: cbuf buf bsize 0 FILL ;
: fn2 S" fatest2.txt" ;
VARIABLE fid2
: setpad PAD 50 0 DO I OVER C! CHAR+ LOOP DROP ;

setpad

Note: If anything else is defined setpad must be called again as the pad may move

T{ fn2 R/W BIN CREATE-FILE SWAP fid2 ! -> 0 }T
T{ PAD 50 fid2 @ WRITE-FILE fid2 @ FLUSH-FILE -> 0 0 }T
T{ fid2 @ FILE-SIZE -> 50. 0 }T
T{ 0. fid2 @ REPOSITION-FILE -> 0 }T
T{ cbuf buf 29 fid2 @ READ-FILE -> 29 0 }T
T{ PAD 29 buf 29 COMPARE -> 0 }T
T{ PAD 30 buf 30 COMPARE -> 1 }T
T{ cbuf buf 29 fid2 @ READ-FILE -> 21 0 }T
T{ PAD 29 + 21 buf 21 COMPARE -> 0 }T
T{ fid2 @ FILE-SIZE DROP fid2 @ FILE-POSITION DROP D= -> <TRUE> }T
T{ buf 10 fid2 @ READ-FILE -> 0 0 }T
T{ fid2 @ CLOSE-FILE -> 0 }T