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. 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 char-
- acter itself, but instead returns the ^-representation of
- the control character.
+ 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
+ can be copied from one place to another using inch(3x) 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
- may be seen by using these routines instead of their
+ call to addch followed by a call to refresh(3x), 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.
- LineGraphics
+
+
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.
+ replacement for it, or if the terminal and locale configu-
+ ration requires Unicode but the library is unable to use
+ Unicode.
+
+ The names are taken from VT100 nomenclature.
NameDefaultDescription
--------------------------------------------------
@@ -151,44 +172,54 @@
ACS_VLINE | vertical line
-
All routines return the integer ERR upon failure and OK on
- success (the SVr4 manuals specify only "an integer value
+ 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
+ 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
+
+ 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
+ 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
+ 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 displayed values for the ACS_ and WACS_ constants
+ depend on
+
+ o the library configuration, i.e., ncurses versus ncurs-
+ esw, where the latter is capable of displaying Unicode
+ while the former is not, and
+
+ o whether the locale uses UTF-8 encoding.
+
+ In certain cases, the terminal is unable to display line-
+ drawing characters except by using UTF-8 (see the discus-
+ sion of NCURSES_NO_UTF8_ACS in ncurses(3x)).
+
The TABSIZE variable is implemented in some versions of
curses, but is not part of X/Open curses.
@@ -197,8 +228,7 @@
of other implementations, but is not documented.
-