These routines manipulate the current attributes of the
named window. The current attributes of a window apply to
- all characters that are written into the window with wad-
- dch, waddstr and wprintw. Attributes are a property of
- the character, and move with the character through any
+ all characters that are written into the window with wadd-
+ ch, waddstr and wprintw. Attributes are a property of the
+ character, and move with the character through any
scrolling and insert/delete line/character operations. To
the extent possible, they are displayed as appropriate
modifications to the graphic rendition of characters put
on the screen.
+
+
The routine attrset sets the current attributes of the
given window to attrs. The routine attroff turns off the
named attributes without turning any other attributes on
@@ -113,23 +117,45 @@
same as attrset(A_NORMAL) or attrset(0), that is, it turns
off all attributes.
- The attrset and related routines do not affect the
- attributes used when erasing portions of the window. See
+ The attrset and related routines do not affect the at-
+ tributes used when erasing portions of the window. See
curs_bkgd(3x) for functions which modify the attributes
used for erasing and clearing.
- The routine color_set sets the current color of the given
- window to the foreground/background combination described
- by the color_pair_number. The parameter opts is reserved
+
+
+ The attrset routine is actually a legacy feature predating
+ SVr4 curses but kept in X/Open Curses for the same reason
+ that SVr4 curses kept it: compatibility. The routine at-
+ tr_set provides for passing a color-pair parameter.
+
+ The remaining attr_* functions operate exactly like the
+ corresponding attr* functions, except that they take argu-
+ ments of type attr_t rather than int.
+
+
+
+ The routine color_set sets the current color of the given
+ window to the foreground/background combination described
+ by the color_pair_number. The parameter opts is reserved
for future use, applications must supply a null pointer.
- The routine wattr_get returns the current attribute and
+
+
+ The routine wattr_get returns the current attribute and
color pair for the given window; attr_get returns the cur-
- rent attribute and color pair for stdscr. The remaining
- attr_* functions operate exactly like the corresponding
- attr* functions, except that they take arguments of type
- attr_t rather than int.
+ rent attribute and color pair for stdscr.
+
+ There is no corresponding attrget function as such in
+ X/Open Curses, although ncurses provides getattrs (see
+ curs_legacy(3x)).
+
+
The routine chgat changes the attributes of a given number
of characters starting at the current cursor location of
stdscr. It does not update the cursor and does not per-
@@ -138,103 +164,177 @@
the way to the end of the current line. The wchgat func-
tion generalizes this to any window; the mvwchgat function
does a cursor move before acting. In these functions, the
- color argument is a color-pair index (as in the first
- argument of init_pair, see curs_color(3x)). The opts
- argument is not presently used, but is reserved for the
- future (leave it NULL). Note that changing the attributes
- does not imply that a subsequent refresh will update the
- screen to match, since the character values are not modi-
- fied. Use touchwin to force the screen to match the
- updated attributes.
-
- Attributes
+ color argument is a color-pair index (as in the first ar-
+ gument of init_pair, see curs_color(3x)). The opts argu-
+ ment is not presently used, but is reserved for the future
+ (leave it NULL).
+
+
+
The following video attributes, defined in <curses.h>, can
be passed to the routines attron, attroff, and attrset, or
- OR'ed with the characters passed to addch.
-
- A_NORMAL Normal display (no highlight)
- A_STANDOUT Best highlighting mode of the terminal.
- A_UNDERLINE Underlining
- A_REVERSE Reverse video
- A_BLINK Blinking
- A_DIM Half bright
- A_BOLD Extra bright or bold
- A_PROTECT Protected mode
- A_INVIS Invisible or blank mode
- A_ALTCHARSET Alternate character set
- A_CHARTEXT Bit-mask to extract a character
- COLOR_PAIR(n) Color-pair number n
+ OR'd with the characters passed to addch (see curs_add-
+ ch(3x)).
+
+ NameDescription
+ ------------------------------------------------------------
+ A_NORMAL Normal display (no highlight)
+ A_STANDOUT Best highlighting mode of the terminal.
+ A_UNDERLINE Underlining
+ A_REVERSE Reverse video
+ A_BLINK Blinking
+ A_DIM Half bright
+ A_BOLD Extra bright or bold
+ A_PROTECT Protected mode
+ A_INVIS Invisible or blank mode
+ A_ALTCHARSET Alternate character set
+ A_ITALIC Italics (non-X/Open extension)
+
+ A_CHARTEXT Bit-mask to extract a character
+ COLOR_PAIR(n) Color-pair number n
+
+ These video attributes are supported by attr_on and relat-
+ ed functions (which also support the attributes recognized
+ by attron, etc.):
+
+ NameDescription
+ -----------------------------------------
+ WA_HORIZONTAL Horizontal highlight
+ WA_LEFT Left highlight
+ WA_LOW Low highlight
+ WA_RIGHT Right highlight
+ WA_TOP Top highlight
+ WA_VERTICAL Vertical highlight
+
+ For consistency
The following macro is the reverse of COLOR_PAIR(n):
PAIR_NUMBER(attrs) Returns the pair number associated
with the COLOR_PAIR(n) attribute.
- The return values of many of these routines are not mean-
+ The return values of many of these routines are not mean-
ingful (they are implemented as macro-expanded assignments
- and simply return their argument). The SVr4 manual page
+ and simply return their argument). The SVr4 manual page
claims (falsely) that these routines always return 1.
-
NOTES
- Note that attroff, wattroff, attron, wattron, attrset,
+
+ Note that attroff, wattroff, attron, wattron, attrset,
wattrset, standend and standout may be macros.
+ COLOR_PAIR values can only be OR'd with attributes if the
+ pair number is less than 256. The alternate functions
+ such as color_set can pass a color pair value directly.
+ However, ncurses ABI 4 and 5 simply OR this value within
+ the alternate functions. You must use ncurses ABI 6 to
+ support more than 256 color pairs.
+
-
PORTABILITY
- All these functions are supported in the XSI Curses stan-
- dard, Issue 4. The standard defined the dedicated type
- for highlights, attr_t, which is not defined in SVr4
- curses. The functions taking attr_t arguments are not sup-
- ported under SVr4.
-
- The XSI Curses standard states that whether the tradi-
- tional functions attron/attroff/attrset can manipulate
- attributes other than A_BLINK, A_BOLD, A_DIM, A_REVERSE,
+
+ These functions are supported in the XSI Curses standard,
+ Issue 4. The standard defined the dedicated type for
+ highlights, attr_t, which is not defined in SVr4 curses.
+ The functions taking attr_t arguments are not supported
+ under SVr4.
+
+ The XSI Curses standard states that whether the tradition-
+ al functions attron/attroff/attrset can manipulate at-
+ tributes other than A_BLINK, A_BOLD, A_DIM, A_REVERSE,
A_STANDOUT, or A_UNDERLINE is "unspecified". Under this
implementation as well as SVr4 curses, these functions
correctly manipulate all other highlights (specifically,
A_ALTCHARSET, A_PROTECT, and A_INVIS).
+ This implementation provides the A_ITALIC attribute for
+ terminals which have the enter_italics_mode (sitm) and ex-
+ it_italics_mode (ritm) capabilities. Italics are not men-
+ tioned in X/Open Curses. Unlike the other video at-
+ tributes, I_ITALIC is unrelated to the set_attributes ca-
+ pabilities. This implementation makes the assumption that
+ exit_attribute_mode may also reset italics.
+
XSI Curses added the new entry points, attr_get, attr_on,
- attr_off, attr_set, wattr_on, wattr_off, wattr_get,
- wattr_set. These are intended to work with a new series
- of highlight macros prefixed with WA_.
-
- WA_NORMAL Normal display (no highlight)
- WA_STANDOUT Best highlighting mode of the terminal.
- WA_UNDERLINE Underlining
- WA_REVERSE Reverse video
- WA_BLINK Blinking
- WA_DIM Half bright
- WA_BOLD Extra bright or bold
- WA_ALTCHARSET Alternate character set
+ attr_off, attr_set, wattr_on, wattr_off, wattr_get, wat-
+ tr_set. These are intended to work with a new series of
+ highlight macros prefixed with WA_. The older macros have
+ direct counterparts in the newer set of names:
+
+ NameDescription
+ ------------------------------------------------------------
+ WA_NORMAL Normal display (no highlight)
+ WA_STANDOUT Best highlighting mode of the terminal.
+ WA_UNDERLINE Underlining
+ WA_REVERSE Reverse video
+ WA_BLINK Blinking
+ WA_DIM Half bright
+ WA_BOLD Extra bright or bold
+ WA_ALTCHARSET Alternate character set
+
+ Very old versions of this library did not force an update
+ of the screen when changing the attributes. Use touchwin
+ to force the screen to match the updated attributes.
The XSI curses standard specifies that each pair of corre-
- sponding A_ and WA_-using functions operates on the same
+ sponding A_ and WA_-using functions operates on the same
current-highlight information.
The XSI standard extended conformance level adds new high-
lights A_HORIZONTAL, A_LEFT, A_LOW, A_RIGHT, A_TOP, A_VER-
- TICAL (and corresponding WA_ macros for each) which this
- curses does not yet support.
+ TICAL (and corresponding WA_ macros for each). As of Au-
+ gust 2013, no known terminal provides these highlights
+ (i.e., via the sgr1 capability).
+
+
+
+ All routines return the integer OK on success, or ERR on
+ failure.
+
+ X/Open does not define any error conditions.
+
+ This implementation returns an error if the window pointer
+ is null. The wcolor_set function returns an error if the
+ color pair parameter is outside the range 0..COL-
+ OR_PAIRS-1. This implementation also provides getattrs
+ for compatibility with older versions of curses.
+
+ Functions with a "mv" prefix first perform a cursor move-
+ ment using wmove, and return an error if the position is
+ outside the window, or if the window pointer is null.