setlinebuf()

Assign line buffering to a stream

Synopsis:

#include <unix.h>

int setlinebuf( FILE *iop );

Library:

libc

Description:

The setbuffer() and setlinebuf() functions assign buffering to a stream. The types of buffering available are:

Unbuffered

Information appears on the destination file or terminal as soon as written.

Block buffered

Many characters are saved and written as a block.

Line buffered

Characters are saved until either a newline is encountered or input is read from stdin.

The fflush() function may be used to force the block out early. Normally all files are block buffered. A buffer is obtained from malloc() when the first getc() or putc() is performed on the file. If the standard stream stdout refers to a terminal, it's line buffered. The standard stream stderr is unbuffered by default.

The setlinebuf() function is used to change the buffering on a stream from block buffered or unbuffered to line buffered. Unlike setbuffer(), it can be used at any time that the stream iop is active.

A stream can be changed from unbuffered or line buffered to block buffered by using freopen(). A stream can be changed from block buffered or line buffered to unbuffered by using freopen() followed by setbuf() with a buffer argument of NULL.

Returns:

No useful value.

Classification:

Unix

See also:

fclose(), fflush(), fopen(), fread(), freopen(), getc(), malloc(), printf(), putc(), puts(), setbuf(), setbuffer(), setvbuf()