ncurses 6.1 - patch 20181208

[ncurses.git] / man / curs_addch.3x

diff --git a/man/curs_addch.3x b/man/curs_addch.3x
index d00bd1b49a3604e79126e5933c4de354fb6e8ea4..d502faabdb03521d40697f15450adbf7f45c77ac 100644 (file)
--- a/man/curs_addch.3x
+++ b/man/curs_addch.3x
@@ -1,146 +1,273 @@
 '\" t
 '\" t

+.\"***************************************************************************
+.\" Copyright (c) 1998-2017,2018 Free Software Foundation, Inc.              *
+.\"                                                                          *
+.\" Permission is hereby granted, free of charge, to any person obtaining a  *
+.\" copy of this software and associated documentation files (the            *
+.\" "Software"), to deal in the Software without restriction, including      *
+.\" without limitation the rights to use, copy, modify, merge, publish,      *
+.\" distribute, distribute with modifications, sublicense, and/or sell       *
+.\" copies of the Software, and to permit persons to whom the Software is    *
+.\" furnished to do so, subject to the following conditions:                 *
+.\"                                                                          *
+.\" The above copyright notice and this permission notice shall be included  *
+.\" in all copies or substantial portions of the Software.                   *
+.\"                                                                          *
+.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
+.\" OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
+.\" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
+.\" IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
+.\" DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
+.\" OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
+.\" THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
+.\"                                                                          *
+.\" Except as contained in this notice, the name(s) of the above copyright   *
+.\" holders shall not be used in advertising or otherwise to promote the     *
+.\" sale, use or other dealings in this Software without prior written       *
+.\" authorization.                                                           *
+.\"***************************************************************************
+.\"
+.\" $Id: curs_addch.3x,v 1.46 2018/07/28 21:02:35 tom Exp $

 .TH curs_addch 3X ""
 .TH curs_addch 3X ""

+.ie \n(.g .ds `` \(lq
+.el       .ds `` ``
+.ie \n(.g .ds '' \(rq
+.el       .ds '' ''
+.de bP
+.ie n  .IP \(bu 4
+.el    .IP \(bu 2
+..

 .SH NAME
 .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
+\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
 .SH SYNOPSIS
 \fB#include <curses.h>\fR

-
-\fBint addch(chtype ch);\fR
+.PP
+\fBint addch(const chtype ch);\fR

 .br
 .br

-\fBint waddch(WINDOW *win, chtype ch);\fR
+\fBint waddch(WINDOW *win, const chtype ch);\fR

 .br
 .br

-\fBint mvaddch(int y, int x, chtype ch);\fR
+\fBint mvaddch(int y, int x, const chtype ch);\fR

 .br
 .br

-\fBint mvwaddch(WINDOW *win, int y, int x, chtype ch);\fR
+\fBint mvwaddch(WINDOW *win, int y, int x, const chtype ch);\fR

 .br
 .br

-\fBint echochar(chtype ch);\fR
+\fBint echochar(const chtype ch);\fR

 .br
 .br

-\fBint wechochar(WINDOW *win, chtype ch);\fR
+\fBint wechochar(WINDOW *win, const chtype ch);\fR

 .br
 .SH DESCRIPTION
 .br
 .SH DESCRIPTION

+.SS Adding characters

 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,
 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
+which is then advanced.
+They are analogous to \fBputchar\fR(3) in \fBstdio\fR(3).
+If the advance is at the right margin:
+.bP
+The cursor automatically wraps to the beginning of the next line.
+.bP
+At the bottom of the current scrolling region,
+and if \fBscrollok\fR is enabled,
+the scrolling region is scrolled up one line.
+.bP
+If \fBscrollok\fR 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
+.PP
+If \fIch\fR is a tab, newline, carriage return or backspace,
+the cursor is moved appropriately within the window:
+.bP
+Backspace moves the cursor one character left; at the left
+edge of a window it does nothing.
+.bP
+Carriage return moves the cursor to the window left margin on the current line.
+.bP
+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.
+.bP
+Tabs are considered to be at every eighth column.
+The tab interval may be altered by setting the \fBTABSIZE\fR variable.
+.PP
+If \fIch\fR is any other control character, 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
 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.)
-
+the ^-representation of the control character.
+.PP

 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
 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
+using \fBinch\fR(3X) and \fBaddch\fR.)  See the \fBcurs_attr\fR(3X) page for

 values of predefined video attribute constants that can be usefully OR'ed
 into characters.
 values of predefined video attribute constants that can be usefully OR'ed
 into characters.

-
+.SS Echoing characters
+.PP

 The \fBechochar\fR and \fBwechochar\fR routines are equivalent to a call to
 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
+\fBaddch\fR followed by a call to \fBrefresh\fR(3X), 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
 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.
-
+screen with routines of the \fBaddch\fR family.
+The default character listed
+below is used if the \fBacsc\fR capability does not define a terminal-specific
+replacement for it,
+or if the terminal and locale configuration requires Unicode but the
+library is unable to use Unicode.
+.PP
+The names are taken from VT100 nomenclature.
+.PP

 .TS
 .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
+l l l l
+l l l l
+_ _ _ _
+l l l l.
+\fBACS\fR      \fBACS\fR       \fBacsc\fP      \fBGlyph\fR
+\fBName\fR     \fBDefault\fR   \fBchar\fP      \fBName\fR
+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_DEGREE     '       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_LLCORNER   +       m       lower left-hand corner
+ACS_LRCORNER   +       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_RARROW     >       +       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_ULCORNER   +       l       upper left-hand corner
+ACS_URCORNER   +       k       upper right-hand corner
+ACS_VLINE      |       x       vertical line

 .TE
 .TE

-

 .SH RETURN VALUE
 All routines return the integer \fBERR\fR upon failure and \fBOK\fR on success
 .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.
+(the SVr4 manuals specify only
+\*(``an integer value other than \fBERR\fR\*('') upon successful completion,
+unless otherwise noted in the preceding routine descriptions.
+.PP
+Functions with a \*(``mv\*('' prefix first perform a cursor movement using
+\fBwmove\fP, and return an error if the position is outside the window,
+or if the window pointer is null.

 .SH NOTES
 Note that \fBaddch\fR, \fBmvaddch\fR, \fBmvwaddch\fR, and
 \fBechochar\fR may be macros.
 .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.
 .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 
+.SS ACS Symbols
+.LP
+X/Open Curses states that the \fIACS_\fP definitions are \fBchar\fP constants.
+For the wide-character implementation (see \fBcurs_add_wch\fP),
+there are analogous \fIWACS_\fP definitions which are \fBcchar_t\fP constants.
+.LP
+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 \fBacsc\fR strings in which their key characters (pryz{|}) are

 embedded, and a second-hand list of their character descriptions has come
 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).
+to light.
+The ACS-prefixed names for them were invented for \fBncurses\fR(3X).
+.LP
+The \fIdisplayed\fP values for the \fIACS_\fP and \fIWACS_\fP constants
+depend on 
+.bP
+the library configuration, i.e., \fBncurses\fP versus \fBncursesw\fP,
+where the latter is capable of displaying Unicode while the former is not, and
+.bP
+whether the \fIlocale\fP uses UTF-8 encoding.
+.LP
+In certain cases, the terminal is unable to display line-drawing characters
+except by using UTF-8 (see the discussion of \fBNCURSES_NO_UTF8_ACS\fP in
+ncurses(3X)).
+.SS Character Set
+X/Open Curses assumes that the parameter passed to \fBwaddch\fP contains
+a single character.
+As discussed in \fBcurs_attr\fP(3X), that character may have been
+more than eight bits in an SVr3 or SVr4 implementation,
+but in the X/Open Curses model, the details are not given.
+The important distinction between SVr4 curses and X/Open Curses is
+that the non-character information (attributes and color) was
+separated from the character information which is packed in a \fBchtype\fP
+to pass to \fBwaddch\fP.
+.PP
+In this implementation, \fBchtype\fP holds eight bits.
+But ncurses allows multibyte characters to be passed in a succession
+of calls to \fBwaddch\fP.
+The other implementations do not do this;
+a call to \fBwaddch\fP passes exactly one character
+which may be rendered as one or more cells on the screen
+depending on whether it is printable.
+.PP
+Depending on the locale settings,
+ncurses will inspect the byte passed in each call to \fBwaddch\fP,
+and check if the latest call will continue a multibyte sequence.
+When a character is \fIcomplete\fP,
+ncurses displays the character and moves to the next position in the screen.
+.PP
+If the calling application interrupts the succession of bytes in
+a multibyte character by moving the current location (e.g., using \fBwmove\fP),
+ncurses discards the partially built character,
+starting over again.
+.PP
+For portability to other implementations,
+do not rely upon this behavior:
+.bP
+check if a character can be represented as a single byte in the current locale
+before attempting call \fBwaddch\fP, and
+.bP
+call \fBwadd_wch\fP for characters which cannot be handled by \fBwaddch\fP.
+.SS TABSIZE
+.LP
+The \fBTABSIZE\fR variable is implemented in some versions of curses,
+but is not part of X/Open curses.
+.LP
+If \fIch\fR is a carriage return,
+the cursor is moved to the beginning of the current row of the window.
+This is true of other implementations, but is not documented.

 .SH SEE ALSO
 .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).
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+\fBcurses\fR(3X),
+\fBcurs_attr\fR(3X),
+\fBcurs_clear\fR(3X),
+\fBcurs_inch\fR(3X),
+\fBcurs_outopts\fR(3X),
+\fBcurs_refresh\fR(3X),
+\fBcurs_variables\fR(3X),
+\fBputc\fR(3).
+.PP
+Comparable functions in the wide-character (ncursesw) library are
+described in
+\fBcurs_add_wch\fR(3X).