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+<H1>curs_color 3x</H1>
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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
+ <STRONG>start_color</STRONG>, <STRONG>init_pair</STRONG>, <STRONG>init_color</STRONG>, <STRONG>has_colors</STRONG>,
+ <STRONG>can_change_color</STRONG>, <STRONG>color_content</STRONG>, <STRONG>pair_content</STRONG>, <STRONG>COLOR_PAIR</STRONG>
+ - <STRONG>curses</STRONG> 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>
+ <STRONG>#</STRONG> <STRONG>include</STRONG> <STRONG><curses.h></STRONG>
+
+ <STRONG>int</STRONG> <STRONG>start_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>
+ <STRONG>bool</STRONG> <STRONG>has_colors(void);</STRONG>
+ <STRONG>bool</STRONG> <STRONG>can_change_color(void);</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>
</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
+ <STRONG>Overview</STRONG>
+ <STRONG>curses</STRONG> support color attributes on terminals with that ca-
+ pability. 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>,
+ pair with the routine <STRONG>init_pair</STRONG>. After it has been ini-
+ tialized, <STRONG>COLOR_PAIR</STRONG>(<EM>n</EM>), a macro defined in <STRONG><curses.h></STRONG>,
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
+ 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
- <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
+ 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.
+
+ <STRONG>Routine</STRONG> <STRONG>Descriptions</STRONG>
+ 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 <B>initscr</B>.
- <B>start_color</B> initializes eight basic colors (black, red,
+ good practice to call this routine right after <STRONG>initscr</STRONG>.
+ <STRONG>start_color</STRONG> 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
+ global variables, <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</STRONG> (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-
+ 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:
- - The value of the first argument must be between <B>1</B> and
- <B>COLOR_PAIRS-1</B>.
+ <STRONG>o</STRONG> The value of the first argument must be between <STRONG>1</STRONG> and
+ <STRONG>COLOR_PAIRS-1</STRONG>, except that 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 background.
- - 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).
+ <STRONG>o</STRONG> The value of the second and third arguments must be
+ between 0 and <STRONG>COLORS</STRONG>. Color pair 0 is assumed to be
+ white on black, but is actually whatever the terminal
+ implements before color is initialized. It cannot be
+ modified by the application.
- If the color-pair was previously initialized, the screen
- is refreshed and all occurrences of that color-pair is
+ 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 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
+ As an extension, ncurses allows you to set color pair 0
+ via the <STRONG>assume_default_colors</STRONG> routine, or to specify the
+ use of default colors (color number <STRONG>-1</STRONG>) if you first in-
+ voke the <STRONG>use_default_colors</STRONG> routine.
+
+ 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). The value of the first
+ argument must be between <STRONG>0</STRONG> and <STRONG>COLORS</STRONG>. (See the section
+ <STRONG>Colors</STRONG> for the default color index.) Each of the last
+ three arguments must be a value between 0 and 1000. When
+ <STRONG>init_color</STRONG> 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.
+ 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.
- 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
+ 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.
- The <B>color_content</B> routine gives programmers a way to find
+ 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 <B>short</B>s for storing the information
+ 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. 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).
+ between 0 and <STRONG>COLORS</STRONG>. The values that are stored at the
+ addresses pointed to by the last three arguments are be-
+ tween 0 (no component) and 1000 (maximum amount of compo-
+ nent).
- The <B>pair_content</B> routine allows programmers to find out
+ 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 <B>short</B>s for storing the foreground and the background
+ of <STRONG>short</STRONG>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
+ between 1 and <STRONG>COLOR_PAIRS-1</STRONG>. The values that are stored
at the addresses pointed to by the second and third argu-
- ments are between 0 and <B>COLORS</B>.
+ ments are between 0 and <STRONG>COLORS</STRONG>.
- <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>
+ <STRONG>Colors</STRONG>
+ In <STRONG><curses.h></STRONG> the following macros are defined. These are
+ the default colors. <STRONG>curses</STRONG> also assumes that <STRONG>COLOR_BLACK</STRONG>
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>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>
</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 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 <B>ERR</B> upon failure and
- an <B>OK</B> (SVr4 specifies only "an integer value other than
- <B>ERR</B>") upon successful completion.
+ 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 0 to COLORS-1 (except for the default colors ex-
+ tension), or use color pairs outside the range 0 to COL-
+ OR_PAIRS-1. Color values used in <STRONG>init_color</STRONG> must be in
+ the range 0 to 1000. 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 <EM>initialize</EM><STRONG>_</STRONG><EM>color</EM> 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>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.
+ In the <EM>ncurses</EM> implementation, there is a separate color
+ activation flag, color palette, color pairs table, and as-
+ sociated COLORS and COLOR_PAIRS 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
+ mind, and historical implementations may use a single
shared color palette.
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>.
+ 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 <STRONG><A HREF="curs_bkgd.3x.html">curs_bkgd(3x)</A></STRONG>.
- Several caveats apply on 386 and 486 machines with VGA-
+ Several caveats apply on 386 and 486 machines with VGA-
compatible graphics:
- - COLOR_YELLOW is actually brown. To get yellow, use
- COLOR_YELLOW combined with the <B>A_BOLD</B> attribute.
+ <STRONG>o</STRONG> COLOR_YELLOW is actually brown. To get yellow, use
+ COLOR_YELLOW combined with the <STRONG>A_BOLD</STRONG> attribute.
- - 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).
+ <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).
- - Color RGB values are not settable.
+ <STRONG>o</STRONG> Color RGB values are not settable.
</PRE>
<H2>PORTABILITY</H2><PRE>
- This implementation satisfies XSI Curses's minimum maxi-
- mums for <B>COLORS</B> and <B>COLOR_PAIRS</B>.
+ This implementation satisfies XSI Curses's minimum maxi-
+ mums for <STRONG>COLORS</STRONG> and <STRONG>COLOR_PAIRS</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.
+ The <STRONG>init_pair</STRONG> routine accepts negative values of fore-
+ ground and background color to support the <STRONG>use_de-</STRONG>
+ <STRONG>fault_colors</STRONG> extension, but only if that routine has been
+ first invoked.
- 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,
+ The assumption that <STRONG>COLOR_BLACK</STRONG> is the default background
+ color for all terminals can be modified using the <STRONG>as-</STRONG>
+ <STRONG>sume_default_colors</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.
</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>default_col-</B>
- <B><A HREF="ors.3x.html">ors(3x)</A></B>
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
+ <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>