From: "John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: colored text in text mode
Date: Fri, 06 Dec 1996 20:04:21 -0800
Organization: Three pounds of chaos and a pinch of salt
Lines: 146
Message-ID: <32A8EC5A.1BB4@cs.com>
References: <275252745D AT fs2 DOT mt DOT umist DOT ac DOT uk>
Reply-To: fighteer AT cs DOT com
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To: "A.Appleyard" <A DOT APPLEYARD AT fs2 DOT mt DOT umist DOT ac DOT uk>
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

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A.Appleyard wrote:
> 
> In v1, and in v2, when writing to screen in the ordinary text mode by fprint()
> etc, how can I tell the PC to start writing with such-and-such a foreground
> and background color?

If you're using printf()/fprintf() to write to the screen, then there is
no standard way to change colors.  You have two choices:

Best:  Convert all the output code in your program to use the <conio.h>
functions, which support all sorts of fun stuff like colors, windows,
etc.  However, unless you convert your entire program to use <conio>,
you risk some nasty problems.

  Example:

   /* Set text color to bright blue on black. */
   /* Formula:  ( blink [0-1] << 7 ) + ( bg [0-7] ) << 4 + fg [0-15] */
   textattr( ( 0x0 << 7 ) + ( 0x0 << 4 ) + 0x9 );
   cprintf( "Hello there!\n" );

Easiest:  Load ANSI.SYS in your CONFIG.SYS, and use ANSI escape
sequences in your printf() strings.  This is quick and relatively
painless, once you learn the ANSI codes.  However, it _requires_ the
presence of ANSI.SYS on the host computer to work, so it is both awkward
and very non-portable.  

  Example:

   /* Set text color to bright blue on black. */
   /* See MS-DOS help for ANSI.SYS for syntax of ESC sequences. */
   printf( "\033[0;1;34;40m" );   /* \033 is the ESC character */
   printf( "Hello there!\n" );

Attached is a brief program that illustrates the use of conio functions
to display colored text.  Enjoy!

-- 
---------------------------------------------------------------------
| John M. Aldrich, aka Fighteer I |        fighteer AT cs DOT com          |
| Proud owner of what might one   |   http://www.cs.com/fighteer    |
| day be a spectacular MUD...     | Plan: To make Bill Gates suffer |
---------------------------------------------------------------------

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <conio.h>

void show_usage         ( const char * );

int main( int argc, char **argv )
{
    char msg[1024];
    char blink, bg, fg;
    int i;

    srandom( (int) time( 0 ) );
    blink = random( ) % 2;
    bg = random( ) % 8;
    fg = random( ) % 16;
    
    if ( argc > 1 )
        if ( !isdigit( argv[1][0] ) ||
             ( blink = atoi( argv[1] ) ) < 0 || blink > 1 )
        {
            show_usage( argv[0] );
            exit( 1 );
        }
    if ( argc > 2 )
        if ( !isdigit( argv[2][0] ) ||
             ( bg = atoi( argv[2] ) ) < 0 || bg > 7 )
        {
            show_usage( argv[0] );
            exit( 1 );
        }
    if ( argc > 3 )
        if ( !isdigit( argv[3][0] ) ||
             ( fg = atoi( argv[3] ) ) < 0 || fg > 15 )
        {
            show_usage( argv[0] );
            exit( 1 );
        }

    /* Grab text from command line? */
    strcpy( msg, "Hello there!" );
    for ( i = 4; i < argc; i++ )
    {
        if ( i == 4 )
            strcpy( msg, argv[i] );
        else
            strcat( msg, argv[i] );
        strcat( msg, " " );
    }

    textattr( ( blink << 7 ) + ( bg << 4 ) + fg );
    cprintf( "%s\n", msg );

    return 0;
}

void show_usage( const char *progname )
{
    fprintf( stderr, "\

Sets the text color to the color values indicated on the command line, and
displays a string in that color.  If no text is specified, \"Hello, there!\"
is printed.  If any colors are omitted, their value is randomly selected from
all available values.

Usage:  %s [ blink [ bg [ fg [ text ... ]]]]

    blink       Blinking text [0 - 1]
            0 : normal
            1 : blinking

    bg          Background color [0 - 7]
            0 : black                   4 : red 
            1 : blue                    5 : magenta
            2 : green                   6 : yellow
            3 : cyan                    7 : white

    fg          Foreground color [0 - 15]
            Uses same colors as background.  Add 8 to the number
            for high-intensity text.
"
             , progname );

    return;
}

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