svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
waddch(3x)
curs_addch(3x) Library calls curs_addch(3x)
NAME
addch, waddch, mvaddch, mvwaddch, echochar, wechochar - add a curses
character to a window and advance the cursor
SYNOPSIS
#include <ncursesw/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);
/* (integer) constants */
/* ... */ ACS_BLOCK;
/* ... */ ACS_BOARD;
/* ... */ ACS_BTEE;
/* ... */ ACS_BULLET;
/* ... */ ACS_CKBOARD;
/* ... */ ACS_DARROW;
/* ... */ ACS_DEGREE;
/* ... */ ACS_DIAMOND;
/* ... */ ACS_HLINE;
/* ... */ ACS_LANTERN;
/* ... */ ACS_LARROW;
/* ... */ ACS_LLCORNER;
/* ... */ ACS_LRCORNER;
/* ... */ ACS_LTEE;
/* ... */ ACS_PLMINUS;
/* ... */ ACS_PLUS;
/* ... */ ACS_RARROW;
/* ... */ ACS_RTEE;
/* ... */ ACS_S1;
/* ... */ ACS_S9;
/* ... */ ACS_TTEE;
/* ... */ ACS_UARROW;
/* ... */ ACS_ULCORNER;
/* ... */ ACS_URCORNER;
/* ... */ ACS_VLINE;
/* extensions */
/* ... */ ACS_GEQUAL;
/* ... */ ACS_LEQUAL;
/* ... */ ACS_NEQUAL;
/* ... */ ACS_PI;
/* ... */ ACS_S3;
/* ... */ ACS_S7;
/* ... */ ACS_STERLING;
DESCRIPTION
waddch
waddch writes the curses character ch to the window win, then advances
the cursor position, analogously to the standard C library's
putchar(3). ncurses(3X) describes the variants of this function.
Construct a curses character from a char by assignment or typecast.
Subsection “Video Attributes” of attron(3X) describes how to manipulate
its attributes and color pair. (A color pair selection is not honored
unless initialized; see start_color(3X).)
The object or expression ch may contain attributes and/or a color pair
identifier. (A chtype can be copied from place to place using
winch(3X) and waddch.) See curs_attr(3X) for values of predefined con‐
stants that can be usefully “or”ed with characters. A ch whose charac‐
ter component is a space, and whose only attribute is A_NORMAL, is a
blank character, and therefore combines with the window's background
character; see curs_bkgd(3X).
If ch is a backspace, carriage return, line feed, or tab, the cursor
moves appropriately within the window.
• Backspace moves the cursor one character left; at the left margin
of a window, it does nothing.
• Carriage return moves the cursor to the left margin on the same
line of the window.
• Line feed does a clrtoeol(3X), then advances as if from the right
margin.
• Tab advances the cursor to the next tab stop (possibly on the next
line); these are placed at every eighth column by default.
Alter the tab interval with the TABSIZE extension; see
curs_variables(3X).
If ch is any other nonprintable character, it is drawn in printable
form using the same convention as unctrl(3X). Calling winch(3X) on the
location of a nonprintable character does not return the character it‐
self, but its unctrl(3X) representation.
Adding printable characters with waddch causes it to wrap at the right
margin of the window:
• If the cursor is not at the bottom of the scrolling region and ad‐
vancement occurs at the right margin, the cursor automatically
wraps to the beginning of the next line.
• If the cursor is at the bottom of the scrolling region when ad‐
vancement occurs at the right margin, and scrollok(3X) is enabled
for win, the scrolling region scrolls up one line and the cursor
wraps as above. Otherwise, advancement and scrolling do not occur,
and waddch returns ERR.
A window's margins may coincide with the screen boundaries. This may
be a problem when ncurses updates the screen to match the curses win‐
dow. When their right and bottom margins coincide, ncurses uses dif‐
ferent strategies to handle the variations of scrolling and wrapping at
the lower-right corner by depending on the terminal capabilities:
• If the terminal does not automatically wrap as characters are added
at the right margin (i.e., auto right margins), ncurses writes the
character directly.
• If the terminal has auto right margins, but also has capabilities
for turning auto margins off and on, ncurses turns the auto margin
feature off temporarily when writing to the lower-right corner.
• If the terminal has an insertion mode which can be turned off and
on, ncurses writes the character just before the lower-right cor‐
ner, and then inserts a character to push the update into the cor‐
ner.
wechochar
echochar and wechochar are equivalent to calling (w)addch followed by
(w)refresh on stdscr or the specified window. curses interprets these
functions as a hint to its optimizer that only a single character cell
in the window is being altered between refreshes; for non-control char‐
acters, a considerable performance gain may be enjoyed by employing
them.
Forms-Drawing Characters
curses defines macros starting with ACS_ that can be used with waddch
to write line-drawing and other symbols to the screen. ncurses terms
these forms-drawing characters. curses uses the ACS default listed be‐
low if the terminal type lacks the acs_chars (acsc) capability; that
capability does not define a replacement for the character; or if the
terminal type and locale configuration require Unicode to access these
characters, but the library is unable to use Unicode. The “acsc char”
column corresponds to how the characters are specified in the acs_chars
(acsc) string capability, and the characters in it may appear on the
screen if the terminal type's database entry incorrectly advertises ACS
support. The name “ACS” originates in the Alternate Character Set fea‐
ture of the DEC VT100 terminal.
Lb Lb Lb Lb Lb Lb Lb Lb Lb L L Lx. ACS acsc Symbol De‐
fault char Glyph Name _ ACS_BLOCK # 0 solid square block
ACS_BOARD # h board of squares ACS_BTEE + v bottom tee
ACS_BULLET o ~ bullet ACS_CKBOARD : a checker board
(stipple) ACS_DARROW v . arrow pointing down ACS_DE‐
GREE ' f degree symbol ACS_DIAMOND + ` diamond
ACS_GEQUAL > > greater-than-or-equal-to
ACS_HLINE - q horizontal line ACS_LANTERN # i lantern
symbol ACS_LARROW < , arrow pointing left
ACS_LEQUAL < y less-than-or-equal-to ACS_LL‐
CORNER + m lower left-hand corner ACS_LR‐
CORNER + j lower right-hand corner ACS_LTEE + t left tee
ACS_NEQUAL ! | not-equal ACS_PI * { greek pi
ACS_PLMINUS # g plus/minus ACS_PLUS + n plus ACS_RAR‐
ROW > + arrow pointing right ACS_RTEE + u right tee
ACS_S1 - o scan line 1 ACS_S3 - p scan line 3
ACS_S7 - r scan line 7 ACS_S9 _ s scan line 9
ACS_STERLING f } pound-sterling symbol ACS_TTEE + w top
tee ACS_UARROW ^ - arrow pointing up ACS_UL‐
CORNER + l upper left-hand corner ACS_URCORNER + k up‐
per right-hand corner ACS_VLINE | x vertical line
RETURN VALUE
These functions return OK on success and ERR on failure.
In ncurses, these functions fail if
• the curses screen has not been initialized,
• (for functions taking a WINDOW pointer argument) win is a null
pointer,
• wrapping to a new line is impossible because scrollok(3X) has not
been called on win (or stdscr, as applicable) when a write to its
bottom right location is attempted, or
• it is not possible to add a complete character at the cursor posi‐
tion.
The last may be due to different causes:
• conversion of a wide character to a multibyte character sequence
can fail, or
• at least one of the bytes resulting from wide character conversion
to a multibyte character sequence cannot be added to the window.
See section “PORTABILITY” below regarding the use of waddch with
wide characters.
Functions prefixed with “mv” first perform cursor movement and fail if
the position (y, x) is outside the window boundaries.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
box; cbp-1 | cbp-1 l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE = Availabil‐
ity library/ncurses = Stability Uncommitted
NOTES
addch, mvaddch, mvwaddch, and echochar may be implemented as macros.
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at:
https://github.com/oracle/solaris-userland
The original community source was downloaded from:
https://invisible-mirror.net/archives/ncurses/cur‐
rent/ncurses-6.5-20250614.tgz
Further information about this software can be found on the open source
community website at https://invisible-island.net/ncurses/.
EXTENSIONS
The symbols ACS_S3, ACS_S7, ACS_LEQUAL, ACS_GEQUAL, ACS_PI, ACS_NEQUAL,
and ACS_STERLING were not documented in any publicly released System V
and are not standard. However, many publicly available terminfo en‐
tries include acs_chars (acsc) capabilities in which their key charac‐
ters (pryz{|}) are embedded, and a second-hand list of their character
descriptions has come to light, which identifies them as VT100 special
characters.
The DEC Special Character and Line Drawing Set (VT100) is indexed by an
ASCII character in the range 96 (`) to 126 (~). That index character
is part of the definition for the curses ACS_ symbols. The VT100 spe‐
cial characters can be categorized in three groups:
• useful graphic symbols with a standard ACS_ symbol, (e.g., the
line-drawing symbols),
• possibly useful characters (these non-standard symbols),
• representations of control characters (e.g., newline and vertical
tabulation).
A few ACS_ symbols do not fit into DEC's VT100 scheme. The AT&T Tele‐
type 5410v1 arrow symbols and ACS_BLOCK use indices outside the range
96 to 126. Two of the Teletype symbols use indices in that range, with
different meaning versus the VT100:
• ACS_BOARD corresponds to the VT100 symbol for newline
• ACS_LANTERN corresponds to the VT100 symbol for vertical tabulation
AT&T defined ACS_ names for the most useful graphic symbols, as well as
for its own. Its header file commented:
/*
* Standard alternate character set. The current ACS world is evolving,
* so we support only a widely available subset: the line drawing characters
* from the VT100, plus a few from the Teletype 5410v1. Eventually there
* may be support of more sophisticated ACS line drawing, such as that
* in the Teletype 5410, the HP line drawing set, and the like. There may
* be support for some non line oriented characters as well.
*
* Line drawing ACS names are of the form ACS_trbl, where t is the top, r
* is the right, b is the bottom, and l is the left. t, r, b, and l might
* be B (blank), S (single), D (double), or T (thick). The subset defined
* here only uses B and S.
*/
Although these less-useful graphic symbols were not given names, they
were used in terminfo entries. The ncurses developers invented ACS-
prefixed names for them.
PORTABILITY
Applications employing ncurses extensions should condition their use on
the visibility of the NCURSES_VERSION preprocessor macro.
X/Open Curses Issue 4 describes these functions. It specifies no error
conditions for them.
SVr4 describes a successful return value only as “an integer value
other than ERR”.
The defaults specified for forms-drawing characters apply in the POSIX
locale.
ACS Symbols
X/Open Curses states that the ACS_ definitions are char constants.
Some implementations are problematic.
• Solaris curses, for example, defines the ACS symbols as constants;
others define them as elements of an array.
SVr4 used an array, acs_map, as does ncurses. NetBSD curses also
uses an array, actually named _acs_char, with a “#define” for com‐
patibility.
• HP-UX curses equates some of the ACS_ symbols to the analogous
WACS_ symbols as if the ACS_ symbols were wide characters (see
curs_add_wch(3X)). The misdefined symbols are the arrows and oth‐
ers that are not used for line drawing.
• X/Open Curses (Issues 2 through 7) has a typographical error for
the ACS_LANTERN symbol, equating its “VT100+ Character” to “I”
(capital I), while the header files for SVr4 curses and other im‐
plementations use “i” (small i).
None of the terminal descriptions on Unix platforms use uppercase
I, except for Solaris (in its terminfo entry for screen(1), appar‐
ently based on the X/Open documentation around 1995). On the other
hand, its gs6300 (AT&T PC6300 with EMOTS Terminal Emulator) de‐
scription uses lowercase i.
The displayed values of ACS_ constants depend on
• the ncurses ABI — for example, wide-character versus non-wide-char‐
acter configurations (the former is capable of displaying Unicode
while the latter is not), and
• whether the locale uses UTF-8 encoding.
In certain cases, the terminal is unable to display forms-drawing char‐
acters except by using UTF-8; see the discussion of the
NCURSES_NO_UTF8_ACS environment variable in ncurses(3X).
Character Set
X/Open Curses assumes that the parameter passed to waddch contains a
single character. That character may have been more than eight bits
wide in an SVr3 or SVr4 implementation, but X/Open Curses leaves the
width of a non-wide character code unspecified. The standard further
does not specify the internal structure of a chtype, though the use of
bit operations to combine the character code with attributes and a
color pair identifier into a chtype for passage to waddch is common. A
portable application uses only the macros discussed in curs_attr(3X) to
manipulate a chtype.
In ncurses, chtype holds an eight-bit character, but the library allows
a multibyte character sequence to be passed via a succession of calls
to waddch. Other implementations do not; a waddch call transmits ex‐
actly one character, which may be rendered in one or more screen loca‐
tions depending on whether it is printable (see unctrl(3X)). Depending
on the locale, ncurses inspects the byte passed in each waddch call and
checks whether the latest call continues a multibyte character. When a
character is complete, ncurses displays the character and advances the
cursor. If the calling application interrupts the succession of bytes
in a multibyte character sequence by changing the current location —
for example, with wmove(3X) — ncurses discards the incomplete charac‐
ter.
For portability to other implementations, do not rely upon the forego‐
ing behavior. Check whether a character can be represented as a single
byte in the current locale.
• If it can, call either waddch or wadd_wch.
• If it cannot, use only wadd_wch.
HISTORY
4BSD (1980) introduced waddch and its variants.
SVr3 (1987) added the echochar and wechochar functions and most of the
ACS_ constants, except for ACS_GEQUAL, ACS_LEQUAL, ACS_NEQUAL, ACS_PI,
ACS_S3, ACS_S7, and ACS_STERLING.
ncurses 1.9.6 (1995) furnished the remaining ACS_ constants.
SEE ALSO
curs_add_wch(3X) describes comparable functions of the ncurses library
in its wide-character configuration (ncursesw).
curses(3X), curs_addchstr(3X), curs_addstr(3X), curs_attr(3X),
curs_bkgd(3X), curs_clear(3X), curs_inch(3X), curs_outopts(3X),
curs_refresh(3X), curs_variables(3X), putchar(3)
ncurses 6.5 2025-04-26 curs_addch(3x)