[schoen]

Strictly speaking, as discussed elsewhere in this thread, ^D can cause a terminal device to signal an EOF condition; other kinds of Unix byte streams don't make this association.

For example,

  $ python3 -c 'print("".join(chr(c) for c in range(10)))' | python3 -c 'print(list(ord(c) for c in input()))'

will confirm that it doesn't happen in a pipe (the ASCII 4 character there is totally unrelated to EOF).