I am trying to write a C program using the netsnmp library for system observation over a network. I'd like to know more details on this. Can someone help me with this?
I suggest you read the netsnmp tutorials. This one shows you how to query a device once you know the ip address. Start simple and work up to multiple devices.
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i want to create new library for my e-paper using atmega32 and eclipse enviroment. What do i have to know about it moreover how it works. I dont want to use arduino libraries, want to write it on my own. How to best start making it? I know how to use SPI, what commands do i have to send to display, but do i have to have any drivers which are necessarily? Is any possibilty to program it using only this module:
https://www.waveshare.com/1.54inch-e-paper-module-b.htm
and SPI? Or it is necessary to have some drivers to do it?
Your question a little bit strange, because "driver" is usually piece of code, written by a third person. So, answer is yes - it is always possible to do it from scratch, without using third-side software.
First what you need to know is what type of controller being used in that display, to get technical documentation (datasheet). Unfortunately, there is no such information, but there is a link to the specification document: https://www.waveshare.com/w/upload/9/9e/1.54inch-e-paper-b-specification.pdf
Read it carefully. For example at page 8 you can find the list of commands, which are used to control the display, and below the detailed description of the commands.
At pages 24, 25 you can find initialization sequence, and reference flowchart.
If any doubts, you can download and investigate how third-party libraries are done. For example here: https://github.com/waveshare/e-Paper
A little background, I'm a CMPE Student currently in an Operating Systems class. I have some basic knowledge of C coding but am more comfortable with C++ (taken about 3 semesters of that). Other than that, never had any other formal training in coding. Also, I've got a basic understanding of the linux environment.
I am working on a project that requires me and my team to code a linux kernel module that can do the following:
echoes data passed from user-level processes by printing the data received to the kernel log
is able to pass data from one user process to another.
must be possible to use the kernel module as an inter-process communication abstraction. module should provide for situations where a sender posts data to it but no receiver is waiting.module must cover the situation where a receiver asks for data but there is no data available.
module must cover the situation where a receiver asks for data but there is no data available.
must be a limit in the buffer capacity in your module.
Now I don't know how difficult this seems to those with a background in programming, but this seems like an impossibly complicated task for someone in my position.
Here's what I've done so far:
Coded, Compiled, Inserted, and Removed the basic "hello world" linux kernel module successfully
Read through about the first 4 or 5 chapters of The Linux Kernel Module Programming Guide
Read through a few stackoverflow posts, none of which seem to be able to direct me to where I need to go.
So finally here's my question: Can someone please point me in the direction that I need to go with this? I don't even know where to being to find commands to use for reading in user-level process data and I need somewhere to start me off. TLPD was great for insight on the topic but isn't helping me get to the point where I will have a workable project to turn in. In the past, I would learn off of reading source code and reverse engineering, is there anywhere I can find something like that? Any and all help is appreciated.
-Will
I've found that the Linux Kernel Module Programming Guide is a pretty good resource. From the sounds of it, something like a character device might work best for your purposes, but I'm not sure if you have other constraints.
Another direction I might consider (though this could be a bad path) is to look at examples in the Linux kernel for a kernel module that has similar functionality. I don't have a good example offhand, but perhaps look through /drivers/char/.
What you describe is pretty much the same as a pipe.
Read chapter three of Linux Device Drivers.
(But don't just copy the scull pipe example …)
I am trying to write a code that can get the names of the installed drivers in my Windows computer in C (via winapi)?
I am really new to C and I do not know what I can do ? Can you please help me with this situation ?
Thank you very much
You need the setup API. Start with this article: How to enumerate hardware devices by using SetupDi calls
I am working on project where I need to print a receipt through a Hengstler C51 Thermal Printer. The device is working fine and it's printing images too.
I need to write a C program which can open my printer and print my preformatted receipt which is going to contain a simple logo.
I can not figure out how to proceed.
The API Documentations given by Hengstler really stinks. I installed all their drivers and API libs though. I am using Ubuntu 11.04.
I am looking for some sample or demo programs to start from.
might just be easier to make program that creates your image file instead of programming the printer. I can't find anything on this thing. Your best bet is to trial and error on that API and Docs they provide, if you don't like my idea.
I'm trying to write program to work as programmable directory, in other words: User, or other systems open that directory and read/write files or dirs. I try to create program to cache most used files in memory (less I/O to HDD), but right now I don't know how to achive that. There are probably some docs about this but I can't find them. I know that there is FUSE, NFS and others, but reading their source is quite difficult. If any one has info about implementation in C lang I'll be very grateful.
Sorry for my English..
FUSE has a C interface - take a look at their Hello World example.
If you want a simple implementation, try Python's FUSE library. A quick tutorial can be found here.
You could have a look at the GIO library — it's part of GTK, but can be used separately. The documentation is pretty thorough, and if you need to do some quick prototyping you can use the PyGTK GIO bindings to mess around before going back and writing it in C.
It's licensed under the LGPL.
If you find it easier to code in Python, it's possible to create a compiled program using cx_Freeze.