Great, thanks, I'll look for ncurses then

hi is it possible to use a file pointer name in a function in another c file where it is not declared?

Hello

There is, but this group is not for this :)

What??

banhammer incomin'

Easy*

can anyone name an example of variable declaration

can anyone name an example of variable declaration

int i;

int i;

Next

I need 5 example

You do the other 4, it's not hard, use other types too

You do the other 4, it's not hard, use other types too

is it like this for example int integer;

Yes

Or #include <iostream> using namespace std; int main() { int myNum = 15; cout << myNum; return 0; }

what about variable initialization

if you need to learn faster, then you need to practice....more and more...you do it every hours everyday

if you need to learn faster, then you need to practice....more and more...you do it every hours everyday

Brother how to learn fast any programming concept

Brother how to learn fast any programming concept

when i learn something new like malbolge programming that i've learn, i take all of my time to practice and practice. i never stop until i can do it by my self. Theory can not help you if you are not do it. Practice can help you to be faster when you learn something new. Theory then practice, theory and practice.

Hello guys, I need some help with converting a private chat based on tcp to udp

I have some problems with multithread

I have some problems with multithread

Like what problem?

I can manage one single client

But I have some issues with managing multiple clients

can I share my github so that someone could see the issue?

can I share my github so that someone could see the issue?

Sure...

Any programing platform which is easier than visual studio??

I can’t share my GitHub link

can I share my github so that someone could see the issue?

@includej: https://github.com/includej/SoProject There are two folders. One for a private chat written in Tcp and another one for UDP. tcp private chat works perfectly Udp works just with one client.

@includej: https://github.com/includej/SoProject There are two folders. One for a private chat written in Tcp and another one for UDP. tcp private chat works perfectly Udp works just with one client.

thanks

Do I really need to initialize the array before the Macro? https://imgur.com/a/DhwmEGV

Hi, is there a way to spawn a new terminal command line on Linux from C? I'm working on Ubuntu, but I would need this method to work for every linux distro. This new window should appear when a certain signal is handled, the user does stuff, then should disappear. Can you direct me to some documentation or maybe a video, or anything, to both create and close the terminal window? Thanks!

You can just execute new terminal that is not a problem... closing the new terminal window might be harder depending on how you want to do it... Probably you could remember the forked PID and then sigterm it

How can I invoke destructors for an array that I constructed in-memory using placement new? void* data = allocateSomehow(); SomeType* myArr = new (data) SomeType[count]; ... myArr ->~ ??? // how can I destroy freeSomehow(data);

For the record, what I want it for, I want to allocate memory for two arrays of different types in one allocation (sizes not known at compile time).

Hey

How can I take user input input in pair in 2d vector in c++

Please help me

You can just execute new terminal that is not a problem... closing the new terminal window might be harder depending on how you want to do it... Probably you could remember the forked PID and then sigterm it

mmm the forked PID is a good idea actually, but I need the software to spawn it on its own. All in all, I set an alarm(240), which causes the software to be hit by the SIGALARM signal after 4 minutes. When this happens, the handler takes place. Since the former terminal window is already filled with some information that we can't delete, and the user needs to write stuff on the socket, I need the software to autospawn a window

mmm the forked PID is a good idea actually, but I need the software to spawn it on its own. All in all, I set an alarm(240), which causes the software to be hit by the SIGALARM signal after 4 minutes. When this happens, the handler takes place. Since the former terminal window is already filled with some information that we can't delete, and the user needs to write stuff on the socket, I need the software to autospawn a window

alarm won't work if you run multiple of them...

and idk how it is on windows exactly with PIDs and stuff (I quite lack the knowledge of win interface)

How can I take user input input in pair in 2d vector in c++

ask for 2 inputs, std::Make_pair and push (or maybe emplace)

How can I invoke destructors for an array that I constructed in-memory using placement new? void* data = allocateSomehow(); SomeType* myArr = new (data) SomeType[count]; ... myArr ->~ ??? // how can I destroy freeSomehow(data);

delete myArr

mmm then I could try a setsockopt to give control back to the process after 4 minutes

delete myArr

although this is not recommended afaik

delete myArr

(or maybe actually delete[] myArr... not sure)

mmm then I could try a setsockopt to give control back to the process after 4 minutes

or you could have the alarm and check how long the terminals were running

or you could have the alarm and check how long the terminals were running

I wouldn't know how to do it, but the PID thing you told me earlier will surely be useful

I wouldn't know how to do it, but the PID thing you told me earlier will surely be useful

well you could have in the main thread list of all spawned processes and you could remember like the timestamp when you have spawned them... or you could try some async lib (although that is probably overkill)

delete myArr

delete also deallocates the memory (also by specific rules, it's not said how I get the memory)

Any programing platform which is easier than visual studio??

How can I invoke destructors for an array that I constructed in-memory using placement new? void* data = allocateSomehow(); SomeType* myArr = new (data) SomeType[count]; ... myArr ->~ ??? // how can I destroy freeSomehow(data);

OK, so in the end I do this: void* data = allocateSomehow(); SomeType* keysAlias = reinterpret_cast<SomeType*>(data); for (size_t i = 0; i < count; ++i) { new (keysAlias + i) SomeType(); } ... for (size_t i = 0; i < count; ++i) { (keysAlias + i)->~SomeType(); } freeSomehow(data); A lot of code, but at least generates no assembly for basic types

Fuk, sorry wrong typeing

Touch error

sure

Fuk, sorry wrong typeing

hehe, alright, i pardoned it

hehe, alright, i pardoned it

lol so you wanna say you believe this? so naive klimi, so naive

How can I invoke destructors for an array that I constructed in-memory using placement new? void* data = allocateSomehow(); SomeType* myArr = new (data) SomeType[count]; ... myArr ->~ ??? // how can I destroy freeSomehow(data);

You have to run the destructors for the individual elements of the array manually in the reverse order of construction. If your array is of type SomeType and the length of the array is len, thenyou have to do this: for(auto i = len - 1; i>= 0; i--){ data[i].~SomeType(); } freeSomeHow(data);

lol so you wanna say you believe this? so naive klimi, so naive

Yep

You have to run the destructors for the individual elements of the array manually in the reverse order of construction. If your array is of type SomeType and the length of the array is len, thenyou have to do this: for(auto i = len - 1; i>= 0; i--){ data[i].~SomeType(); } freeSomeHow(data);

But shouldn't I then construct them manually in a loop also (like in my last message?)

How can I invoke destructors for an array that I constructed in-memory using placement new? void* data = allocateSomehow(); SomeType* myArr = new (data) SomeType[count]; ... myArr ->~ ??? // how can I destroy freeSomehow(data);

No. Placement new constructs the elements in the memory you give to it. The default constructors would have run. Your job is to run the destructors. There is no equivalent to placement new for destruction of elements. You have to do it manually like I suggested above.

You have to run the destructors for the individual elements of the array manually in the reverse order of construction. If your array is of type SomeType and the length of the array is len, thenyou have to do this: for(auto i = len - 1; i>= 0; i--){ data[i].~SomeType(); } freeSomeHow(data);

Why the order need to be reverse by the way, does it matter in which order they will be destroyed?

No. Placement new constructs the elements in the memory you give to it. The default constructors would have run. Your job is to run the destructors. There is no equivalent to placement new for destruction of elements. You have to do it manually like I suggested above.

Yes, but won't it be more consistent if placement new will be also called per-object if we destroy them per object? Otherwise feels strange that we construct an array but destroy individual objects.

Why the order need to be reverse by the way, does it matter in which order they will be destroyed?

The usual standard way is for elements to be destructed in the reverse order of construction. It makes sense if you think that the element created last may depend on elements created before it. So destroying it first makes sense. All the STL containers follow that principle as well. It may not matter in your case but if you are designing a library, a user may use your library to create objects with dependencies. So destroying in the same order you created them may violate invariants of the User Defined Type and may lead to Undefined Behavior.

Yes, but won't it be more consistent if placement new will be also called per-object if we destroy them per object? Otherwise feels strange that we construct an array but destroy individual objects.

You shouldn't be using placement new then to construct the whole array. Create individual elements in the memory allocated as they would be laid out if in an array. Placement new just makes your job a lot easier.

Another question, is this a right way of having two arrays of different types in the same piece of memory? https://wandbox.org/permlink/sUikkwSKXSmsEPYr

I wonder if I introduced some UB or this looks fine UPD: nevermind, found that I'm doing something stupid with the alignment

I wonder if I introduced some UB or this looks fine UPD: nevermind, found that I'm doing something stupid with the alignment

Your gapSize calculation is wrong.

Your gapSize calculation is wrong.

Yes just saw it also, I don't know what I was thinking about 😓

how can i print the result of a^b in (c) with out using a loop?

how can i print the result of a^b in (c) with out using a loop?

you just print it

how can i print the result of a^b in (c) with out using a loop?

cout<<a*b; printf("%d",a*b);

Do I really need to initialize the array before the Macro? https://imgur.com/a/DhwmEGV

Why private member functions are declared in c++?

Why private member functions are declared in c++?

so that it is only used within the class itself and it's members.

Why private member functions are declared in c++?

I believe to be able to "hide" from user to avoid undesirable use of those functions. Like indexing which allows you both read and change the data but you want only user to be able to read it. In that case, you can make it private and implement read_by_index(int idx) {return a[idx]}

Probably bad example. Probably someone can give a better one

Why private member functions are declared in c++?

Because they are mostly implementation details and are not required to be part of the interface of the class. Because they can easily be changed without affecting the users of the class. Because they offer some common functionality that can be shared by other public member functions and hence not required to maintain invariants of the class. They hence can't be directly called by users.

Maybe something like a Movie class where you can use a public method searchMovie(std::string) to search for a movie by sending request to a rest API hosted somewhere. First you will check what kind of response i.e status code you get for the request. You can create that method int returnStatusCode (); in private because it will be only used within the searchMovie() method and you don't want it to be accessible on the outside.

How to convert a string input to raw string in cpp?