How init() works internally when used in C++ [closed] - c++

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Init() is the initial or we can say a daemon process being called up on Bootup runs till shutdown if we won't kill it. So, this a Linux based definition. I have doubt whether the same definition is applicable in C++ environment.
Help Appreciated.

There is a process named init on many1—but not all—Linux systems. It is the very first process launched by the kernel and is the parent or ancestor of all processes. init has PID 1.
This process has nothing to do with any function you might create named init(), in the same way that a function named bash() has no relation to the shell /bin/bash. Do not conflate process names with function names. One has no connection to the other.
1 I say many Linux systems because init has been replaced by systemd in most modern Linux distros. It looks like init will eventually become a historical relic.

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Killing a process with system C++ [closed]

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Is killing a process like system("taskkill /IM notepad.exe /F") good? Any other way?
There is no standard way to kill, or otherwise interact with processes in C++.
Note that using std::system with variable command is dangerous due to potential for shell injection, so be sure to use a constant command.
It is generally better to use a system library call instead of executing another process that does so. The API to use depend on the target system.
POSIX standard for example specifies the function kill that can be used to raise a signal to the target process. Raising the SIGETERM signal is a request for the process to terminate gracefully. SIGKILL will cause the operating system to terminate the process unconditionally.

How to detect and communicate with another process under Linux? [closed]

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I have a program 'P' and P is executed in terminal A. Let's call it process A. While process A is running, terminal B is opened and executes P as process B.
How can I make process A find process B and exchange data with each other? Someone told me to implement it with MPI but I haven't found any material telling me how.
I also appreciate that if anyone can tell me how to make these two process read and write the same variable (same address in memory). This solves my problem, too.
There are lots of options, but in most cases I think you'll find that named pipes/fifo will meet your needs.
See mkfifo, which creates a named pipe on the filesystem; that pipe can then be opened and accessed using standard open/read/write like a file for interprocess communications.

Launching another application through c++ code [closed]

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I would like to know if there is a way to launch an application through a c++ code? As if I was launching it through the command line (with giving parameters for example).
If it exists, please can you provide me with both the windows code as well as linux code (in case they differ).
You can use system calls, like:
exec()
fork()
You can find plenty of examples. I had also answered a question about fork() here.
For exec(), you could read this: Please explain exec() function and its family.
For Windows, you can use one of the spawn family of functions, like _wspawnl. For Linux, you can use one of the exec family of functions, in combination with fork, like execl.

UNIX c programming [closed]

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Can anybody tell me how you would do this question ?
Write short C program for a UNIX/Linux operating system that will do the following:
Fork a child process
The parent process prints out its own pid and its child’s pid
The parent exits properly so as not to orphan its child
The child process sets its own priority to 2
The child process prints out its own pid, its parent’s pid and its own priority
The child process checks if it is an orphan before finishing; if it is an orphan it prints a message to say “I am an orphan”.
You do not need to put any error checks in your program. You do not need to list all of the C library include files, i.e. the .h files.
Since stack overflow is by NO means a write code for me please website the only "answer" we can offer you is a suggestion on where to look. With that in mind look up pthreads. Beyond that I don't expect people to give you anything due dates are your problem not ours.

how to implement mount function in c/c++ [closed]

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I,m suppose to write a client/server program which mount a directory from the server into client hierarchy. What I have to do is, instead of using linux mount function, implement a method in c.c++ that works like mount function. I did a lot of googling on the net but can't find any good tutorial or document that could help. I will be very grateful if you help me and give me some advice, suggestion or introduce a tutorial/document as a starting point.
Your question is a bit vague. If this is an assignment, it could be about several things:
Implementing a filesystem (FUSE would probably be the simplest place to start).
Just emulating the calls, and defining your own e.g. ls, cd etc. for educational purposes, and bringing in the data from the server.
Implementing a tool like mount, possibly using the mount() system call.