X-Git-Url: https://ncurses.scripts.mit.edu/?a=blobdiff_plain;ds=sidebyside;f=doc%2Fhtml%2Fman%2Fcurs_addch.3x.html;h=b19e72efd135d3786807d663f0f67c7265a5852e;hb=81304798ee736c467839c779c9ca5dca48db7bea;hp=c0af2f68e20bdb7db782cd268595c743b5d5b517;hpb=ed646e3f683083e787c6ba773364401dc9fa9d40;p=ncurses.git diff --git a/doc/html/man/curs_addch.3x.html b/doc/html/man/curs_addch.3x.html index c0af2f68..b19e72ef 100644 --- a/doc/html/man/curs_addch.3x.html +++ b/doc/html/man/curs_addch.3x.html @@ -1,7 +1,8 @@ -
- +#include <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); + 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);
@@ -94,34 +96,35 @@ 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 con- - trol character. + If ch is any other nonprintable character, it is drawn in printable + form, i.e., the ^X notation used by unctrl(3x). Calling winch after + adding a nonprintable character does not return the character itself, + but instead returns the printable representation of the 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(3x) and addch.) See the curs_attr(3x) page for val- - ues of predefined video attribute constants that can be usefully OR'ed - into characters. + another using inch(3x) and addch.) See the curs_attr(3x) page for + values of predefined 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(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 perfor- - mance gain may be seen by using these routines instead of their equiva- - lents. + output is used and, for non-control characters, a considerable + performance gain may be seen by using these routines instead of their + equivalents.
The following variables may be used to add line drawing characters to the screen with routines of the addch family. The default character listed below is used if the acsc capability does not define a terminal- - specific replacement for it, or if the terminal and locale configura- - tion requires Unicode but the library is unable to use Unicode. + specific replacement for it, or if the terminal and locale + configuration requires Unicode but the library is unable to use + Unicode. The names are taken from VT100 nomenclature. @@ -164,14 +167,25 @@
All routines return the integer ERR upon failure and OK on success (the - SVr4 manuals specify only "an integer value other than ERR") upon suc- - cessful completion, unless otherwise noted in the preceding routine + SVr4 manuals specify only "an integer value other than ERR") upon + successful completion, unless otherwise noted in the preceding routine descriptions. - Functions with a "mv" prefix first perform a cursor movement using + Functions with a "mv" prefix first perform a cursor movement using wmove, and return an error if the position is outside the window, or if the window pointer is null. + If it is not possible to add a complete character, an error is + returned: + + 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 + + o If an error is detected when converting a multibyte character to a + sequence of bytes, or if it is not possible to add all of the + resulting bytes in the window, an error is returned. +
Note that addch, mvaddch, mvwaddch, and echochar may be macros. @@ -182,9 +196,35 @@ 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 curs_add_wch), there are analo- - gous WACS_ definitions which are cchar_t constants. + the wide-character implementation (see curs_add_wch), there are + analogous WACS_ definitions which are cchar_t constants. Some + implementations are problematic: + + o Some implementations define the ACS symbols to a constant (such as + Solaris), while others define those to entries in an array. + + This implementation uses an array acs_map, as done in SVr4 curses. + NetBSD also uses an array, actually named _acs_char, with a #define + for compatibility. + + o HPUX curses equates some of the ACS_ symbols to the analogous WACS_ + symbols as if the ACS_ symbols were wide characters. The + misdefined symbols are the arrows and other symbols which are not + used for line-drawing. + + o 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 the various + implementations use i (lowercase). + + None of the terminal descriptions on Unix platforms use uppercase- + I, except for Solaris (i.e., screen's terminal description, + apparently based on the X/Open documentation around 1995). On the + other hand, the terminal description gs6300 (AT&T PC6300 with EMOTS + Terminal Emulator) uses lowercase-i. Some ACS symbols (ACS_S3, ACS_S7, ACS_LEQUAL, ACS_GEQUAL, ACS_PI, ACS_NEQUAL, ACS_STERLING) were not documented in any publicly released @@ -201,12 +241,48 @@ o whether the locale uses UTF-8 encoding. - In certain cases, the terminal is unable to display line-drawing char- - acters except by using UTF-8 (see the discussion of NCURSES_NO_UTF8_ACS - in ncurses(3x)). + In certain cases, the terminal is unable to display line-drawing + characters except by using UTF-8 (see the discussion 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. +
+ X/Open Curses assumes that the parameter passed to waddch contains a + single character. As discussed in curs_attr(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 chtype to pass to waddch. + + In this implementation, chtype holds an eight-bit character. But + ncurses allows multibyte characters to be passed in a succession of + calls to waddch. The other implementations do not do this; a call to + waddch passes exactly one character which may be rendered as one or + more cells on the screen depending on whether it is printable. + + Depending on the locale settings, ncurses will inspect the byte passed + in each call to waddch, and check if the latest call will continue a + multibyte sequence. When a character is complete, ncurses displays the + character and moves to the next position in the screen. + + If the calling application interrupts the succession of bytes in a + multibyte character by moving the current location (e.g., using wmove), + ncurses discards the partially built character, starting over again. + + For portability to other implementations, do not rely upon this + behavior: + + o check if a character can be represented as a single byte in the + current locale before attempting call waddch, and + + o call wadd_wch for characters which cannot be handled by waddch. + + +
+ The TABSIZE variable is implemented in SVr4 and other versions of + curses, but is not part of X/Open curses (see curs_variables(3x) for + more details). If ch 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 @@ -214,8 +290,8 @@
- curses(3x), curs_attr(3x), curs_clear(3x), curs_inch(3x), curs_out- - opts(3x), curs_refresh(3x), curs_variables(3x), putc(3). + curses(3x), curs_attr(3x), curs_clear(3x), curs_inch(3x), + curs_outopts(3x), curs_refresh(3x), curs_variables(3x), putc(3). Comparable functions in the wide-character (ncursesw) library are described in curs_add_wch(3x). @@ -237,7 +313,13 @@