Hello All Gr8 Linux Developers Out There,

Background

I have created a ncurses application that is suppose to run only on the Linux's virtual console. This application will heavily utilize the ncurses windows to show window-based UI to the user. I am using CentOS5.x. The terminal for the virtual console is set to (TERM=linux).

I used the following code sequence to initialize the ncurses environment

initscr();
    getmaxyx(stdscr,y,x);

    noecho();
    cbreak();
    start_color();

    init_color(3,700,700,700);
    clear();
    wclear(stdscr);

The Issue

Currently I am unable to render solid borders in my windows. Ncurses produces solid borders for the windows using extended ASCII characters. Since I am unable to make ncurses to use extended characters, I assume I must have missing some setting in my code (may be using termios API). Currently I am fully rely on the ncurses to setup my virtual console to render solid borders. I have also tried my applications on other platform such as Fedora Core 10, and again it fails to render solid borders. However, when I run it on any pseudo terminal (using PuTTY) where TERM=xterm, it clearly renders the solid borders as I like. So I presume that there is something with the terminal type and/or driver.

Question

Kindly state what should I do to enable extended character support on my virtual terminal(console) so that ncurses can render solid borders for my windows. Or if there is any code that I should add to my application that will enables my virtual terminal (/dev/tty1) to show extended characters letting nucurses to draw solid borders.

Thanks
Kashif Ali Siddiqui
Another Linux Developer striving to become a gr8 developer

It would appear that your current terminal type (linux) may have the capabilities for solid colors. Run infocmp linux to see what your actual capabilities are. The terminfo man page will help you figure these out.

When I ran the infocmp command, it shows the following output

#	Reconstructed via infocmp from file: /usr/share/terminfo/l/linux
linux|linux console, 
	am, bce, ccc, eo, mir, msgr, xenl, xon, 
	colors#8, it#8, ncv#18, pairs#64, 
	acsc=+\020\,\021-\030.^Y0\333`\004a\261f\370g\361h\260i\316j\331k\277l\332m\300n\305o~p\304q\304r\304s_t\303u\264v\301w\302x\263y\363z\362{\343|\330}\234~\376, 
	bel=^G, blink=\E[5m, bold=\E[1m, civis=\E[?25l\E[?1c, 
	clear=\E[H\E[J, cnorm=\E[?25h\E[?0c, cr=^M, 
	csr=\E[%i%p1%d;%p2%dr, cub1=^H, cud1=^J, cuf1=\E[C, 
	cup=\E[%i%p1%d;%p2%dH, cuu1=\E[A, cvvis=\E[?25h\E[?8c, 
	dch=\E[%p1%dP, dch1=\E[P, dim=\E[2m, dl=\E[%p1%dM, 
	dl1=\E[M, ech=\E[%p1%dX, ed=\E[J, el=\E[K, el1=\E[1K, 
	flash=\E[?5h\E[?5l$<200/>, home=\E[H, hpa=\E[%i%p1%dG, 
	ht=^I, hts=\EH, ich=\E[%p1%d@, ich1=\E[@, il=\E[%p1%dL, 
	il1=\E[L, ind=^J, 
	initc=\E]P%p1%x%p2%{256}%*%{1000}%/%02x%p3%{256}%*%{1000}%/%02x%p4%{256}%*%{1000}%/%02x, 
	invis=\E[8m, kb2=\E[G, kbs=\177, kcbt=\E[Z, kcub1=\E[D, 
	kcud1=\E[B, kcuf1=\E[C, kcuu1=\E[A, kdch1=\E[3~, 
	kend=\E[4~, kf1=\E[[A, kf10=\E[21~, kf11=\E[23~, 
	kf12=\E[24~, kf13=\E[25~, kf14=\E[26~, kf15=\E[28~, 
	kf16=\E[29~, kf17=\E[31~, kf18=\E[32~, kf19=\E[33~, 
	kf2=\E[[B, kf20=\E[34~, kf3=\E[[C, kf4=\E[[D, kf5=\E[[E, 
	kf6=\E[17~, kf7=\E[18~, kf8=\E[19~, kf9=\E[20~, 
	khome=\E[1~, kich1=\E[2~, kmous=\E[M, knp=\E[6~, kpp=\E[5~, 
	kspd=^Z, nel=^M^J, oc=\E]R, op=\E[39;49m, rc=\E8, rev=\E[7m, 
	ri=\EM, rmacs=\E[10m, rmam=\E[?7l, rmir=\E[4l, 
	rmpch=\E[10m, rmso=\E[27m, rmul=\E[24m, rs1=\Ec\E]R, 
	sc=\E7, setab=\E[4%p1%dm, setaf=\E[3%p1%dm, 
	sgr=\E[0;10%?%p1%t;7%;%?%p2%t;4%;%?%p3%t;7%;%?%p4%t;5%;%?%p5%t;2%;%?%p6%t;1%;%?%p7%t;8%;%?%p9%t;11%;m, 
	sgr0=\E[0;10m, smacs=\E[11m, smam=\E[?7h, smir=\E[4h, 
	smpch=\E[11m, smso=\E[7m, smul=\E[4m, tbc=\E[3g, 
	u6=\E[%i%d;%dR, u7=\E[6n, u8=\E[?6c, u9=\E[c, 
	vpa=\E[%i%p1%dd, 

So kindly state so my virtual console can show extended characters (and enables ncurses to draw solid borders), and if so, then how can I do it.

Thanks.

• Kashif

First, while in a VT, please invoke one of the system config scripts ending with "-tui" (text user interface) which are located in /usr/sbin. Is the screen output correct or not? Solid lines, etc?

Yes, I tried the /usr/sbin/authconfig-tui, and it did give me the solid border UI, that I failed to achieve throu ncurses. Kindly state what should I do to get solid borders in my application windows.

Thanks
Kashif

Anyone please.

I really need to know how can I make my ncurses to draw solid lines.

Kashif

What is the code you're using to try to draw the solid lines? Are you using the ACS constants defined by NCurses, or are you just writing out extended-ASCII character codes?

You might want to check out some existing source code that does this - for instance, the "menuconfig" code in the Linux kernel (/usr/src/linux/scripts/kconfig/lxdialog/) - grep for ACS and you can find where it is done.

Using the ACS constants from the ncurses header is the portable solution, it will work correctly or fail gracefully on different types of terminals as long as they're set up correctly.

If you really find using ACS constants too complicated, there's an alternate option: there's a character attribute constant defined in ncurses.h called "A_ALTCHARSET". When this attribute is active, it will allow you to write out characters from the whole PC character set range - including those glyphs associated with control characters and those in the upper half of the character set. This solution is not portable, however - it's only for text consoles on PCs.

Now, I don't know if this information will solve your problem. I haven't tested this stuff. If you want me to help you further, try this stuff out. If it still doesn't work then you can provide more information about what your code is doing, and maybe I can help you out.

authconfig-tui uses curses. That means that your TERM setting is OK and the problem is in your code.

Can you share your code with us?