'\" t
.TH curs_addch 3X ""
.SH NAME
\fBaddch\fR, \fBwaddch\fR, \fBmvaddch\fR, \fBmvwaddch\fR,
\fBechochar\fR, \fBwechochar\fR - add a character (with attributes) to a
\fBcurses\fR window, then advance the cursor
.SH SYNOPSIS
\fB#include <curses.h>\fR
\fBint addch(chtype ch);\fR
.br
\fBint waddch(WINDOW *win, chtype ch);\fR
.br
\fBint mvaddch(int y, int x, chtype ch);\fR
.br
\fBint mvwaddch(WINDOW *win, int y, int x, chtype ch);\fR
.br
\fBint echochar(chtype ch);\fR
.br
\fBint wechochar(WINDOW *win, chtype ch);\fR
.br
.SH DESCRIPTION
The \fBaddch\fR, \fBwaddch\fR, \fBmvaddch\fR and \fBmvwaddch\fR routines put
the character \fIch\fR into the given window at its current window position,
which is then advanced. They are analogous to \fBputchar\fR in \fBstdio\fR(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
\fBscrollok\fR is enabled, the scrolling region is scrolled up one line.
If \fIch\fR 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 \fBclrtoeol\fR, 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 \fIch\fR is any control character other than tab, newline, or backspace, it
is drawn in \fB^\fR\fIX\fR notation. Calling \fBwinch\fR after adding a
control character does not return the character itself, but instead returns
the ^-representation of the control character. (To emit control characters
literally, use \fBechochar\fR.)
Video attributes can be combined with a character argument passed to
\fBaddch\fR or related functions by logical-ORing them into the character.
(Thus, text, including attributes, can be copied from one place to another
using \fBinch\fR and \fBaddch\fR.). See the \fBcurs_attr\fR(3X) page for
values of predefined video attribute constants that can be usefully ORed
into characters.
The \fBechochar\fR and \fBwechochar\fR routines are equivalent to a call to
\fBaddch\fR followed by a call to \fBrefresh\fR, or a call to \fBwaddch\fR
followed by a call to \fBwrefresh\fR. 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.
.SS Line Graphics
The following variables may be used to add line drawing characters to the
screen with routines of the \fBaddch\fR family. The default character listed
below is used if the \fBacsc\fR capability doesn't define a terminal-specific
replacement for it (but see the EXTENSIONS section below). The names are
taken from VT100 nomenclature.
.TS
l l l
_ _ _
l l l.
\fIName\fR \fIDefault\fR \fIDescription\fR
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
ACS_S3 - scan line 3
ACS_S7 - scan line 7
ACS_LEQUAL < less-than-or-equal-to
ACS_GEQUAL > greater-than-or-equal-to
ACS_PI * greek pi
ACS_NEQUAL ! not-equal
ACS_STERLING f pound-sterling symbol
.TE
.SH RETURN VALUE
All routines return the integer \fBERR\fR upon failure and \fBOK\fR on success
(the SVr4 manuals specify only "an integer value other than \fBERR\fR") upon
successful completion, unless otherwise noted in the preceding routine
descriptions.
.SH NOTES
Note that \fBaddch\fR, \fBmvaddch\fR, \fBmvwaddch\fR, and
\fBechochar\fR may be macros.
.SH EXTENSIONS
The following extended \fBcurses\fR features are available only on PC-clone
consoles and compatible terminals obeying the ANSI.SYS de-facto standard for
terminal control sequences. They are not part of XSI curses.
The attribute A_ALTCHARSET actually forces literal display of PC ROM characters
including the high-half graphics. Your console driver may still capture or
translate a few (such as ESC) but this feature should give you access to the
card-suit characters, up and down-arrow, and most others in the range 0-32.
(In a terminfo entry designed for use with \fBncurses\fR, the high-half
characters are obtained using this attribute with an \fBacsc\fR string in
which the second of each pair is a high-half character.)
Giving \fBwechochar\fR an argument with its high bit set will produce the
corresponding high-half ASCII graphic (SVr4 curses also has this feature but
does not document it). A control-character argument, however, will not
typically produce the corresponding graphic; characters such as CR, NL, FF and
TAB are typically interpreted by the console driver itself, and ESC will be
interpreted as the leader of a control sequence.
.SH PORTABILITY
All these functions are described in the XSI Curses standard, Issue 4.
The defaults specified for forms-drawing characters apply in the POSIX locale.
The seven ACS symbols starting with \fBACS_S3\fR were not documented in
any publicly released System V. However, many publicly available terminfos
include \fBacsc\fR 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 \fBncurses\fR(3X).
.SH SEE ALSO
\fBcurses\fR(3X), \fBcurs_attr\fR(3X), \fBcurs_clear\fR(3X),
\fBcurs_inch\fR(3X), \fBcurs_outopts\fR(3X), \fBcurs_refresh\fR(3X),
\fBputc\fR(3S).
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