_IOLBF macro — Line buffering
int _IOLBF
When passed as the mode
parameter to setvbuf
, the
_IOLBF
macro sets an open file to
line buffering. A buffer is flushed when it is full or when a
newline character is read or written. The _IOLBF
macro expands to a constant
integer.
Support for line-buffered streams is implementation-dependent.