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man pages section 3: Curses Library Functions

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Updated: Thursday, June 13, 2019
 
 

wechochar(3CURSES)

Name

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

Synopsis

cc [ flag ... ] file ... –lcurses [ library .. ]
#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

With the addch(), waddch(), mvaddch(), and mvwaddch() routines, the character ch is put into the window at the current cursor position of the window and the position of the window cursor is advanced. Its function is similar to that of putchar(). At the right margin, an automatic newline is performed. At the bottom of the 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. A newline also does a clrtoeol() before moving. Tabs are considered to be at every eighth column. If ch is another control character, it is drawn in the ^X notation. Calling winch() after adding a control character does not return the control character, but instead returns the representation of the control character. See curs_inch(3CURSES).

Video attributes can be combined with a character by OR-ing them into the parameter. This results in these attributes also being set. (The intent here is that text, including attributes, can be copied from one place to another using inch() and addch().) (see standout(), predefined video attribute constants, on the curs_attr(3CURSES) page).

The echochar() and wechochar() routines are functionally 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 taken into consideration and, for non-control characters, a considerable performance gain might 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. When variables are defined for the terminal, the A_ALTCHARSET bit is turned on (see curs_attr(3CURSES)). Otherwise, the default character listed below is stored in the variable. The names chosen are consistent with the VT100 nomenclature.

Name
Default
Glyph 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

Return Values

All routines return the integer ERR upon failure and an integer value other than ERR upon successful completion.

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
MT-Level
Unsafe

See Also

curs_refresh(3CURSES), curs_attr(3CURSES), curs_clear(3CURSES), curs_inch(3CURSES), curs_outopts(3CURSES), curses(3CURSES), putc(3C), attributes(7)

Notes

The header <curses.h> automatically includes the headers <stdio.h> and <unctrl.h>.

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