How to close a port without iptables on Linux?

Question

Angular

Good evening!
Tell me how to completely close one port (namely 443) in Linux without using iptables?

Answer 1

my.service.ts

@Injectable({
    providedIn: 'root',
 })
 export class MyService {
  public myVar$ = new Subject();
 }

comp1.component.html comp1.component.ts

export class Comp1Component {
  constructor(
    public myService: MyService
  ) {}
}

comp2.component.ts

export class Comp2Component {
  constructor(
    public myService: MyService
  ) {}
  myFunc(){
  this.myService.myVar$.next(1000);
  }
  
}

when you do next to a subject, all callbacks of subscribers of this subject are called. Including AsyncPipe in the comp1 component. AsyncPipe starts the change detector and outputs the value of the observable myService.myVar$ to the template (any subject is an observable)

Answer 2

in short, you need to sit and read about RxJS - https://rxjs-dev.firebaseapp.com/
otherwise you will go so long
with myVar having an Observable type
and then you overwrite it and enter 1000 (number)
according to the correct one: myVar.next (1000)

Answer 3

stop service running on port 443