2.9BSD/usr/src/lib/libI77/rat_io.h

define(STDIN,	0)
define(STDOUT,	1)
define(STDERR,	2)
define(EOF,	char(-1))
define(NEWLINE,	'\\n')
define(TAB,	'\\t')
define(BACKSPACE,	'\\b')
define(BLANK,	' ')