hey friends, i have registered to this site first time.
well i want to start project on unix emulator.
the main objective is : unix server and windows clients.
then provide printing facilities to all windows clients using TCP/IP protocol.

so please give me basic information about unix emulator.
what is it?
how it works?
architecture?



uma

you want to write a unix emulator to run on a windows box to serve windows clients with printing services?

You won't be able to write en emulator that runs on windows, it's as simple as that. There are too many aspects of unix are handled differently in windows... device access, memory protection etc...

What you could do is write something that translates unix function calls to their windows equivalents. Someone has already done this though... it's called CygWin.

Maybe I'm misunderstanding your question though... can you provide more detail?

Is this a joke? you want to write an "emulator" without any idea of how unix works in the slightest???? I'd wonder if you're even really aware of what an emulator actually is...

Designing and writing an emulator for unix is no small undertaking. In order to even begin, you must familiarise yourself with the entire kernel. I've read some of it, but we're talking about 26MB of code here... it'll take you a year and then some to read it and even begin to understand it.
Then you'd have to contend with the fact that the only OS that will successfully host a unix emulator is unix.
I'll be honest... I've been a system programmer for a long time (~13 years) and I wouldn't even consider attempting something like this.

Windows/Unix printer sharing. How about Samba.

hello,DIYLinux
thanks for ur reply.But my friend i have to design the emulator and hence i want some required information that's how other emulator works for the same job

Thanking you,
u4u

Like we've said, writing a UNIX emulator is a VERY hard and VERY complex thing.... there's no way we can possibly tell you how tyo make one, not least because we don't know.

Maybe you're looking to do something like this:

http://www.cygwin.com/

Good luck....

Basically what an emulator does is act as a translator for system calls.
Picture the following situation:
unix program running on an emulator on windows wants to read from the hard drive. It calls the relevant function in the unix kernel. The kernel then attempts to access the relevant piece of hardware. This access is instead directed to the emulator. The emulator then converts this to a windows call and passes it to the windows kernel (which probably crashes ) which does the access and then the return value gets passed back through the same sequence (except in reverse).
In order for this to happen, the emulator must transparently intercept all calls and handle them legally. This would require examining the unix kernel and handling every possible call with either a windows equivalent or a fake event.
CygWin is not really en emulator, more of a Windows library for running specially written Win32/Unix programs. You can't just get a linux/unix binary and expect CygWin to handle it.