Developing Attractive non-GUI Apps for Unix?

Lysol asks: "Many years ago I wrote a POS (Point of Sale System) in a language (that's amazingly still around) called PowerBasic. One thing I really liked about it was the ability to do inline assembly and compile to machine code, which was a very big deal for DOS-based Basic code. For my POS app I used many text graphic libraries that gave me a poor-mans GUI for DOS. Now I'm going back to school and I need to brush up on my C, and that got me thinking about developing it in Linux. When I deployed this system it ran on old 386 machines. A lot of newer systems run on expensive hardware and it would be cool to provide a free GPL POS on Linux that can function as aterminal/text based solution. If you've ever used a cash register, sometimes GUI stuff with a mouse is not the best...especially for end users." One only has to look at FreshMeat to find examples of text UI libraries (and I'm sure that list isn't a complete one), but which ones have you used that you found enjoyable to develop in? How easy would it be to develop a text-mode application that has a UI that is just as capable as any GUI?

"I first want to deploy it using a terminal interface instead of a GUI interface for the simple reason that there will be times when it's better to run thin machines without installing X11, and it might be easier to implement rather than jumping right into GTK or some X11 widget toolkit. So does anyone know of any character based UI libraries that are available for C?"

Comments

Re:wussies

[double_h]

You sissies and your monitors...why don't you program like real men, using flashing LEDs to let you know what's going on.

Ahh, you too have no idea how coddled and pampered you really are. When I learned to code, LEDs weren't yet in widespread use, and all of the computers used HEDs (heat emitting diodes) for status displays. The only way to tell if a bit was set was to touch a HED and see if your fingers got burned. It was no fun at all coming off of an all-night hacking binge with my fingers covered in tiny pinpoint-sized burns from a particularly gruelling debugging session, only to go to work for twelve hours manufacturing watch springs in a dangerous sweatshop just so I could afford the computer time and a bit of coal to fuel young Timmy's iron lung.

I'm just glad I wasn't there the night that some fool decided to mess around with the system clock multiplier, causing all the HEDs to set fire to the console, burning down not only the data center but also two adjacent nursing homes and a Salvation Army warehouse used to store surplus 72oz cans of bean w/bacon soup.

Reservoir Zigs

Linux POS System

[SirShadowlord]

Ah, none other than the Jamie Zawinski (of netscape/Mozilla/Lucid Emacs fame) has been working on this particular problem.

Check out:
http://www.dnalounge.com/backstage/log/2001/02.htm l

Where Jamie provides a pointer to:

http://www.linuxcanada.com/linuxpos.html

He also took a swipe at hacking up his own Linux based POS system:

http://www.dnalounge.com/backstage/src/pos/

Ncurses Programming

[KidSock]

How easy would it be to develop a text-mode application that has a UI that is just as capable as any GUI?

Quite easy actually. I've been doing a lot of ncurses programming lately. You can do some amazinly elaborate things with it if your a good programmer. A good technique really pays. If you start running into situations where you're brute-forcing it, I advise that you back off and do a little work on a good "framework" for your app(that's one minus about ncurses, there's very little "flamework").

Some key points about ncurses:

o It's very fast - Text mode applications are great for productivity. Their GUI counterparts always turn out to be slower for some reason.
o Menus and Forms - The menu and form libraries are standard on UNIXes. You can fairly easily create fields for data entry that have built in validation routines ...etc.
o Tables - Well, not exactly, but a clever way to make a very snappy table is to just use a menu. In text mode you can't tell the differnce. Ncurses menu-tables are more than what the Java 1.1 AWT library provides
o Well established - Curses programming has been around for a long time. The characteristics of many terminal types has been worked out(by ESR) and abstracted into the terminfo database. Its quite portable.
o Works Anywhere - You can run it over telnet, ssh, or just dump bulky X alltogether and run on the Linux console.

Here's some links:

Ncurses Intro by Eric S. Raymond and Zeyd M. Ben-Halim
Linux Journal Artical by ESR
Fujitsu ETI Programmers Guide
SCO ETI Programming

I really wish people would concentrate more ncurses programs. They're just damn efficient. Anyone who uses mutt and slrn and such knows what I'm talking about. If you're really clever, you'll librarify whatever it is that your working on so you can hook on a GUI version later after you've tweeked the behavior of the app without wasting a lot of clock-cycles on graphics programming.