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<PRE>
-<!-- Manpage converted by man2html 3.0.1 -->
+<STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG> <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
-</PRE>
-<H2>NAME</H2><PRE>
- <B>start_color</B>, <B>init_pair</B>, <B>init_color</B>, <B>has_colors</B>,
- <B>can_change_color</B>, <B>color_content</B>, <B>pair_content</B>, <B>COLOR_PAIR</B>
- - <B>curses</B> color manipulation routines
-</PRE>
-<H2>SYNOPSIS</H2><PRE>
- <B>#</B> <B>include</B> <B><curses.h></B>
- <B>int</B> <B>start_color(void);</B>
- <B>int</B> <B>init_pair(short</B> <B>pair,</B> <B>short</B> <B>f,</B> <B>short</B> <B>b);</B>
- <B>int</B> <B>init_color(short</B> <B>color,</B> <B>short</B> <B>r,</B> <B>short</B> <B>g,</B> <B>short</B> <B>b);</B>
- <B>bool</B> <B>has_colors(void);</B>
- <B>bool</B> <B>can_change_color(void);</B>
- <B>int</B> <B>color_content(short</B> <B>color,</B> <B>short</B> <B>*r,</B> <B>short</B> <B>*g,</B> <B>short</B>
- <B>*b);</B>
- <B>int</B> <B>pair_content(short</B> <B>pair,</B> <B>short</B> <B>*f,</B> <B>short</B> <B>*b);</B>
+</PRE><H2><a name="h2-NAME">NAME</a></H2><PRE>
+ <STRONG>start_color</STRONG>, <STRONG>has_colors</STRONG>, <STRONG>can_change_color</STRONG>, <STRONG>init_pair</STRONG>,
+ <STRONG>init_color</STRONG>, <STRONG>color_content</STRONG>, <STRONG>pair_content</STRONG>, <STRONG>COLOR_PAIR</STRONG>,
+ <STRONG>PAIR_NUMBER</STRONG> - <STRONG>curses</STRONG> color manipulation routines
-</PRE>
-<H2>DESCRIPTION</H2><PRE>
- <B>Overview</B>
- <B>curses</B> support color attributes on terminals with that
- capability. To use these routines <B>start_color</B> must be
- called, usually right after <B>initscr</B>. Colors are always
- used in pairs (referred to as color-pairs). A color-pair
- consists of a foreground color (for characters) and a
+
+</PRE><H2><a name="h2-SYNOPSIS">SYNOPSIS</a></H2><PRE>
+ <STRONG>#include</STRONG> <STRONG><curses.h></STRONG>
+
+ <STRONG>int</STRONG> <STRONG>start_color(void);</STRONG>
+
+ <STRONG>bool</STRONG> <STRONG>has_colors(void);</STRONG>
+ <STRONG>bool</STRONG> <STRONG>can_change_color(void);</STRONG>
+
+ <STRONG>int</STRONG> <STRONG>init_pair(short</STRONG> <STRONG>pair,</STRONG> <STRONG>short</STRONG> <STRONG>f,</STRONG> <STRONG>short</STRONG> <STRONG>b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>init_color(short</STRONG> <STRONG>color,</STRONG> <STRONG>short</STRONG> <STRONG>r,</STRONG> <STRONG>short</STRONG> <STRONG>g,</STRONG> <STRONG>short</STRONG> <STRONG>b);</STRONG>
+ /* extensions */
+ <STRONG>int</STRONG> <STRONG>init_extended_pair(int</STRONG> <STRONG>pair,</STRONG> <STRONG>int</STRONG> <STRONG>f,</STRONG> <STRONG>int</STRONG> <STRONG>b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>init_extended_color(int</STRONG> <STRONG>color,</STRONG> <STRONG>int</STRONG> <STRONG>r,</STRONG> <STRONG>int</STRONG> <STRONG>g,</STRONG> <STRONG>int</STRONG> <STRONG>b);</STRONG>
+
+ <STRONG>int</STRONG> <STRONG>color_content(short</STRONG> <STRONG>color,</STRONG> <STRONG>short</STRONG> <STRONG>*r,</STRONG> <STRONG>short</STRONG> <STRONG>*g,</STRONG> <STRONG>short</STRONG>
+ <STRONG>*b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>pair_content(short</STRONG> <STRONG>pair,</STRONG> <STRONG>short</STRONG> <STRONG>*f,</STRONG> <STRONG>short</STRONG> <STRONG>*b);</STRONG>
+ /* extensions */
+ <STRONG>int</STRONG> <STRONG>extended_color_content(int</STRONG> <STRONG>color,</STRONG> <STRONG>int</STRONG> <STRONG>*r,</STRONG> <STRONG>int</STRONG> <STRONG>*g,</STRONG> <STRONG>int</STRONG>
+ <STRONG>*b);</STRONG>
+ <STRONG>int</STRONG> <STRONG>extended_pair_content(int</STRONG> <STRONG>pair,</STRONG> <STRONG>int</STRONG> <STRONG>*f,</STRONG> <STRONG>int</STRONG> <STRONG>*b);</STRONG>
+
+ <STRONG>int</STRONG> <STRONG>COLOR_PAIR(int</STRONG> <STRONG>n);</STRONG>
+ <STRONG>PAIR_NUMBER(</STRONG><EM>attrs</EM><STRONG>);</STRONG>
+
+
+</PRE><H2><a name="h2-DESCRIPTION">DESCRIPTION</a></H2><PRE>
+
+</PRE><H3><a name="h3-Overview">Overview</a></H3><PRE>
+ <STRONG>curses</STRONG> supports color attributes on terminals with that
+ capability. To use these routines <STRONG>start_color</STRONG> must be
+ called, usually right after <STRONG>initscr</STRONG>. 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 blank field on which the charac-
- ters are displayed). A programmer initializes a color-
- pair with the routine <B>init_pair</B>. After it has been ini-
- tialized, <B>COLOR_PAIR</B>(<I>n</I>), a macro defined in <B><curses.h></B>,
- can be used as a new video attribute.
-
- If a terminal is capable of redefining colors, the pro-
- grammer can use the routine <B>init_color</B> to change the defi-
- nition of a color. The routines <B>has_colors</B> and
- <B>can_change_color</B> return <B>TRUE</B> or <B>FALSE</B>, depending on
- whether the terminal has color capabilities and whether
- the programmer can change the colors. The routine
- <B>color_content</B> allows a programmer to extract the amounts
- of red, green, and blue components in an initialized
- color. The routine <B>pair_content</B> allows a programmer to
- find out how a given color-pair is currently defined.
-
- <B>Routine</B> <B>Descriptions</B>
- The <B>start_color</B> routine requires no arguments. It must be
- called if the programmer wants to use colors, and before
- any other color manipulation routine is called. It is
- good practice to call this routine right after <B>initscr</B>.
- <B>start_color</B> initializes eight basic colors (black, red,
- green, yellow, blue, magenta, cyan, and white), and two
- global variables, <B>COLORS</B> and <B>COLOR_PAIRS</B> (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 <B>init_pair</B> 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. For portable applications:
+ ters are displayed). A programmer initializes a color-
+ pair with the routine <STRONG>init_pair</STRONG>. After it has been ini-
+ tialized, <STRONG>COLOR_PAIR</STRONG>(<EM>n</EM>) can be used to convert the pair to
+ a video attribute.
- - The value of the first argument must be between <B>1</B> and
- <B>COLOR_PAIRS-1</B>.
+ If a terminal is capable of redefining colors, the pro-
+ grammer can use the routine <STRONG>init_color</STRONG> to change the defi-
+ nition of a color. The routines <STRONG>has_colors</STRONG> and
+ <STRONG>can_change_color</STRONG> return <STRONG>TRUE</STRONG> or <STRONG>FALSE</STRONG>, depending on
+ whether the terminal has color capabilities and whether
+ the programmer can change the colors. The routine <STRONG>col-</STRONG>
+ <STRONG>or_content</STRONG> allows a programmer to extract the amounts of
+ red, green, and blue components in an initialized color.
+ The routine <STRONG>pair_content</STRONG> allows a programmer to find out
+ how a given color-pair is currently defined.
- - The value of the second and third arguments must be
- between 0 and <B>COLORS</B> (the 0 color pair is wired to
- white on black and cannot be changed).
- If the color-pair was previously initialized, the screen
- is refreshed and all occurrences of that color-pair is
- changed to the new definition.
+</PRE><H3><a name="h3-Color-Rendering">Color Rendering</a></H3><PRE>
+ The <STRONG>curses</STRONG> library combines these inputs to produce the
+ actual foreground and background colors shown on the
+ screen:
- As an extension, ncurses allows you to set color pair 0
- via the <B>assume_default_colors</B> routine, or to specify the
- use of default colors (color number <B>-1</B>) if you first
- invoke the <B>use_default_colors</B> routine.
-
- The <B>init_color</B> 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 <B>0</B> and <B>COLORS</B>. (See the section
- <B>Colors</B> for the default color index.) Each of the last
- three arguments must be a value between 0 and 1000. When
- <B>init_color</B> is used, all occurrences of that color on the
- screen immediately change to the new definition.
-
- The <B>has_colors</B> routine requires no arguments. It returns
- <B>TRUE</B> if the terminal can manipulate colors; otherwise, it
- returns <B>FALSE</B>. 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.
+ <STRONG>o</STRONG> per-character video attributes (e.g., via <STRONG>waddch</STRONG>),
- The <B>can_change_color</B> routine requires no arguments. It
- returns <B>TRUE</B> if the terminal supports colors and can
- change their definitions; other, it returns <B>FALSE</B>. This
- routine facilitates writing terminal-independent programs.
+ <STRONG>o</STRONG> the window attribute (e.g., by <STRONG>wattrset</STRONG>), and
- The <B>color_content</B> routine gives programmers 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 <B>short</B>s 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 <B>COLORS</B>. 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 com-
- ponent).
-
- The <B>pair_content</B> routine allows programmers to find out
- what colors a given color-pair consists of. It requires
- three arguments: the color-pair number, and two addresses
- of <B>short</B>s for storing the foreground and the background
- color numbers. The value of the first argument must be
- between 1 and <B>COLOR_PAIRS-1</B>. The values that are stored
- at the addresses pointed to by the second and third argu-
- ments are between 0 and <B>COLORS</B>.
-
- <B>Colors</B>
- In <B><curses.h></B> the following macros are defined. These are
- the default colors. <B>curses</B> also assumes that <B>COLOR_BLACK</B>
- is the default background color for all terminals.
-
- <B>COLOR_BLACK</B>
- <B>COLOR_RED</B>
- <B>COLOR_GREEN</B>
- <B>COLOR_YELLOW</B>
- <B>COLOR_BLUE</B>
- <B>COLOR_MAGENTA</B>
- <B>COLOR_CYAN</B>
- <B>COLOR_WHITE</B>
+ <STRONG>o</STRONG> the background character (e.g., <STRONG>wbkgdset</STRONG>).
+ Per-character and window attributes are usually set by a
+ parameter containing video attributes including a color
+ pair value. Some functions such as <STRONG>wattr_set</STRONG> use a sepa-
+ rate parameter which is the color pair number.
-</PRE>
-<H2>RETURN VALUE</H2><PRE>
- The routines <B>can_change_color()</B> and <B>has_colors()</B> return
- <B>TRUE</B> or <B>FALSE</B>.
+ The background character is a special case: it includes a
+ character value, just as if it were passed to <STRONG>waddch</STRONG>.
- All other routines return the integer <B>ERR</B> upon failure and
- an <B>OK</B> (SVr4 specifies only "an integer value other than
- <B>ERR</B>") upon successful completion.
+ The <STRONG>curses</STRONG> library does the actual work of combining these
+ color pairs in an internal function called from <STRONG>waddch</STRONG>:
+ <STRONG>o</STRONG> If the parameter passed to <STRONG>waddch</STRONG> is <EM>blank</EM>, and it us-
+ es the special color pair 0,
-</PRE>
-<H2>NOTES</H2><PRE>
- In the <I>ncurses</I> implementation, there is a separate color
- activation flag, color palette, color pairs table, and
- associated COLORS and COLOR_PAIRS counts for each screen;
- the <B>start_color</B> function only affects the current screen.
- The SVr4/XSI interface is not really designed with this in
- mind, and historical implementations may use a single
- shared color palette.
+ <STRONG>o</STRONG> <STRONG>curses</STRONG> next checks the window attribute.
- Note that setting an implicit background color via a color
- pair affects only character cells that a character write
- operation explicitly touches. To change the background
- color used when parts of a window are blanked by erasing
- or scrolling operations, see <B><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></B>.
+ <STRONG>o</STRONG> If the window attribute does not use color pair 0,
+ <STRONG>curses</STRONG> uses the color pair from the window at-
+ tribute.
- Several caveats apply on 386 and 486 machines with VGA-
- compatible graphics:
+ <STRONG>o</STRONG> Otherwise, <STRONG>curses</STRONG> uses the background character.
- - COLOR_YELLOW is actually brown. To get yellow, use
- COLOR_YELLOW combined with the <B>A_BOLD</B> attribute.
+ <STRONG>o</STRONG> If the parameter passed to <STRONG>waddch</STRONG> is <EM>not</EM> <EM>blank</EM>, or it
+ does not use the special color pair 0, <STRONG>curses</STRONG> prefers
+ the color pair from the parameter, if it is nonzero.
+ Otherwise, it tries the window attribute next, and fi-
+ nally the background character.
- - The A_BLINK attribute should in theory cause the
- background to go bright. This often fails to work,
- and even some cards for which it mostly works (such
- as the Paradise and compatibles) do the wrong thing
- when you try to set a bright "yellow" background (you
- get a blinking yellow foreground instead).
+ Some <STRONG>curses</STRONG> functions such as <STRONG>wprintw</STRONG> call <STRONG>waddch</STRONG>. Those
+ do not combine its parameter with a color pair. Conse-
+ quently those calls use only the window attribute or the
+ background character.
- - Color RGB values are not settable.
+</PRE><H2><a name="h2-CONSTANTS">CONSTANTS</a></H2><PRE>
+ In <STRONG><curses.h></STRONG> the following macros are defined. These are
+ the standard colors (ISO-6429). <STRONG>curses</STRONG> also assumes that
+ <STRONG>COLOR_BLACK</STRONG> is the default background color for all termi-
+ nals.
-</PRE>
-<H2>PORTABILITY</H2><PRE>
- This implementation satisfies XSI Curses's minimum maxi-
- mums for <B>COLORS</B> and <B>COLOR_PAIRS</B>.
+ <STRONG>COLOR_BLACK</STRONG>
+ <STRONG>COLOR_RED</STRONG>
+ <STRONG>COLOR_GREEN</STRONG>
+ <STRONG>COLOR_YELLOW</STRONG>
+ <STRONG>COLOR_BLUE</STRONG>
+ <STRONG>COLOR_MAGENTA</STRONG>
+ <STRONG>COLOR_CYAN</STRONG>
+ <STRONG>COLOR_WHITE</STRONG>
- The <B>init_pair</B> routine accepts negative values of fore-
- ground and background color to support the
- <B>use_default_colors</B> extension, but only if that routine has
- been first invoked.
+ Some terminals support more than the eight (8) "ANSI" col-
+ ors. There are no standard names for those additional
+ colors.
- The assumption that <B>COLOR_BLACK</B> is the default background
- color for all terminals can be modified using the
- <B>assume_default_colors</B> extension,
+</PRE><H2><a name="h2-VARIABLES">VARIABLES</a></H2><PRE>
-</PRE>
-<H2>SEE ALSO</H2><PRE>
- <B><A HREF="ncurses.3x.html">curses(3x)</A></B>, <B><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></B>, <B><A HREF="curs_attr.3x.html">curs_attr(3x)</A></B>, <B><A HREF="dft_fgbg.3x.html">dft_fgbg(3x)</A></B>
+</PRE><H3><a name="h3-COLORS">COLORS</a></H3><PRE>
+ is initialized by <STRONG>start_color</STRONG> to the maximum number of
+ colors the terminal can support.
+</PRE><H3><a name="h3-COLOR_PAIRS">COLOR_PAIRS</a></H3><PRE>
+ is initialized by <STRONG>start_color</STRONG> to the maximum number of
+ color pairs the terminal can support.
+</PRE><H2><a name="h2-FUNCTIONS">FUNCTIONS</a></H2><PRE>
+</PRE><H3><a name="h3-start_color">start_color</a></H3><PRE>
+ The <STRONG>start_color</STRONG> routine requires no arguments. It must be
+ called if the programmer wants to use colors, and before
+ any other color manipulation routine is called. It is
+ good practice to call this routine right after <STRONG>initscr</STRONG>.
+ <STRONG>start_color</STRONG> does this:
+ <STRONG>o</STRONG> It initializes two global variables, <STRONG>COLORS</STRONG> and <STRONG>COL-</STRONG>
+ <STRONG>OR_PAIRS</STRONG> (respectively defining the maximum number of
+ colors and color-pairs the terminal can support).
+ <STRONG>o</STRONG> It initializes the special color pair <STRONG>0</STRONG> to the default
+ foreground and background colors. No other color
+ pairs are initialized.
+ <STRONG>o</STRONG> It restores the colors on the terminal to the values
+ they had when the terminal was just turned on.
+ <STRONG>o</STRONG> If the terminal supports the <STRONG>initc</STRONG> (<STRONG>initialize_color</STRONG>)
+ capability, <STRONG>start_color</STRONG> initializes its internal table
+ representing the red, green and blue components of the
+ color palette.
+ The components depend on whether the terminal uses CGA
+ (aka "ANSI") or HLS (i.e., the <STRONG>hls</STRONG> (<STRONG>hue_lightness_sat-</STRONG>
+ <STRONG>uration</STRONG>) capability is set). The table is initialized
+ first for eight basic colors (black, red, green, yel-
+ low, blue, magenta, cyan, and white), and after that
+ (if the terminal supports more than eight colors) the
+ components are initialized to <STRONG>1000</STRONG>.
+ <STRONG>start_color</STRONG> does not attempt to set the terminal's
+ color palette to match its built-in table. An appli-
+ cation may use <STRONG>init_color</STRONG> to alter the internal table
+ along with the terminal's color.
+ These limits apply to color values and color pairs. Val-
+ ues outside these limits are not legal, and may result in
+ a runtime error:
+ <STRONG>o</STRONG> <STRONG>COLORS</STRONG> corresponds to the terminal database's <STRONG>max_col-</STRONG>
+ <STRONG>ors</STRONG> capability, (see <STRONG><A HREF="max_colterminfo.5.html">terminfo(5)</A></STRONG>).
+ <STRONG>o</STRONG> color values are expected to be in the range <STRONG>0</STRONG> to <STRONG>COL-</STRONG>
+ <STRONG>ORS-1</STRONG>, inclusive (including <STRONG>0</STRONG> and <STRONG>COLORS-1</STRONG>).
+ <STRONG>o</STRONG> a special color value <STRONG>-1</STRONG> is used in certain extended
+ functions to denote the <EM>default</EM> <EM>color</EM> (see <STRONG>use_de-</STRONG>
+ <STRONG>fault_colors</STRONG>).
+ <STRONG>o</STRONG> <STRONG>COLOR_PAIRS</STRONG> corresponds to the terminal database's
+ <STRONG>max_pairs</STRONG> capability, (see <STRONG><A HREF="terminfo.5.html">terminfo(5)</A></STRONG>).
+ <STRONG>o</STRONG> legal color pair values are in the range <STRONG>1</STRONG> to <STRONG>COL-</STRONG>
+ <STRONG>OR_PAIRS-1</STRONG>, inclusive.
+ <STRONG>o</STRONG> color pair <STRONG>0</STRONG> is special; it denotes "no color".
+ Color pair <STRONG>0</STRONG> is assumed to be white on black, but is
+ actually whatever the terminal implements before color
+ is initialized. It cannot be modified by the applica-
+ tion.
+</PRE><H3><a name="h3-has_colors">has_colors</a></H3><PRE>
+ The <STRONG>has_colors</STRONG> routine requires no arguments. It returns
+ <STRONG>TRUE</STRONG> if the terminal can manipulate colors; otherwise, it
+ returns <STRONG>FALSE</STRONG>. This routine facilitates writing terminal-
+ independent programs. For example, a programmer can use
+ it to decide whether to use color or some other video at-
+ tribute.
+
+
+</PRE><H3><a name="h3-can_change_color">can_change_color</a></H3><PRE>
+ The <STRONG>can_change_color</STRONG> routine requires no arguments. It
+ returns <STRONG>TRUE</STRONG> if the terminal supports colors and can
+ change their definitions; other, it returns <STRONG>FALSE</STRONG>. This
+ routine facilitates writing terminal-independent programs.
+
+
+</PRE><H3><a name="h3-init_pair">init_pair</a></H3><PRE>
+ The <STRONG>init_pair</STRONG> 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. For portable applications:
+
+ <STRONG>o</STRONG> The first argument must be a legal color pair value.
+ If default colors are used (see <STRONG>use_default_colors</STRONG>)
+ the upper limit is adjusted to allow for extra pairs
+ which use a default color in foreground and/or back-
+ ground.
+
+ <STRONG>o</STRONG> The second and third arguments must be legal color
+ values.
+
+ If the color-pair was previously initialized, the screen
+ is refreshed and all occurrences of that color-pair are
+ changed to the new definition.
+ As an extension, ncurses allows you to set color pair <STRONG>0</STRONG>
+ via the <STRONG><A HREF="default_colors.3x.html">assume_default_colors(3x)</A></STRONG> routine, or to specify
+ the use of default colors (color number <STRONG>-1</STRONG>) if you first
+ invoke the <STRONG><A HREF="default_colors.3x.html">use_default_colors(3x)</A></STRONG> routine.
+</PRE><H3><a name="h3-init_color">init_color</a></H3><PRE>
+ The <STRONG>init_color</STRONG> 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).
+ <STRONG>o</STRONG> The first argument must be a legal color value; de-
+ fault colors are not allowed here. (See the section
+ <STRONG>Colors</STRONG> for the default color index.)
+
+ <STRONG>o</STRONG> Each of the last three arguments must be a value in
+ the range <STRONG>0</STRONG> through <STRONG>1000</STRONG>.
+
+ When <STRONG>init_color</STRONG> is used, all occurrences of that color on
+ the screen immediately change to the new definition.
+
+
+</PRE><H3><a name="h3-color_content">color_content</a></H3><PRE>
+ The <STRONG>color_content</STRONG> routine gives programmers 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 <STRONG>short</STRONG>s for storing the information
+ about the amounts of red, green, and blue components in
+ the given color.
+
+ <STRONG>o</STRONG> The first argument must be a legal color value, i.e.,
+ <STRONG>0</STRONG> through <STRONG>COLORS-1</STRONG>, inclusive.
+
+ <STRONG>o</STRONG> The values that are stored at the addresses pointed to
+ by the last three arguments are in the range <STRONG>0</STRONG> (no
+ component) through <STRONG>1000</STRONG> (maximum amount of component),
+ inclusive.
+
+
+</PRE><H3><a name="h3-pair_content">pair_content</a></H3><PRE>
+ The <STRONG>pair_content</STRONG> routine allows programmers to find out
+ what colors a given color-pair consists of. It requires
+ three arguments: the color-pair number, and two addresses
+ of <STRONG>short</STRONG>s for storing the foreground and the background
+ color numbers.
+
+ <STRONG>o</STRONG> The first argument must be a legal color value, i.e.,
+ in the range <STRONG>1</STRONG> through <STRONG>COLOR_PAIRS-1</STRONG>, inclusive.
+
+ <STRONG>o</STRONG> The values that are stored at the addresses pointed to
+ by the second and third arguments are in the range <STRONG>0</STRONG>
+ through <STRONG>COLORS</STRONG>, inclusive.
+
+
+</PRE><H3><a name="h3-PAIR_NUMBER">PAIR_NUMBER</a></H3><PRE>
+ <STRONG>PAIR_NUMBER(</STRONG><EM>attrs</EM>) extracts the color value from its <EM>attrs</EM>
+ parameter and returns it as a color pair number.
+
+
+</PRE><H3><a name="h3-COLOR_PAIR">COLOR_PAIR</a></H3><PRE>
+ Its inverse <STRONG>COLOR_PAIR(</STRONG><EM>n</EM><STRONG>)</STRONG> converts a color pair number to
+ an attribute. Attributes can hold color pairs in the
+ range 0 to 255. If you need a color pair larger than
+ that, you must use functions such as <STRONG>attr_set</STRONG> (which pass
+ the color pair as a separate parameter) rather than the
+ legacy functions such as <STRONG>attrset</STRONG>.
+
+
+</PRE><H2><a name="h2-RETURN-VALUE">RETURN VALUE</a></H2><PRE>
+ The routines <STRONG>can_change_color</STRONG> and <STRONG>has_colors</STRONG> return <STRONG>TRUE</STRONG>
+ or <STRONG>FALSE</STRONG>.
+
+ All other routines return the integer <STRONG>ERR</STRONG> upon failure and
+ an <STRONG>OK</STRONG> (SVr4 specifies only "an integer value other than
+ <STRONG>ERR</STRONG>") upon successful completion.
+
+ X/Open defines no error conditions. This implementation
+ will return <STRONG>ERR</STRONG> on attempts to use color values outside
+ the range <STRONG>0</STRONG> to <STRONG>COLORS</STRONG>-1 (except for the default colors ex-
+ tension), or use color pairs outside the range <STRONG>0</STRONG> to <STRONG>COL-</STRONG>
+ <STRONG>OR_PAIRS-1</STRONG>. Color values used in <STRONG>init_color</STRONG> must be in
+ the range <STRONG>0</STRONG> to <STRONG>1000</STRONG>. An error is returned from all func-
+ tions if the terminal has not been initialized. An error
+ is returned from secondary functions such as <STRONG>init_pair</STRONG> if
+ <STRONG>start_color</STRONG> was not called.
+
+ <STRONG>init_color</STRONG>
+ returns an error if the terminal does not support
+ this feature, e.g., if the <STRONG>initialize_color</STRONG> capa-
+ bility is absent from the terminal description.
+
+ <STRONG>start_color</STRONG>
+ returns an error if the color table cannot be al-
+ located.
+
+
+</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
+ In the <STRONG>ncurses</STRONG> implementation, there is a separate color
+ activation flag, color palette, color pairs table, and as-
+ sociated <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> counts for each screen;
+ the <STRONG>start_color</STRONG> function only affects the current screen.
+ The SVr4/XSI interface is not really designed with this in
+ mind, and historical implementations may use a single
+ shared color palette.
+
+ Setting an implicit background color via a color pair af-
+ fects only character cells that a character write opera-
+ tion explicitly touches. To change the background color
+ used when parts of a window are blanked by erasing or
+ scrolling operations, see <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>.
+
+ Several caveats apply on older x86 machines (e.g., i386,
+ i486) with VGA-compatible graphics:
+
+ <STRONG>o</STRONG> COLOR_YELLOW is actually brown. To get yellow, use
+ COLOR_YELLOW combined with the <STRONG>A_BOLD</STRONG> attribute.
+
+ <STRONG>o</STRONG> The A_BLINK attribute should in theory cause the back-
+ ground to go bright. This often fails to work, and
+ even some cards for which it mostly works (such as the
+ Paradise and compatibles) do the wrong thing when you
+ try to set a bright "yellow" background (you get a
+ blinking yellow foreground instead).
+
+ <STRONG>o</STRONG> Color RGB values are not settable.
+
+
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ This implementation satisfies XSI Curses's minimum maxi-
+ mums for <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG>.
+
+ The <STRONG>init_pair</STRONG> routine accepts negative values of fore-
+ ground and background color to support the <STRONG>use_de-</STRONG>
+ <STRONG><A HREF="use_default_colors.3x.html">fault_colors(3x)</A></STRONG> extension, but only if that routine has
+ been first invoked.
+ The assumption that <STRONG>COLOR_BLACK</STRONG> is the default background
+ color for all terminals can be modified using the <STRONG>as-</STRONG>
+ <STRONG><A HREF="assume_default_colors.3x.html">sume_default_colors(3x)</A></STRONG> extension.
+ This implementation checks the pointers, e.g., for the
+ values returned by <STRONG>color_content</STRONG> and <STRONG>pair_content</STRONG>, and
+ will treat those as optional parameters when null.
+ X/Open Curses does not specify a limit for the number of
+ colors and color pairs which a terminal can support. How-
+ ever, in its use of <STRONG>short</STRONG> for the parameters, it carries
+ over SVr4's implementation detail for the compiled termin-
+ fo database, which uses signed 16-bit numbers. This im-
+ plementation provides extended versions of those functions
+ which use <STRONG>short</STRONG> parameters, allowing applications to use
+ larger color- and pair-numbers.
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <STRONG><A HREF="ncurses.3x.html">curses(3x)</A></STRONG>, <STRONG><A HREF="curs_initscr.3x.html">curs_initscr(3x)</A></STRONG>, <STRONG><A HREF="curs_attr.3x.html">curs_attr(3x)</A></STRONG>, <STRONG>curs_vari-</STRONG>
+ <STRONG><A HREF="curs_variables.3x.html">ables(3x)</A></STRONG>, <STRONG><A HREF="default_colors.3x.html">default_colors(3x)</A></STRONG>
+ <STRONG><A HREF="curs_color.3x.html">curs_color(3x)</A></STRONG>
</PRE>
-<HR>
-<ADDRESS>
-Man(1) output converted with
-<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
-</ADDRESS>
+<div class="nav">
+<ul>
+<li><a href="#h2-NAME">NAME</a></li>
+<li><a href="#h2-SYNOPSIS">SYNOPSIS</a></li>
+<li><a href="#h2-DESCRIPTION">DESCRIPTION</a>
+<ul>
+<li><a href="#h3-Overview">Overview</a></li>
+<li><a href="#h3-Color-Rendering">Color Rendering</a></li>
+</ul>
+</li>
+<li><a href="#h2-CONSTANTS">CONSTANTS</a></li>
+<li><a href="#h2-VARIABLES">VARIABLES</a>
+<ul>
+<li><a href="#h3-COLORS">COLORS</a></li>
+<li><a href="#h3-COLOR_PAIRS">COLOR_PAIRS</a></li>
+</ul>
+</li>
+<li><a href="#h2-FUNCTIONS">FUNCTIONS</a>
+<ul>
+<li><a href="#h3-start_color">start_color</a></li>
+<li><a href="#h3-has_colors">has_colors</a></li>
+<li><a href="#h3-can_change_color">can_change_color</a></li>
+<li><a href="#h3-init_pair">init_pair</a></li>
+<li><a href="#h3-init_color">init_color</a></li>
+<li><a href="#h3-color_content">color_content</a></li>
+<li><a href="#h3-pair_content">pair_content</a></li>
+<li><a href="#h3-PAIR_NUMBER">PAIR_NUMBER</a></li>
+<li><a href="#h3-COLOR_PAIR">COLOR_PAIR</a></li>
+</ul>
+</li>
+<li><a href="#h2-RETURN-VALUE">RETURN VALUE</a></li>
+<li><a href="#h2-NOTES">NOTES</a></li>
+<li><a href="#h2-PORTABILITY">PORTABILITY</a></li>
+<li><a href="#h2-SEE-ALSO">SEE ALSO</a></li>
+</ul>
+</div>
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