How to reverse a chain of characters?

Question

I have to create a program that reverses phrases.

For example: when I write hello guys, I want syug olleh

This is what

Answer 1

@Rook's answer works for odd length of string too? Anyway here's my attempt, inspired by his answer which takes into account trailing blanks too:

    ! Reverse the string
    function reverse_string(string) result(gnirts)

        character(len=*) :: string
        character(len(string)) :: gnirts
        character(1) :: temp
        integer :: i, length

        length = len(string) 

        do i = 1,length
            gnirts(length-i+1:length-i+1) = string(i:i)
        end do

end function reverse_string