NAME | SYNOPSIS | DESCRIPTION | VIDEO ATTRIBUTES | NOTES | EXTENSIONS | PORTABILITY | RETURN VALUE | SEE ALSO | COLOPHON

curs_attr(3X)                                                  curs_attr(3X)

NAME         top

       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

SYNOPSIS         top

       #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);

DESCRIPTION         top

       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.

   Window attributes
       There are two sets of functions:

       ·   functions for manipulating the window attributes and color:
           wattr_set and wattr_get.

       ·   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 other attributes.  Use
       attr_off and wattr_off to turn off window attributes, again values
       OR'd together in attr, without affecting other attributes.

   Legacy window 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 arguments 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)).

   Change character rendition
       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 perform 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 function 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)).

   Change window color
       The routine color_set sets the current color of the given window to
       the foreground/background combination described by the color pair
       parameter.

   Standout
       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

       ·   they have well established legacy use, and

       ·   there is no ambiguity about the way the attributes might be
           combined with a color pair.

VIDEO ATTRIBUTES         top

       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_addch(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 related 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 meaningful (they
       are implemented as macro-expanded assignments and simply return their
       argument).  The SVr4 manual page claims (falsely) that these routines
       always return 1.

NOTES         top

       These functions may be macros:

              attroff, wattroff, attron, wattron, attrset, wattrset,
              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.

EXTENSIONS         top

       This implementation provides the A_ITALIC attribute for terminals
       which have the enter_italics_mode (sitm) and exit_italics_mode (ritm)
       capabilities.  Italics are not mentioned in X/Open Curses.  Unlike
       the other video attributes, A_ITALIC is unrelated to the
       set_attributes capabilities.  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 parameter in ABI 6 for the functions which
       have a color-pair parameter to support extended color pairs:

       ·   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.

       ·   For functions which retrieve the color, e.g., wattr_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 manipulate color,
       e.g., wattr_on and wattr_off are not used by this implementation
       except to check that they are NULL.

PORTABILITY         top

       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 traditional functions
       attron/attroff/attrset can manipulate attributes 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 corresponding A_
       and WA_-using functions operates on the same current-highlight
       information.

       The XSI standard extended conformance level adds new highlights
       A_HORIZONTAL, A_LEFT, A_LOW, A_RIGHT, A_TOP, A_VERTICAL (and
       corresponding WA_ macros for each).  As of August 2013, no known
       terminal provides these highlights (i.e., via the sgr1 capability).

RETURN VALUE         top

       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.

       ·   returns an error if the color pair parameter for wcolor_set is
           outside the range 0..COLOR_PAIRS-1.

       ·   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 movement using
       wmove, and return an error if the position is outside the window, or
       if the window pointer is null.

SEE ALSO         top

       curses(3X), curs_addch(3X), curs_addstr(3X), curs_bkgd(3X),
       curs_printw(3X), curs_variables(3X)

COLOPHON         top

       This page is part of the ncurses (new curses) project.  Information
       about the project can be found at 
       ⟨https://www.gnu.org/software/ncurses/ncurses.html⟩.  If you have a
       bug report for this manual page, send it to
       bug-ncurses-request@gnu.org.  This page was obtained from the
       project's upstream Git mirror of the CVS repository 
       ⟨git://ncurses.scripts.mit.edu/ncurses.git⟩ on 2017-09-15.  If you
       discover any rendering problems in this HTML version of the page, or
       you believe there is a better or more up-to-date source for the page,
       or you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

                                                               curs_attr(3X)