curs_color(3CURSES) Curses Library Functions curs_color(3CURSES)
curs_color, start_color, init_pair, init_color, has_colors, can_change_color, color_content, pair_content - curses color manipulation rou-
cc [ flag ... ] file ... -lcurses [ library ... ]
int init_pair(short pair, short fg, short bg);
int init_color(short color, short red, short green, short blue);
int color_content(short color, short *redp, short *greenp, short *bluep);
int pair_content(short pair, short *fgp, short *bgp);
curses provides routines that manipulate color on color alphanumeric terminals. To use these routines start_color() must be called, usu-
ally right after initscr(). See curs_initscr(3CURSES). Colors are always used in pairs (referred to as color-pairs). A color-pair consists
of a foreground color (for characters) and a background color (for the field on which the characters are displayed). A programmer initial-
izes a color-pair with the routine init_pair. After it has been initialized, COLOR_PAIR(n), a macro defined in <curses.h>, can be used in
the same ways other video attributes can be used. If a terminal is capable of redefining colors, the programmer can use the routine
init_color() to change the definition of a color. The routines has_colors() and can_change_color() return TRUE or FALSE, depending on
whether the terminal has color capabilities and whether the programmer can change the colors. The routine color_content() allows a program-
mer to identify the amounts of red, green, and blue components in an initialized color. The routine pair_content() allows a programmer to
find out how a given color-pair is currently defined.
The start_color() routine requires no arguments. It must be called if the programmer wants to use colors, and before any other color manip-
ulation routine is called. It is good practice to call this routine right after initscr(). start_color() initializes eight basic colors
(black, red, green, yellow, blue, magenta, cyan, and white), and two global variables, COLORS and COLOR_PAIRS (respectively defining the
maximum number of colors and color-pairs the terminal can support). It also restores the colors on the terminal to the values they had when
the terminal was just turned on.
The init_pair() routine changes the definition of a color-pair. It takes three arguments: the number of the color-pair to be changed, the
foreground color number, and the background color number. The value of the first argument must be between 1 and COLOR_PAIRS-1. The value of
the second and third arguments must be between 0 and COLORS. If the color-pair was previously initialized, the screen is refreshed and all
occurrences of that color-pair is changed to the new definition.
The init_color() routine changes the definition of a color. It takes four arguments: the number of the color to be changed followed by
three RGB values (for the amounts of red, green, and blue components). The value of the first argument must be between 0 and COLORS. (See
the section Colors for the default color index.) Each of the last three arguments must be a value between 0 and 1000. When init_color() is
used, all occurrences of that color on the screen immediately change to the new definition.
The has_colors() routine requires no arguments. It returns TRUE if the terminal can manipulate colors; otherwise, it returns FALSE. This
routine facilitates writing terminal-independent programs. For example, a programmer can use it to decide whether to use color or some
other video attribute.
The can_change_color() routine requires no arguments. It returns TRUE if the terminal supports colors and can change their definitions;
other, it returns FALSE. This routine facilitates writing terminal-independent programs.
The color_content() routine gives users a way to find the intensity of the red, green, and blue (RGB) components in a color. It requires
four arguments: the color number, and three addresses of shorts for storing the information about the amounts of red, green, and blue com-
ponents in the given color. The value of the first argument must be between 0 and COLORS. The values that are stored at the addresses
pointed to by the last three arguments are between 0 (no component) and 1000 (maximum amount of component).
The pair_content() routine allows users to find out what colors a given color-pair consists of. It requires three arguments: the color-pair
number, and two addresses of shorts for storing the foreground and the background color numbers. The value of the first argument must be
between 1 and COLOR_PAIRS-1. The values that are stored at the addresses pointed to by the second and third arguments are between 0 and
In <curses.h> the following macros are defined. These are the default colors. curses also assumes that COLOR_BLACK is the default back-
ground color for all terminals.
All routines that return an integer return ERR upon failure and OK upon successful completion.
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|MT-Level |Unsafe |
curs_attr(3CURSES), curs_initscr(3CURSES), curses(3CURSES), attributes(5)
The header <curses.h> automatically includes the headers <stdio.h> and <unctrl.h>.
SunOS 5.10 31 Dec 1996 curs_color(3CURSES)