curs_attr(3x) curs_attr(3x)
attr_get, wattr_get, attr_set, wattr_set, attr_off,
wattr_off, attr_on, wattr_on, attroff, wattroff, attron,
wattron, attrset, wattrset, chgat, wchgat, mvchgat,
mvwchgat, color_set, wcolor_set, standend, wstandend,
standout, wstandout - curses character and window
attribute control routines
#include <curses.h>
int attr_get(attr_t *attrs, short *pair, void *opts);
int wattr_get(WINDOW *win, attr_t *attrs, short *pair,
void *opts);
int attr_set(attr_t attrs, short pair, void *opts);
int wattr_set(WINDOW *win, attr_t attrs, short pair, void
*opts);
int attr_off(attr_t attrs, void *opts);
int wattr_off(WINDOW *win, attr_t attrs, void *opts);
int attr_on(attr_t attrs, void *opts);
int wattr_on(WINDOW *win, attr_t attrs, void *opts);
int attroff(int attrs);
int wattroff(WINDOW *win, int attrs);
int attron(int attrs);
int wattron(WINDOW *win, int attrs);
int attrset(int attrs);
int wattrset(WINDOW *win, int attrs);
int chgat(int n, attr_t attr, short pair, const void
*opts);
int wchgat(WINDOW *win,
int n, attr_t attr, short pair, const void *opts);
int mvchgat(int y, int x,
int n, attr_t attr, short pair, const void *opts);
int mvwchgat(WINDOW *win, int y, int x,
int n, attr_t attr, short pair, const void *opts);
int color_set(short pair, void* opts);
int wcolor_set(WINDOW *win, short pair, void* opts);
int standend(void);
int wstandend(WINDOW *win);
int standout(void);
int wstandout(WINDOW *win);
These routines manipulate the current attributes of the
named window, which then apply to all characters that are
written into the window with waddch, 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.
These routines do not affect the attributes used when
erasing portions of the window. See curs_bkgd(3x) for
functions which modify the attributes used for erasing and
clearing.
Routines which do not have a WINDOW* parameter apply to
stdscr. For example, attr_set is the stdscr variant of
wattr_set.
There are two sets of functions:
o functions for manipulating the window attributes and
color: wattr_set and wattr_get.
o functions for manipulating only the window attributes
(not color): wattr_on and wattr_off.
The wattr_set function sets the current attributes of the
given window to attrs, with color specified by pair.
Use wattr_get to retrieve attributes for the given window.
Use attr_on and wattr_on to turn on window attributes,
i.e., values OR'd together in attr, without affecting oth-
er attributes. Use attr_off and wattr_off to turn off
window attributes, again values OR'd together in attr,
without affecting other attributes.
Most of the window attribute routines are extensions of
older routines which assume that color pairs are OR'd into
the attribute parameter. These older routines use the
same name, omitting an underscore (_).
The attrset routine is a legacy feature predating SVr4
curses but kept in X/Open Curses for the same reason that
SVr4 curses kept it: compatibility.
The remaining attr* functions operate exactly like the
corresponding attr_* functions, except that they take ar-
guments of type int rather than attr_t.
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-
form wrapping. A character count of -1 or greater than
the remaining window width means to change attributes all
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 pair argument is a color-
pair index (as in the first argument of init_pair, see
curs_color(3x)).
The routine color_set sets the current color of the given
window to the foreground/background combination described
by the color pair parameter.
The routine standout is the same as attron(A_STANDOUT).
The routine standend is the same as attrset(A_NORMAL) or
attrset(0), that is, it turns off all attributes.
X/Open does not mark these "restricted", because
o they have well established legacy use, and
o there is no ambiguity about the way the attributes
might be combined with a color pair.
The following video attributes, defined in <curses.h>, can
be passed to the routines attron, attroff, and attrset, or
OR'd with the characters passed to addch (see curs_add-
ch(3x)).
Name Description
-----------------------------------------------------------
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
These video attributes are supported by attr_on and relat-
ed functions (which also support the attributes recognized
by attron, etc.):
Name Description
-----------------------------------------
WA_HORIZONTAL Horizontal highlight
WA_LEFT Left highlight
WA_LOW Low highlight
WA_RIGHT Right highlight
WA_TOP Top highlight
WA_VERTICAL Vertical highlight
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
claims (falsely) that these routines always return 1.
These functions may be macros:
attroff, wattroff, attron, wattron, attrset, wat-
trset, standend and standout.
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.
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, A_ITALIC is unrelated to the set_attributes ca-
pabilities. This implementation makes the assumption that
exit_attribute_mode may also reset italics.
Each of the functions added by XSI Curses has a parameter
opts, which X/Open Curses still (after more than twenty
years) documents as reserved for future use, saying that
it should be NULL. This implementation uses that parame-
ter in ABI 6 for the functions which have a color-pair pa-
rameter to support extended color pairs:
o For functions which modify the color, e.g., wattr_set,
if opts is set it is treated as a pointer to int, and
used to set the color pair instead of the short pair
parameter.
o For functions which retrieve the color, e.g., wat-
tr_get, if opts is set it is treated as a pointer to
int, and used to retrieve the color pair as an int
value, in addition retrieving it via the standard
pointer to short parameter.
The remaining functions which have opts, but do not manip-
ulate color, e.g., wattr_on and wattr_off are not used by
this implementation except to check that they are NULL.
These functions are supported in the XSI Curses standard,
Issue 4. The standard defined the dedicated type for
highlights, attr_t, which was not defined in SVr4 curses.
The functions taking attr_t arguments were not supported
under SVr4.
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 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).
XSI Curses added these entry points:
attr_get, attr_on, attr_off, attr_set, wattr_on,
wattr_off, wattr_get, wattr_set
The new functions 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:
Name Description
------------------------------------------------------------
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
The XSI curses standard specifies that each pair of corre-
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). 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
o returns an error if the window pointer is null.
o returns an error if the color pair parameter for wcol-
or_set is outside the range 0..COLOR_PAIRS-1.
o does not return an error if either of the parameters
of wattr_get used for retrieving attribute or color-
pair values is NULL.
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.
curses(3x), curs_addch(3x), curs_addstr(3x),
curs_bkgd(3x), curs_printw(3x), curs_variables(3x)
curs_attr(3x)