mirror of https://github.com/mkerrisk/man-pages
81 lines
2.9 KiB
Plaintext
81 lines
2.9 KiB
Plaintext
.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
|
|
.TH "FWRITE" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
|
|
.\" fwrite
|
|
.SH NAME
|
|
fwrite \- binary output
|
|
.SH SYNOPSIS
|
|
.LP
|
|
\fB#include <stdio.h>
|
|
.br
|
|
.sp
|
|
size_t fwrite(const void *restrict\fP \fIptr\fP\fB, size_t\fP \fIsize\fP\fB,
|
|
size_t\fP \fInitems\fP\fB,
|
|
.br
|
|
\ \ \ \ \ \ FILE *restrict\fP \fIstream\fP\fB);
|
|
.br
|
|
\fP
|
|
.SH DESCRIPTION
|
|
.LP
|
|
The \fIfwrite\fP() function shall write, from the array pointed to
|
|
by \fIptr\fP, up to \fInitems\fP elements whose size is
|
|
specified by \fIsize\fP, to the stream pointed to by \fIstream\fP.
|
|
For each object, \fIsize\fP calls shall be made to the \fIfputc\fP()
|
|
function, taking the values (in order) from an array of \fBunsigned
|
|
char\fP
|
|
exactly overlaying the object. The file-position indicator for the
|
|
stream (if defined) shall be 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.
|
|
.LP
|
|
The
|
|
\fIst_ctime\fP and \fIst_mtime\fP fields of the file shall be marked
|
|
for update between the successful execution of
|
|
\fIfwrite\fP() and the next successful completion of a call to \fIfflush\fP()
|
|
or \fIfclose\fP() on the same stream, or a call to \fIexit\fP()
|
|
or \fIabort\fP().
|
|
.SH RETURN VALUE
|
|
.LP
|
|
The \fIfwrite\fP() function shall return the number of elements successfully
|
|
written, which may be less than \fInitems\fP if a
|
|
write error is encountered. If \fIsize\fP or \fInitems\fP is 0, \fIfwrite\fP()
|
|
shall return 0 and the state of the stream
|
|
remains unchanged. Otherwise, if a write error occurs, the error indicator
|
|
for the stream shall be set, \ and
|
|
\fIerrno\fP shall be set to indicate the error.
|
|
.SH ERRORS
|
|
.LP
|
|
Refer to \fIfputc\fP() .
|
|
.LP
|
|
\fIThe following sections are informative.\fP
|
|
.SH EXAMPLES
|
|
.LP
|
|
None.
|
|
.SH APPLICATION USAGE
|
|
.LP
|
|
Because of possible differences in element length and byte ordering,
|
|
files written using \fIfwrite\fP() are
|
|
application-dependent, and possibly cannot be read using \fIfread\fP()
|
|
by a different
|
|
application or by the same application on a different processor.
|
|
.SH RATIONALE
|
|
.LP
|
|
None.
|
|
.SH FUTURE DIRECTIONS
|
|
.LP
|
|
None.
|
|
.SH SEE ALSO
|
|
.LP
|
|
\fIferror\fP() , \fIfopen\fP() , \fIprintf\fP()
|
|
, \fIputc\fP() , \fIputs\fP() , \fIwrite\fP() , the
|
|
Base Definitions volume of IEEE\ Std\ 1003.1-2001, \fI<stdio.h>\fP
|
|
.SH COPYRIGHT
|
|
Portions of this text are reprinted and reproduced in electronic form
|
|
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
|
|
-- Portable Operating System Interface (POSIX), The Open Group Base
|
|
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
|
|
Electrical and Electronics Engineers, Inc and The Open Group. 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 Standard
|
|
is the referee document. The original Standard can be obtained online at
|
|
http://www.opengroup.org/unix/online.html .
|