Mdthbs

I'm reading the manual page terminfo and I wonder if the Linux console may
use the terminal type linux-16color instead of the terminal type linux.

prompt% infocmp linux linux-16color

comparing linux to linux-16color.

comparing booleans.

comparing numbers.

colors: 8, 16.

ncv: 18, 42.

pairs: 64, 256.

comparing strings.

setab: 'E[4%p1%dm', 'E[4%p1%{8}%m%d%?%p1%{7}%>%t;5%e;25%;m'.

setaf: 'E[3%p1%dm', 'E[3%p1%{8}%m%d%?%p1%{7}%>%t;1%e;21%;m'.

I replaced the terminal typelinux in /etc/inittab by linux-16color but the Linux console seems to display only eight colors. I thought the terminal type linux-16color could be specified to display sixteen colors, concerning the Linux console. I have also tried to set the environment variable TERM to linux-16color without success.

Can the Linux console display sixteen colors? Can the Linux console support the terminal type linux-16color?

See Also

• Terminal code (ANSI/VT100)

The linux-16color terminal description uses the console's blink- and bold-attributes to map codes 0-15 into the 16 colors that the console is capable of doing. In the description, that is done using the 5 vs 25 and 1 vs 21 constants in the setaf and setab capabilities which you may notice in the console_codes(4) manual page.

You might find it easier to see using the -f option of infocmp:

    setab=E[4 

            %p1%{8}%m%d 

            %? 

                    %p1%{7}%> 

                    %t;5 

            %e 

                    ;25 

            %; 

            m,

The sequence (reading top to bottom) does this:

• sends an ASCII escape (the E) followed by [ and 4
  


• checks if the first parameter is greater than 7
  
  
  
  
  • if yes, sends ; (a delimiter) and 5 (the blink attribute)
  
  
  • if no, sends ; 2 5 to turn blink off)
  
  
  
  


• finishes the SGR by sending m
  

Those attributes happen to work with VGA drivers which don't (generally) cause the text to blink, or use a different font to show bold text. Instead, they allow extending the set of colors (in a nonstandard manner, of course). If you have a different display device (such as the virtual machines I work with), none of that applies anymore.

There's a complication since that was set up: configurations which load a Unicode-capable font (i.e., 512 glyphs versus the original 256) take over one of the bits used for those 16 colors, so you really only get 8 colors. That's mentioned here and there this for example, but was introduced since the manual page was last updated:

Due to the use of a 512-glyph LatArCyrHeb-16 font in the previous example, bright colors are no longer available on the Linux console unless a framebuffer is used. If one wants to have bright colors without framebuffer and can live without characters not belonging to his language, it is still possible to use a language-specific 256-glyph font, as illustrated below: