module vt100
	character, parameter :: EFFECT_NORMAL    = "0"
	character, parameter :: EFFECT_BOLD      = "1"
	character, parameter :: EFFECT_ITALIC    = "3"
	character, parameter :: EFFECT_UNDERLINE = "4"
	character, parameter :: EFFECT_BLINK     = "5"
	character, parameter :: EFFECT_REVERSE   = "7"
	character, parameter :: COLOUR_GREY      = "0"
	character, parameter :: COLOUR_RED       = "1"
	character, parameter :: COLOUR_GREEN     = "2"
	character, parameter :: COLOUR_YELLOW    = "3"
	character, parameter :: COLOUR_BLUE      = "4"
	character, parameter :: COLOUR_PINK      = "5"
	character, parameter :: COLOUR_CYAN      = "6"
	character, parameter :: COLOUR_WHITE     = "7"
end module vt100

program xscii
	use vt100

	implicit none

	interface
		subroutine print_colour (colour, effect)
			character, intent (in) :: colour
			character, intent (in) :: effect
		end subroutine print_colour

		subroutine print_cancel
		end subroutine print_cancel

		subroutine print_bar
		end subroutine print_bar
	end interface

	integer :: i

	call print_colour (COLOUR_BLUE, EFFECT_BOLD)
	write (*, '(a)', advance='no') "Heyo!"
	call print_cancel
	print *

	call print_bar
	print *

	do i = 1, 10
		print *, "> ", i
	end do

end program xscii

subroutine print_colour (colour, effect)
	use vt100

	implicit none

	character, intent (in) :: colour
	character, intent (in) :: effect
	character (7)          :: escape

	escape = char (27) // "[" // effect // ";3" // colour // "m"

	write (*, '(a)', advance='no') escape
end subroutine print_colour

subroutine print_cancel
	use vt100

	implicit none

	character (4) :: escape

	escape = char (27) // "[0m"

	write (*, '(a)', advance='no') escape
end subroutine print_cancel

subroutine print_bar
	use vt100

	implicit none

	call print_colour (COLOUR_GREY, EFFECT_BOLD)
	write (*, '(a)', advance='no') " | "
	call print_cancel
end subroutine print_bar