*nix port programming in C

K
this is what I need
I need to be able to do simple port programming of my serial port I have a book that give me the basics for windows but its programs are not portable and I want to use *nix cause it give complete controll over the ports unlike XP. and co.
any way any sites or books would be helpfull
btw I did google for it but the thing either goes over my head or requires me to install a specific compiler and so I dont use them since I am trying to learn by removing that level of abstratction they limit what information I can get
I have already done the basics of both serial and paralell and know a decent amount of it
any help will be much appreciated
thank you
(ps: any inline asm code is acceptable for my requirements but could you please use ansi C ..? or is it not possible any way please elt me know)

Hi

Essentially, in Linux you can access the serial ports /dev/ttyS?
(generic name) like a file, ie you get a filedescriptor with open(),
you write to it with fputc(), you close it with close(). The difficulty
lies in the proper choice of the settings and the communication
options.
Once, I wrote a controller program for a model railway, and
the device specification were not complete - or I did not understand
it properly - it took me ages to avoid the trains crashing all the time :D

Since you know the basics, have a look at linux.com-HOWTO's[1,2].
But I suggest you to analyse a serial port test program[3] step by step,
which compiles perfectly using

Code:

---

> gcc -o com com.c

---

with a default installation of some linux distribution. Go through the
source code, and try to understand what they are doing.
You can use the program to send bit's to tty2, or you might try to
"cp /dev/ttyS1 /dev/tty2" in a virtual console and check, whether
the communication works (I have not tested this, but from what I
remember...), or connect two PC's with a null-modem cable.

Notabene: I am not going to discuss the level of abstraction in
the approach I suggested here, nor do I comment on the "control"
over the ports provided by various OS's. Depending on the amount
of time you want to spend into your project, I would recommend
to use the environment you are most familiar with.

Cheers


[1] http://www.linux.com/howtos/Serial-HOWTO.shtml#toc11
[2] http://www.linux.com/howtos/Serial-P...TO/index.shtml
[3] http://www.comptechdoc.org/os/linux/...pgcserial.html