xref: /titanic_51/usr/src/man/man3c/fwrite.3c (revision 45e662eb8429b38c18931ebeed30f2e5287ae51b)
te
Copyright (c) 1997, The Open Group. All Rights Reserved.
Copyright 1989 AT&T
Portions Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved.
Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
FWRITE 3C "Jul 24, 2002"
NAME
fwrite - binary output
SYNOPSIS

#include <stdio.h>

size_t fwrite(const void *ptr, size_t size, size_t nitems, FILE *stream);
DESCRIPTION

The fwrite() function writes, from the array pointed to by ptr, up to nitems elements whose size is specified by size, to the stream pointed to by stream. For each object, size calls are made to the fputc(3C) function, taking the values (in order) from an array of unsigned char exactly overlaying the object. The file-position indicator for the stream (if defined) is advanced by the number of bytes successfully written. If an error occurs, the resulting value of the file-position indicator for the stream is unspecified.

The st_ctime and st_mtime fields of the file will be marked for update between the successful execution of fwrite() and the next successful completion of a call to fflush(3C) or fclose(3C) on the same stream or a call to exit(2) or abort(3C).

RETURN VALUES

The fwrite() function returns the number of elements successfully written, which might be less than nitems if a write error is encountered. If size or nitems is 0, fwrite() returns 0 and the state of the stream remains unchanged. Otherwise, if a write error occurs, the error indicator for the stream is set and errno is set to indicate the error.

ERRORS

Refer to fputc(3C).

USAGE

Because of possible differences in element length and byte ordering, files written using fwrite() are application-dependent, and possibly cannot be read using fread(3C) by a different application or by the same application on a different processor.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Standard
MT-Level MT-Safe
SEE ALSO

write(2), fclose(3C), ferror(3C), fopen(3C), fread(3C), getc(3C), gets(3C), printf(3C), putc(3C), puts(3C), attributes(5), standards(5)