posix man page for setbuf

SETBUF(3P)						     POSIX Programmer's Manual							SETBUF(3P)

PROLOG
       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME
       setbuf -- assign buffering to a stream

SYNOPSIS
       #include <stdio.h>

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

DESCRIPTION
       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
       Although the setvbuf() interface may set errno in defined ways, the value of errno after a call to setbuf() is unspecified.

       The following sections are informative.

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.

       Since errno is not required to be unchanged on success, in order to correctly detect and possibly recover from errors, applications  should
       use setvbuf() instead of setbuf().

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       Section 2.5, Standard I/O Streams, fopen(), setvbuf()

       The Base Definitions volume of POSIX.1-2008, <stdio.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C)  2013  by	the  Institute	of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Stan-
       dard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE
/The Open Group						       2013								SETBUF(3P)