test/unistd/truncate.out

st_size: 6

ftruncate(10): 0
errno: No error information
st_size: 10

ftruncate(4): 0
errno: No error information
st_size: 4

ftruncate(-1): -1
errno: Invalid argument
st_size: 4

truncate(2): 0
errno: No error information
st_size: 2

open(O_TRUNC)
errno: No error information
st_size: 0

truncate(readonly, 2): -1
errno: Permission denied
st_size: 6

ftruncate(readonly, 4): -1
errno: Invalid argument
st_size: 6

open(readonly, O_TRUNC)
errno: Permission denied
st_size: 6