1	program trutst
2	integer ftell
3	external ftell
4
5	rewind 1
6	write(1,*) "This is line A."
7	write(1,*) "This is line B."
8	write(1,*) "This is line C."
9	write(1,*) "This is line D."
10	backspace 1
11	endfile 1
12	call system ("cat fort.1")
13	write(*,*) "---"
14	rewind 1
15	write(1,*) "This is line E."
16	write(1,*) "This is line F."
17	close(1)
18	call system ("cat fort.1")
19	end
20