'\" t .\"*************************************************************************** .\" Copyright (c) 1998-2015,2017 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 1.44 2017/11/20 01:27:20 tom Exp $ .TH addch 3NCURSES "" .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 \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 \fR .PP \fBint addch(const chtype ch);\fR .br \fBint waddch(WINDOW *win, const chtype ch);\fR .br \fBint mvaddch(int y, int x, const chtype ch);\fR .br \fBint mvwaddch(WINDOW *win, int y, int x, const chtype ch);\fR .br \fBint echochar(const chtype ch);\fR .br \fBint wechochar(WINDOW *win, const chtype ch);\fR .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, 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 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 using \fBinch\fR(3X) and \fBaddch\fR.) See the \fBattr\fR(3NCURSES) page for 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 \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 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 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 .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. .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 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. .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 to light. The ACS-prefixed names for them were invented for \fBncurses\fR(3NCURSES). .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 \fBncurses\fR(3NCURSES), \fBattr\fR(3NCURSES), \fBclear\fR(3NCURSES), \fBinch\fR(3NCURSES), \fBoutopts\fR(3NCURSES), \fBrefresh\fR(3NCURSES), \fBcurses_variables\fR(3NCURSES), \fBputc\fR(3). .PP Comparable functions in the wide-character (ncursesw) library are described in \fBadd_wch\fR(3NCURSES).