Any Fortran program has to include
end as last statement. Therefore, the simplest Fortran program looks like this:
Here are some examples of "hello, world" programs:
print *, "Hello, world" end
write(*,*) "Hello, world" end
For clarity it is now common to use the
program statement to start a program and give it a name. The
end statement can then refer to this name to make it obvious what it is referring to, and let the compiler check the code for correctness. Further, all Fortran programs should include an
implicit none statement. Thus, a minimal Fortran program actually should look as follows:
program hello implicit none write(*,*) 'Hello world!' end program hello
The next logical step from this point is how to see the result of the hello world program. This section shows how to achieve that in a linux like environment. We assume that you have some basic notions of shell commands, mainly you know how to get to the shell terminal. We also assume that you have already setup your
fortran environment. Using your preferred text editor (notepad, notepad++, vi, vim, emacs, gedit, kate, etc.), save the hello program above (copy and paste) in a file named
hello.f90 in your home directory.
hello.f90 is your source file. Then go to the command line and navigate to the directory(home directory?) where you saved your source file, then type the following command:
>gfortran -o hello hello.f90
You just created your hello world executable program. In technical terms, you just compiled your program. To run it, type the following command:
You should see the following line printed on your shell terminal.
> Hello world!
Congratulations, you just wrote, compiled and ran the "Hello World" program.