length buffer in the header and thus we must ensure it is not overrun. If
the user gives a source buffer that is too large, we truncate. The return
value is the number of bytes copied, or -1 for absolute failure (bad pointer
etc.). Errno is set:
EINVAL id poitner, buf or buf header are bad.
EOVERFLOW if the bytes given would have overrun
length buffer in the header and thus we must ensure it is not overrun. If
the user gives a source buffer that is too large, we truncate. The return
value is the number of bytes copied, or -1 for absolute failure (bad pointer
etc.). Errno is set:
EINVAL id poitner, buf or buf header are bad.
EOVERFLOW if the bytes given would have overrun