Multiple processes

hi there, i am new to this so thankyou for helping me out!

i am trying to implement a simple printer queue simulation using 2 processes. the first will create a series of child processes with the PID of each process being inserted into a priority queue.

the second process (running in a separate window) needs to simulate the de-spooling process including deleting a printer job by priority order and killing the corresponding process.

Can anyone help me out with some example code? i am not very competent with C Programming, so any advice is gratefully received

Many thanks

The first thing you may want to tell us is what platform you're using.

thankyou for your reply

i am using Ubuntu 7.10. Do you need any other information?

Many thanks

Then you'll want to look into fork and the exec* family of functions.

You will also need to know about "pipes".

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Mats

thankyou

i have been looking into this all day and i have realised that i need to use fork to create the child processes and i will need a pipe to connect the two main processes i need, however i am not very good with C (as you can tell!), and i don't really know how to put it all together

any more advice would be great, many thanks

If I went to a mechanic and asked:
Ok, I'm not very good with repairng cars - maybe you could tell me how I can replace my pistons in my car?

What do you think the answer would be?

You are not suggesting a SIMPLE application. Writing a multiprocessing print server is complicated. Not a beginner task. You will have to learn the basics first.

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Mats

Well to get started u think Beej IPC tutorial would be help ful to you. Even through its more about inter process communication. He still speak about process and pipes stuff.

ssharish

thanks ssharish, that tutorial is excellent and has helped a lot

The request for assistance with the printer queue simulation is, I believe, from one of my students.

I am the University lecturer that set this problem as part of the assessment for one of the modules that will lead to a degree.

I am grateful that some of you have given pointers to web sites that may give help BUT I ask that you do no more.

I know that the task is challenging - quite intentionally.

Oooh burn, discovered ;) -- Shame you probably won't know if it is one of your students, even if you did, you probably wouldn't know which one :)

Before jumping straight into the task I'd write a few 'dummy' applications first (proof-of-concepts if you will). I dunno, like 2 processes communicating over a pipe?