Linux is a popular, open source operating system kernel. Linus Torvalds started development of the kernel in 1991.
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0answers
14 views
PHP USB serial port call from Windows to Linux
I have a piece of simple code that works on a Windows - WAMP environment, e.g.
<?php
`mode com3: BAUD=38400 PARITY=N data=8 stop=1 xon=off`;
file_put_contents(com3, ...
-1
votes
0answers
62 views
How to do simple video processing with PHP? [closed]
I've been working with PHP for a while now, but this is the first project I've done that requires video processing. Ultimately, we want to do the following:
Resize videos down so that their ...
-1
votes
0answers
20 views
Bash daemon doesn't collect its chilidren [migrated]
I've written this bash daemon that keeps an eye on a named pipe, logs everything it sees on a file named $LOG_FILE_BASENAME.$DATE, and it also creates a filtered version of it in ...
0
votes
0answers
56 views
A callback for when data is received?
So, my understanding is that the Kernel could receive TCP at any time, and that generally a C program asks the Kernel synchronously/asynchronously if it has data available. Would it be possible for a ...
1
vote
1answer
90 views
What does using pointer in Linux kernel imply?
So far I was under the perspective that while working in the kernel code, working with memory implies working with long integers and not pointers because dereferencing pointers shouldn't be done in ...
2
votes
1answer
151 views
What is the motivation for casting a pointer into a integer?
I'm doing some changes in the Linux kernel code and have noticed a pointer being cast into integer.
Check out buf below (full code):
snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream ...
1
vote
3answers
95 views
Reading file during write on linux
As I understand, when a file is being written, the process writing to the file obtains an exclusive lock. So other processes cannot access this file for read.
With the above knowledge, I'm unable ...
3
votes
1answer
79 views
Best practices for a daemon that forks and becomes user
I want to write a small daemon in python under Linux that accepts connections and authenticates the user (details for this don't matter) and then forks a child for the connection and becomes the user. ...
2
votes
1answer
87 views
Should one use many small configuration files for script or a single large configuration file?
I have a script which starts from cron with regular interval and sources in around 10 variables. Should I keep those 10 variables in one configuration file in file system or is it a better practice to ...
-5
votes
1answer
114 views
Linux on USB for Python (or other) Programming on the go? [closed]
This is my first question and I didn't see a similar question asked. Sorry if I didn't search hard enough.
To the point. I'm learning the Python programming language and I've read Linux plays very ...
-3
votes
3answers
195 views
Why should PHP developer use/learn VI editor? [closed]
Why should PHP developer use/learn VI editor ?
I mean there are 10 most amazing editors like PHPStorm, Netbeans which increases developers productivity.
Lets just consider PHPStorm. I never got ...
1
vote
1answer
115 views
How come the NSA could release SELinux as GPL when all US Gov work must be Public Domain?
I'm not sure if this is a good question for this site, but it does deal with the things to do with working as programmer.
SELinux is a security enhanced version of Linux, and was initially developed ...
0
votes
0answers
25 views
How to package a SDL2-based Linux app?
I've written a small toy application using SDL2. I want to distribute it the most user-friendly way, for Linux.
I should make a deb package, but then I should also make packages for other distros, ...
22
votes
5answers
3k views
Why don't Windows/Linux use relational Databases (RDBMS)?
Why don't Windows/Linux use relational databases (RDBMS)?
I know they use file systems to store all data but don't you think it is more efficient to use databases like we use in web sites/web apps?
...
0
votes
1answer
208 views
Are ANSI* Escape Sequences Proper For Coloring Text in Terminal(Linux)?
I just switched back to Linux after a few years of Windows use and am wondering if ANSI Escape Sequences are okay for coloring text. I ask because the way I did it on windows isn't capable of crossing ...
2
votes
1answer
63 views
Library OSes vs Unikernels
My understanding of a Hypervisor & Virtual Machines is that the hypervisor is a program (either running on top of a host OS, or running bare metal as the host) that leverages binary-compatible ...
2
votes
2answers
152 views
What are the benefits of a device driver when I can access the I/O registers directly?
I was interested in what modern, C-based, Linux device driver development looked like, and so I took a good gander at this excellent article.
I didn't read every single line, but perused the majority ...
0
votes
1answer
74 views
Memory Limit of a Single Program and mmap
If one has a 32 bit machine, a single program cannot address more than 2^32 bytes, or 4 GB. Would making use of mmap() allow one to exceed the 4 GB limit?
0
votes
0answers
126 views
Best way to signal all child processes to terminate using C
I have been assigned the task of designing a simple web server using C in my UNIX & C class. The webserver listens and forks when a successful connection is made so that multiple clients may be ...
0
votes
3answers
115 views
What is the explication for the difference execution time for the same instruction?
As you know when we run instruction in our code
like long a = b;
we will not have the same ticks each to be executed.
first exeution it take 2ticks;
second exeution it take 3ticks;
third exeution it ...
1
vote
2answers
204 views
Is Red Star OS released under the GPL? [closed]
According to Wikipedia, Red Star OS is
is a North Korean Linux-based operating system
Does that mean it's covered by the GPL, or are there exceptions?
-2
votes
3answers
300 views
Programming in Linux (C++) [closed]
So I don't know If this is the right place to ask this. I am new to programming, I am not very in to it (I know classes,arrays,functions..etc(Basic Things)).
I was programming with Visual Studio 2013 ...
1
vote
1answer
85 views
Should a bin directory be full of shell scripts? [closed]
New guy on the team so I figured I'd ask here in public than sound like a complete dweeb and ask elsewhere. Without giving too much or anything away (please ask questions if you want), but should, or ...
1
vote
3answers
150 views
Protect memory from a potentially seg faulting function call
How can one safely call a function that might segfault without corrupting the stack or the heap?
These SO questions cover using signal handlers and setjmp.h to regain control.
Coming back to life ...
0
votes
2answers
89 views
What does “host” mean in “… host driver” and “… host adapter”?
From How Linux Works, by Brian Ward, I saw "SCSI Host Adapter", "SATA Host Driver", "Disk Driver (sd)", "CD/DVD Driver (sr)", "USB Host Driver", and "USB Storage Driver".
What does "host" mean in ...
1
vote
2answers
89 views
How does a user program access a device?
In Linux, from http://www.mulix.org/lectures/intro_to_linux_device_drivers/intro_linux_device_drivers.pdf
user programs talk with device drivers through device files
But if I understand ...
1
vote
0answers
65 views
Is there a standard practice on making a modular Python script?
I wrote a Python script for PIA here: pia-auto-login.py
However, I need to make it more modular so that it does the OpenVPN changes from this script. Then I want to create two more packages (at ...
1
vote
2answers
700 views
Why doesn't Android use shared libraries?
In Android if you use a library in your app (such as the Support Library) the code for the library is duplicated on the device for each app that uses it.
Why can't android use the linux "shared ...
0
votes
1answer
100 views
What programmable system can provide persistent scheduling? [closed]
I want to write an application that creates scheduled events at specific times. When the delay elapses the event notifies the application. The scheduled events must not be stored in the application's ...
1
vote
2answers
128 views
Program Compatibility - OS That Can Run Anything? [closed]
I know that programs that are built on one OS won't work on another, like a Windows program on a Linux distribution, and that there are programs that translate those system calls into system calls ...
3
votes
0answers
72 views
Evaluating concurrent application design approaches on Linux
Working on relatively low-speed hardware, I need to grab a snapshot of a rapidly changing datastream and then post-process the snapshot data and save it to disk.
I need help with designing the ...
1
vote
2answers
322 views
Strategy for creating a websocket relay?
I own a Raspberry Pi and would like to use it as some sort of websocket relay, so that all people who visit a specific webpage would be able to communicate with each other. The key thing about this is ...
28
votes
8answers
5k views
Why don't developers make installation wizards on linux? [closed]
I'm sure it's not about laziness or anything like that but I fail to understand why developers of even mainly consumer facing apps don't make any sort of installation wizard where you go ...
1
vote
2answers
685 views
Infinite while loop CPU usage
I'm coding an script in C, which is going to check constantly an array of events, the idea is to check if the Date and time of certain event is equal to de current time and trigger something, i'm ...
1
vote
2answers
319 views
Is creating and writing to one large file faster than creating and writing to many smaller files in Python on Linux?
If using Python on a Linux machine, which of the following would be faster? Why?
Creating a file at the very beginning of the program, writing very large amounts of data (text), closing it, then ...
0
votes
1answer
209 views
How to learn new technologies in short period of time? [duplicate]
The title says it all. I'm a .NET programmer, working mostly on WPF applications with C#. But I need to be familiar with latest web development technologies, JavaScript, HTML5, CSS, ASP.NET MVC, ...
3
votes
1answer
130 views
optimize human-readable database with index
i need to store a large amount of data - about 10 million entries of the format
unique hash (64 chars), value 1 (5 chars), value 2 (9 chars)
i will be reading and deleting (but not updating) this ...
-1
votes
3answers
537 views
Programming with emacs instead of a debugger-integrated IDE [closed]
There's a question that might be deemed a duplicate of this one (I use an IDE (Eclipse) to develop software. Why should I switch to vim or emacs?) but I don't think answers my question.
I usually ...
0
votes
1answer
199 views
What is the proper way to use an IDE to work on remote code?
One of the code bases I work on has a development environment that is running on a dev server and cannot be copied over to my PC to locally test and develop. I am wondering what is the proper way to ...
3
votes
2answers
331 views
What UML diagram should be used for modelling permissions/users/files in Linux?
If I am planning a structure for support testing in Linux, a structure that will contain packages, such files as shell and build scripts, app configurations, DBs, sources, tests and jars for to be ...
0
votes
1answer
140 views
Need advise for porting linux script to Win command line [closed]
I am creating app(script) that is used similar to RSS reader for specific webpage that doesn't have RSS.
So my app downloads that html page in defined intervals, checks new items and parses them into ...
1
vote
0answers
53 views
Auto Create VM and display IE
I have just acciquired an old Dell Poweredge SC1425 from an old friend, this server will act as a development box for web based applications. All has been going well, I have installed the following ...
2
votes
1answer
217 views
How to break up Yocto layers for continuous integration?
We are building embedded software using a Linux setup based on the Yocto project. We have a couple different configurations that we are building for different purposes (but the same target).
I have ...
2
votes
1answer
203 views
Moving our web application from a windows development environment to linux environment seamlessly
I am trying to develop a web application on a windows machine using apache wicket, java, jquery etc. Apache wicket comes with an embedded jetty server. I am using eclipse as the IDE.
The application ...
0
votes
1answer
340 views
Commercial use for embedded system
I am developing a embedded system (computer + os + programs) to sell it to a company.
I am confused about the licensing and the softwares I wanted to use to develop the system.So I want to know if I ...
0
votes
1answer
228 views
Scheduling between child and parent process
When child processes are created using the fork system call what is there scheduling priorities..are they same? if so will always a child process run first and then parent...or is there a manipulation ...
1
vote
1answer
115 views
Is it legal to distribute a closed source X Window Manager?
I’m doing a thought experiment about making a product on top of Linux. I’m wondering: If you make a custom window manager (akin to KDE, for example) on top of X and you release it, do you have to ...
3
votes
2answers
244 views
Tablet development for a dedicated system
I need to make an architectural decision for developing (actually porting) my embedded solution on a tablet.
The choice comes down to Ubuntu or Android, so I have some specific questions to help me ...
0
votes
1answer
618 views
Proxy to redirect DNS during development [closed]
I am using Genymotion to test an app. The app is basically a browser that connects to my website. I do not have the app's source.
I do the development and testing of the website in a domain like this: ...
1
vote
1answer
156 views
Python: Counter for Simultaneous calls of a PHP script?
I'm trying to create a queue processing script that's purpose is to find particular files and apply actions based on specific parameters,
with the result being to call a PHP script that serves to ...
