable.
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 character
itself, but instead returns the ^-representation of the con-
trol 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(3) page for values of predefined video
attribute constants that can be usefully OR'ed into charac-
ters.
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-
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curs_addch(3) UNIX Programmer's Manual curs_addch(3)
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 family.
The default character listed below is used if the acsc capa-
bility doesn't define a terminal-specific replacement for it
(but see the EXTENSIONS section below). 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
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.
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curs_addch(3) UNIX Programmer's Manual curs_addch(3)NOTES
Note that addch, mvaddch, mvwaddch, and echochar may be mac-
ros.
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.
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 avail-
able terminfos include acsc strings in which their key char-
acters (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(3).
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 ALSOcurses(3), curs_attr(3), curs_clear(3), curs_inch(3),
curs_outopts(3), curs_refresh(3), putc(3).
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