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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(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);
DESCRIPTION
The addch, waddch, mvaddch and mvwaddch routines put the character ch into the given win-
dow 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 win-
dow. 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 window if on the last line). Tabs are considered 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 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 predefined 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 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 rou-
tines 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 sec-
tion 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 spec-
ify only "an integer value other than ERR") upon successful completion, unless otherwise
noted in the preceding routine descriptions.
NOTES
Note that addch, mvaddch, mvwaddch, and echochar may be macros.
PORTABILITY
All these functions are described in the XSI Curses standard, Issue 4. The defaults spec-
ified 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_STER-
LING) 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).
SEE ALSO
curses(3X), curs_attr(3X), curs_clear(3X), curs_inch(3X), curs_outopts(3X),
curs_refresh(3X), putc(3S).
curs_addch(3X) |
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