( c-addr u -- )
If u is greater than zero, store the character value for
space in u consecutive character positions beginning at
c-addr.
Testing:
: s13 S" aaaaa a" ;\Six spacesT{ PAD 25 CHAR a FILL -> }T\Fill PAD with 25 'a's T{ PAD 5 CHARS+ 6 BLANK -> }T\Put 6 spaced from character 5 T{ PAD 12 s13 COMPARE -> 0 }T\PAD Should now be same as s13