← ppnm

Exercise "Hello, World!"

Tasks

  1. Install the programming language of your choice on your system.

  2. Create a directory for the exercise inside your repository, let's say "~/repos/ppnm/exercises/hello", 

    mkdir -p ~/repos/ppnm/exercises/hello

  3. Go to your directory (remember to use the completion feature of your shell !): 

    cd ~/repos/ppnm/exercises/hello
  4. Create a Makefile with the following content (mind the tabulators!) (and you can omit the comments).
    • Makefile for Csharp: 
    Out.txt : hello.exe              # Out.txt depends on hello.exe
	mono hello.exe > Out.txt # run hello.exe, send output to Out.txt

hello.exe : hello.cs             # hello.exe depends on hello.cs
	mcs hello.cs             # compile hello.cs, save bytecode in hello.exe

clean:                           # a phoney target, no dependencies
	rm -f Out.txt hello.exe  # remove secondary files
    • Makefile for C++: 
    Out.txt : hello.exe             # Out.txt depends on hello.exe
	./hello.exe > Out.txt        # run hello.exe, send output to Out.txt
hello.exe: hello.cc                 # hello depends on hello.cc
	clang++ -o hello.exe hello.cc  # compile-and-link hello.cc, save executable in hello.exe
clean:
	rm -f Out.txt hello.exe
  5. Create a file hello.cs (hello.cc) with the following content,
    • hello.cs: 
    class hello{
static int Main(){
	System.Console.Write("hello\n");
	return 0;
	}
}
    • hello.cc: 
    #include<iostream> /* std::cout */
#include<stdio.h>  /* printf */
int main(){
	std::cout << "Hello, ";
	printf("World!\n");
	return 0;
}
  6. Run "make" and debug.
  7. Make the progam output "Hello, your-user-name!" where "your-user-name" is your user name.

Hints