NAME

setbuf - assign buffering to a stream

SYNOPSIS

#include <stdio.h>

void setbuf(FILE *restrict stream, char *restrict buf);


DESCRIPTION

^[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.

Except that it returns no value, the function call:

setbuf(stream, buf)

shall be equivalent to:

setvbuf(stream, buf, _IOFBF, BUFSIZ)

if buf is not a null pointer, or to:

setvbuf(stream, buf, _IONBF, BUFSIZ)

if buf is a null pointer.

RETURN VALUE

The setbuf() function shall not return a value.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

A common source of error is allocating buffer space as an "automatic" variable in a code block, and then failing to close the stream in the same block.

With setbuf(), allocating a buffer of BUFSIZ bytes does not necessarily imply that all of BUFSIZ bytes are used for the buffer area.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

fopen , setvbuf

XBD <stdio.h>

CHANGE HISTORY

First released in Issue 1. Derived from Issue 1 of the SVID.

Issue 6

The prototype for setbuf() is updated for alignment with the ISO/IEC 9899:1999 standard.