SETBUF(3S) SETBUF(3S)
NAME
setbuf - assign buffering to a stream
SYNOPSIS
#include <stdio.h>
setbuf(stream, buf)
FILE *stream;
unsigned char *buf;
DESCRIPTION
Setbuf is used after a stream has been opened but before it
is read or written. It causes the character array buf to be
used instead of an automatically allocated buffer. If buf
is the constant pointer NULL, input/output will be com-
pletely unbuffered.
A manifest constant BUFSIZ tells how big an array is needed:
unsigned char buf[BUFSIZ];
A buffer is normally obtained from malloc(3) upon the first
getc or putc(3) on the file, except that the standard output
is line buffered when directed to a terminal. Other output
streams directed to terminals, and the standard error stream
stderr are normally not buffered. If the standard output is
line buffered, then it is flushed each time data is read
from the standard input by read(2).
SEE ALSO
fopen(3), getc(3), putc(3), malloc(3)