curs_addch(3x) Library calls curs_addch(3x)
@@ -89,54 +89,47 @@
line of the window.
o Line feed does a clrtoeol(3x), 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 scrollok(3x) is
+ enabled for win, scrolls the window if the cursor was already on
+ the last line.
- o 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 TABSIZE extension; see
+ o 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 TABSIZE extension; see
curs_variables(3x).
- If ch is any other nonprintable character, it is drawn in printable
+ If ch is any other nonprintable character, it is drawn in printable
form, using the same convention as unctrl(3x).
- owaddch displays control characters in ^X notation.
-
- o Character codes above 127 are either meta characters (if the screen
- has not been initialized, or if meta(3x) has been called with a
- TRUEbf parameter) that render in M-X notation, or they display as
- themselves. In the latter case, the values may not be printable;
- this follows the X/Open specification.
-
- Calling winch(3x) on the location of a nonprintable character does not
+ Calling winch(3x) on the location of a nonprintable character does not
return the character itself, but its unctrl(3x) representation.
- Video attributes can be combined with a character argument passed to
- waddch by logical-ORing them into the character. (Thus, text,
- including attributes, can be copied from one place to another using
- winch(3x) and waddch.) See curs_attr(3x) for values of predefined
- video attribute constants that can be usefully OR'ed with characters.
+ ch 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 winch(3x)
+ and waddch.) See curs_attr(3x) for values of predefined video
+ attribute constants that can be usefully "or"ed with characters.
- echochar and wechochar are equivalent to calling (w)addch followed by
- (w)refresh. curses interprets these functions as a hint that only a
+ echochar and wechochar are equivalent to calling (w)addch followed by
+ (w)refresh. curses 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.
- curses defines macros starting with ACS_ that can be used with waddch
- to write line-drawing and other special characters to the screen.
- ncurses terms these forms-drawingcharacters. The ACS default listed
- below is used if the acs_chars (acsc) terminfo capability does not
- define a terminal-specific replacement for it, or if the terminal and
- locale configuration requires Unicode to access these characters but
+ curses defines macros starting with ACS_ that can be used with waddch
+ to write line-drawing and other special characters to the screen.
+ ncurses terms these forms-drawingcharacters. The ACS default listed
+ below is used if the acs_chars (acsc) terminfo 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 acs_chars 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.
ACSacsc
@@ -179,15 +172,16 @@
These functions return OK on success and ERR on failure.
- In ncurses, waddch returns ERR 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 ncurses, waddch returns ERR 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 waddch with multibyte characters.
- If scrollok(3x) is not enabled, waddch can successfully write a
- character at the bottom right location of the window. However, ncurses
- returns ERR because it is not possible to wrap to a new line.
+ waddch can successfully write a character at the bottom right location
+ of the window. However, ncurses returns ERR if scrollok(3x) 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
wmove(3x) and fail if the position is outside the window, or (for "mvw"
@@ -235,7 +229,7 @@
Some ACS symbols (ACS_S3, ACS_S7, ACS_LEQUAL, ACS_GEQUAL, ACS_PI,
ACS_NEQUAL, and ACS_STERLING) were not documented in any publicly
released System V. However, many publicly available terminfo entries
- include acsc strings in which their key characters (pryz{|}) are
+ include acsc strings in which their key characters (pryz{|}) are
embedded, and a second-hand list of their character descriptions has
come to light. The ncurses developers invented ACS-prefixed names for
them.
@@ -263,20 +257,20 @@
the character code, which SVr4 packs into a chtype for passage to
waddch.
- In ncurses, chtype holds an eight-bit character. But ncurses allows a
- multibyte character to be passed in a succession of calls to waddch.
- Other implementations do not; a waddch call transmits exactly one
- character, which may be rendered in one or more screen locations
+ In ncurses, chtype holds an eight-bit character. But the library
+ allows a multibyte character to be passed in a succession of calls to
+ waddch. Other implementations do not; a waddch 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, ncurses inspects the byte passed in
each waddch call, and checks whether the latest call continues a
multibyte sequence. When a character is complete, ncurses 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 wmove(3x)), ncurses discards the incomplete character.
+ multibyte character sequence by changing the current location--for
+ example, with wmove(3x)--ncurses 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
@@ -293,16 +287,16 @@