setbuf \- assign buffering to a stream
is used after a stream has been opened but before it
It causes the character array
to be used instead of an automatically allocated buffer.
input/output will be completely unbuffered.
tells how big an array is needed:
A buffer is normally obtained from
except that output streams directed to terminals,
and the standard error stream
are normally not buffered.
fopen(3), getc(3), putc(3), malloc(3)