Exercise "Hello, World!"

Install csharp-mono at your system and build a "Hello, World!" program" (a program that outputs "Hello, World!").

Tasks

Instal csharp mono on you system. On many systems it is prepackaged by system developers. For example, on Debian based systems you install mono with the command
```
sudo apt install mono-mcs
```
(there are also "mono-devel" and "mono-complete" packages, but it seems that "mono-mcs" is enough for us).
In Termux the command is
```
apt install mono
```
MacOS users might need to install mono from the mono-poject,
```
[https://www.mono-project.com/download/stable/#download-mac],
```
if the correponding Homebrew package isn't there (it seems like it's been deprecated).
Create a directory for the exercise inside your repository, let's say "~/repos/ppnm/exercises/hello",
```
mkdir -p ~/repos/ppnm/exercises/hello
```
Go to your directory (remember to use the completion feature of your shell !):
```
cd ~/repos/ppnm/exercises/hello
```

Create a Makefile with the following content (mind the tabulators!) (and you can omit the comments):

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 into hello.exe

clean:                           # a phoney target, no dependencies
	rm -f Out.txt hello.exe  # remove secondary files

Create a file hello.cs with the following content

class hello{
   static void Main(){
      System.Console.Write("hello\n");
   }
}

Run "make" and debug.
Make the progam output "Hello, your-user-name!" where "your-user-name" is your user name.

Hints

For nano users: you can indicate the invisible tabulator-signs with a color by adding the following lines to your "~/.nanorc" file,
```
syntax "makefile" "[Mm]akefile"
color white,magenta "	"
```
where the character in between the quotation marks in the second line should be the tabulator sign and where the colors are free for you to choose.

Alternatively, you can enable makefile syntax highlighting by adding the following line to your "~/.nanorc" file,

include /usr/share/nano/makefile.nanorc

If you use GNU make version 3.82+ and you don't like your recipies to start with the tabulator-sign, you can do
.RECIPEPREFIX := ;