curs_color(3)						     Library Functions Manual						     curs_color(3)

NAME

       curs_color, start_color, init_pair, init_color, has_colors, can_change_color, color_content, pair_content, COLOR_PAIR, COLOR_PAIRS, COLORS,
       PAIR_NUMBER - Curses color-manipulation routines and variables

SYNOPSIS

       # include <curses.h>

       int start_color(
	       void ); int init_pair(
	       short pair,
	       short f,
	       short b ); int init_color(
	       short color,
	       short r,
	       short g,
	       short b ); bool has_colors(
	       void ); bool can_change_color(
	       void ); int color_content(
	       short color,
	       short *r,
	       short *g,
	       short *b ); int pair_content(
	       short pair,
	       short *f,
	       short *b ); int COLOR_PAIR(
	       int n ); int PAIR_NUMBER(
	       int value );

LIBRARY

       Curses Library (libcurses)

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       start_color, init_pair, init_color, has_colors, can_change_color, color_content, pair_content, COLOR_PAIR, PAIR_NUMBER:	XCURSES4.2

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION

       The Curses library includes routines that manipulate color-on-color alphanumeric terminals. To use these routines, applications	must  call
       start_color,  usually  right  after initscr. Colors are always used in pairs (referred to as color-pairs). A color-pair consists of a fore-
       ground color (for characters) and a background color (for the field on which the characters are displayed). An application calls  init_pair
       to initialize a color-pair. After the color-pair is initialized, applications can call COLOR_PAIR(n) to use color attributes.

       If  a  terminal is capable of redefining colors, applications can use the routine init_color to change the definition of a color.  The rou-
       tines has_colors and can_change_color return TRUE or FALSE, depending on whether the terminal has color capabilities and whether the appli-
       cation can change the colors. The routine color_content allows an application to identify the amounts of red, green, and blue components in
       an initialized color. The routine pair_content allows the application to find out how a given color-pair is currently defined.

   Routine Descriptions
       The start_color routine requires no arguments. It must be called if the application uses colors, and before the application calls any other
       color  manipulation  routine. It is good practice to call this routine right after initscr. The start_color routine initializes eight basic
       colors (black, red, green, yellow, blue, magenta, cyan, and white) and two global variables (COLORS  and  COLOR_PAIRS,  which  respectively
       define the maximum number of colors and color-pairs the terminal can support). The start_color routine also restores the colors on the ter-
       minal to the values they had when the terminal was turned on.

       The init_pair routine changes the definition of a color-pair. This routine takes three arguments that are identification  numbers  for  the
       following: The color-pair to be changed The foreground color The background color

       The  value  of the first argument must be between 1 and the smaller of either 63 or COLOR_PAIRS-1. The values of the second and third argu-
       ments must be between 0 and COLORS. If the color-pair was previously initialized, the screen is	refreshed  and	all  occurrences  of  that
       color-pair are changed to the new definition.

       The init_color routine changes the definition of a color. This routine 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, respectively). The value of the first argument must be	between  0
       and  COLORS.  (See the subsection 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, the routine 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; oth-
       erwise, the routine 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. This routine
       requires four arguments: the color number, and three addresses (of short data type) for storing the information about the amounts  of  red,
       green,  and blue components 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 which colors a given color-pair consists of. This routine requires three  arguments:  the
       color-pair  number,  and  two addresses (of short data type) for storing the numbers for the foreground and background colors. The value of
       the first argument must be between 1 and the smaller of 63 or COLOR_PAIRS-1. The values that are stored at the addresses pointed to by  the
       second and third arguments are between 0 and COLORS.

       The  COLOR_PAIR(n) macro returns the value of the color-pair whose number is n.	This value is the color attribute as it would be extracted
       from a chtype variable.	Conversely, the macro PAIR_NUMBER(value) returns the number of the color-pair associated with the color  attribute
       value.

   Colors
       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.

       COLOR_BLACK COLOR_RED COLOR_GREEN COLOR_YELLOW COLOR_BLUE COLOR_MAGENTA COLOR_CYAN COLOR_WHITE

NOTES

       The header file <curses.h> automatically includes the header file <stdio.h>.

       Note that COLOR_PAIR and PAIR_NUMBER may be macros.

RETURN VALUES

       The COLOR_PAIR, PAIR_NUMBER, can_change_color, and has_colors routines return values as indicated in the DESCRIPTION section.

       All other routines return ERR upon failure and OK upon successful completion.

SEE ALSO

       Functions: curses(3), curs_attr_get(3), curs_initscr(3)

       Others: standards(5)

																     curs_color(3)