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- * @Id: curs_addch.3x,v 1.81 2024/03/23 20:38:57 tom Exp @
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-<H1 class="no-header">curs_addch 3x 2024-03-23 ncurses 6.4 Library calls</H1>
+<H1 class="no-header">curs_addch 3x 2024-04-13 ncurses 6.4 Library calls</H1>
<PRE>
<STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG> Library calls <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>
line of the window.
<STRONG>o</STRONG> Line feed does a <STRONG><A HREF="curs_clear.3x.html">clrtoeol(3x)</A></STRONG>, then moves the cursor to the left
- margin on the next line of the window, scrolling the window if the
- cursor was already on the last line.
+ margin on the next line of the window, and if <STRONG><A HREF="scrollok.3x.html">scrollok(3x)</A></STRONG> is
+ enabled for <EM>win</EM>, scrolls the window if the cursor was already on
+ the last line.
- <STRONG>o</STRONG> 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 <STRONG>TABSIZE</STRONG> extension; see
+ <STRONG>o</STRONG> 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 <STRONG>TABSIZE</STRONG> extension; see
<STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>.
- If <EM>ch</EM> is any other nonprintable character, it is drawn in printable
+ If <EM>ch</EM> is any other nonprintable character, it is drawn in printable
form, using the same convention as <STRONG><A HREF="unctrl.3x.html">unctrl(3x)</A></STRONG>.
- <STRONG>o</STRONG> <STRONG>waddch</STRONG> displays control characters in <STRONG>^</STRONG><EM>X</EM> notation.
-
- <STRONG>o</STRONG> Character codes above 127 are either meta characters (if the screen
- has not been initialized, or if <STRONG><A HREF="curs_inopts.3x.html">meta(3x)</A></STRONG> has been called with a
- <STRONG>TRUE</STRONG> <EM>bf</EM> parameter) that render in <STRONG>M-</STRONG><EM>X</EM> notation, or they display as
- themselves. In the latter case, the values may not be printable;
- this follows the X/Open specification.
-
- Calling <STRONG><A HREF="curs_inch.3x.html">winch(3x)</A></STRONG> on the location of a nonprintable character does not
+ Calling <STRONG><A HREF="curs_inch.3x.html">winch(3x)</A></STRONG> on the location of a nonprintable character does not
return the character itself, but its <STRONG><A HREF="unctrl.3x.html">unctrl(3x)</A></STRONG> representation.
- Video attributes can be combined with a character argument passed to
- <STRONG>waddch</STRONG> by logical-ORing them into the character. (Thus, text,
- including attributes, can be copied from one place to another using
- <STRONG><A HREF="curs_inch.3x.html">winch(3x)</A></STRONG> and <STRONG>waddch</STRONG>.) See <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG> for values of predefined
- video attribute constants that can be usefully OR'ed with characters.
+ <EM>ch</EM> may contain rendering and/or color attributes, and others can be
+ combined with the parameter by logically "or"ing with it. (A character
+ with its attributes can be copied from place to place using <STRONG><A HREF="curs_inch.3x.html">winch(3x)</A></STRONG>
+ and <STRONG>waddch</STRONG>.) See <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG> for values of predefined video
+ attribute constants that can be usefully "or"ed with characters.
</PRE><H3><a name="h3-Echoing-Characters">Echoing Characters</a></H3><PRE>
- <STRONG>echochar</STRONG> and <STRONG>wechochar</STRONG> are equivalent to calling (<STRONG>w</STRONG>)<STRONG>addch</STRONG> followed by
- (<STRONG>w</STRONG>)<STRONG>refresh</STRONG>. <EM>curses</EM> interprets these functions as a hint that only a
+ <STRONG>echochar</STRONG> and <STRONG>wechochar</STRONG> are equivalent to calling (<STRONG>w</STRONG>)<STRONG>addch</STRONG> followed by
+ (<STRONG>w</STRONG>)<STRONG>refresh</STRONG>. <EM>curses</EM> interprets these functions as a hint that only a
single character is being output; for non-control characters, a
considerable performance gain may be enjoyed by employing them.
</PRE><H3><a name="h3-Forms-Drawing-Characters">Forms-Drawing Characters</a></H3><PRE>
- <EM>curses</EM> defines macros starting with <STRONG>ACS_</STRONG> that can be used with <STRONG>waddch</STRONG>
- to write line-drawing and other special characters to the screen.
- <EM>ncurses</EM> terms these <EM>forms-drawing</EM> <EM>characters.</EM> The ACS default listed
- below is used if the <STRONG>acs_chars</STRONG> (<STRONG>acsc</STRONG>) <EM>terminfo</EM> capability does not
- define a terminal-specific replacement for it, or if the terminal and
- locale configuration requires Unicode to access these characters but
+ <EM>curses</EM> defines macros starting with <STRONG>ACS_</STRONG> that can be used with <STRONG>waddch</STRONG>
+ to write line-drawing and other special characters to the screen.
+ <EM>ncurses</EM> terms these <EM>forms-drawing</EM> <EM>characters.</EM> The ACS default listed
+ below is used if the <STRONG>acs_chars</STRONG> (<STRONG>acsc</STRONG>) <EM>terminfo</EM> capability does not
+ define a terminal-specific replacement for it, or if the terminal and
+ locale configuration requires 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 <STRONG>acs_chars</STRONG> string
- capability, and the characters in it may appear on the screen if the
+ capability, and the characters in it may appear on the screen if the
terminal's database entry incorrectly advertises ACS support. The name
- "ACS" originates in the Alternate Character Set feature of the DEC
+ "ACS" originates in the Alternate Character Set feature of the DEC
VT100 terminal.
<STRONG>ACS</STRONG> <STRONG>acsc</STRONG>
</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
These functions return <STRONG>OK</STRONG> on success and <STRONG>ERR</STRONG> on failure.
- In <EM>ncurses</EM>, <STRONG>waddch</STRONG> returns <STRONG>ERR</STRONG> if it is not possible to add a complete
- character at the cursor position, as when conversion of a multibyte
- character to a byte sequence fails, or at least one of the resulting
- bytes cannot be added to the window. See section "PORTABILITY" below
+ In <EM>ncurses</EM>, <STRONG>waddch</STRONG> returns <STRONG>ERR</STRONG> if it is not possible to add a complete
+ character at the cursor position, as when conversion of a multibyte
+ character to a byte sequence fails, or at least one of the resulting
+ bytes cannot be added to the window. See section "PORTABILITY" below
regarding the use of <STRONG>waddch</STRONG> with multibyte characters.
- If <STRONG><A HREF="scrollok.3x.html">scrollok(3x)</A></STRONG> is not enabled, <STRONG>waddch</STRONG> can successfully write a
- character at the bottom right location of the window. However, <EM>ncurses</EM>
- returns <STRONG>ERR</STRONG> because it is not possible to wrap to a new line.
+ <STRONG>waddch</STRONG> can successfully write a character at the bottom right location
+ of the window. However, <EM>ncurses</EM> returns <STRONG>ERR</STRONG> if <STRONG><A HREF="scrollok.3x.html">scrollok(3x)</A></STRONG> is not
+ enabled in that event, because it is not possible to wrap to a new
+ line.
Functions with a "mv" prefix first perform cursor movement using
<STRONG><A HREF="curs_move.3x.html">wmove(3x)</A></STRONG> and fail if the position is outside the window, or (for "mvw"
Some ACS symbols (<STRONG>ACS_S3</STRONG>, <STRONG>ACS_S7</STRONG>, <STRONG>ACS_LEQUAL</STRONG>, <STRONG>ACS_GEQUAL</STRONG>, <STRONG>ACS_PI</STRONG>,
<STRONG>ACS_NEQUAL</STRONG>, and <STRONG>ACS_STERLING</STRONG>) were not documented in any publicly
released System V. However, many publicly available <EM>terminfo</EM> entries
- include <STRONG>acsc</STRONG> strings in which their key characters (pryz{|}) are
+ include <STRONG>acsc</STRONG> strings in which their key characters <STRONG>(</STRONG>pryz{|}<STRONG>)</STRONG> are
embedded, and a second-hand list of their character descriptions has
come to light. The <EM>ncurses</EM> developers invented ACS-prefixed names for
them.
the character code, which SVr4 packs into a <EM>chtype</EM> for passage to
<STRONG>waddch</STRONG>.
- In <EM>ncurses</EM>, <EM>chtype</EM> holds an eight-bit character. But <EM>ncurses</EM> allows a
- multibyte character to be passed in a succession of calls to <STRONG>waddch</STRONG>.
- Other implementations do not; a <STRONG>waddch</STRONG> call transmits exactly one
- character, which may be rendered in one or more screen locations
+ In <EM>ncurses</EM>, <EM>chtype</EM> holds an eight-bit character. But the library
+ allows a multibyte character to be passed in a succession of calls to
+ <STRONG>waddch</STRONG>. Other implementations do not; a <STRONG>waddch</STRONG> call transmits exactly
+ one character, which may be rendered in one or more screen locations
depending on whether it is printable.
Depending on the locale settings, <EM>ncurses</EM> inspects the byte passed in
each <STRONG>waddch</STRONG> call, and checks whether the latest call continues a
multibyte sequence. When a character is <EM>complete</EM>, <EM>ncurses</EM> displays the
- character and advances the window's current location.
+ character and advances the cursor.
If the calling application interrupts the succession of bytes in a
- multibyte character sequence by moving the current location (for
- example, with <STRONG><A HREF="curs_move.3x.html">wmove(3x)</A></STRONG>), <EM>ncurses</EM> discards the incomplete character.
+ multibyte character sequence by changing the current location--for
+ example, with <STRONG><A HREF="curs_move.3x.html">wmove(3x)</A></STRONG>--<EM>ncurses</EM> discards the incomplete character.
For portability to other implementations, do not rely upon this
behavior. Check whether a character can be represented as a single
</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
- <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_addchstr.3x.html">curs_addchstr(3x)</A></STRONG>, <STRONG><A HREF="curs_addstr.3x.html">curs_addstr(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>,
- <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>, <STRONG><A HREF="curs_inch.3x.html">curs_inch(3x)</A></STRONG>, <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>,
- <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG>putchar(3)</STRONG>
-
<STRONG><A HREF="curs_add_wch.3x.html">curs_add_wch(3x)</A></STRONG> describes comparable functions of the <EM>ncurses</EM> library
in its wide-character configuration (<EM>ncursesw</EM>).
+ <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_addchstr.3x.html">curs_addchstr(3x)</A></STRONG>, <STRONG><A HREF="curs_addstr.3x.html">curs_addstr(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>,
+ <STRONG><A HREF="curs_clear.3x.html">curs_clear(3x)</A></STRONG>, <STRONG><A HREF="curs_inch.3x.html">curs_inch(3x)</A></STRONG>, <STRONG><A HREF="curs_outopts.3x.html">curs_outopts(3x)</A></STRONG>, <STRONG><A HREF="curs_refresh.3x.html">curs_refresh(3x)</A></STRONG>,
+ <STRONG><A HREF="curs_variables.3x.html">curs_variables(3x)</A></STRONG>, <STRONG>putchar(3)</STRONG>
+
-ncurses 6.4 2024-03-23 <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>
+ncurses 6.4 2024-04-13 <STRONG><A HREF="curs_addch.3x.html">curs_addch(3x)</A></STRONG>
</PRE>
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