diff options
Diffstat (limited to 'man-pages-posix-2003/man3p/fread.3p')
| -rw-r--r-- | man-pages-posix-2003/man3p/fread.3p | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/man-pages-posix-2003/man3p/fread.3p b/man-pages-posix-2003/man3p/fread.3p new file mode 100644 index 0000000..2b1ae6c --- /dev/null +++ b/man-pages-posix-2003/man3p/fread.3p @@ -0,0 +1,109 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "FREAD" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" fread +.SH PROLOG +This manual page is part of the POSIX Programmer's Manual. +The Linux implementation of this interface may differ (consult +the corresponding Linux manual page for details of Linux behavior), +or the interface may not be implemented on Linux. +.SH NAME +fread \- binary input +.SH SYNOPSIS +.LP +\fB#include <stdio.h> +.br +.sp +size_t fread(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 \fIfread\fP() function shall read into the array pointed to by +\fIptr\fP up to \fInitems\fP elements whose size is +specified by \fIsize\fP in bytes, from the stream pointed to by \fIstream\fP. +For each object, \fIsize\fP calls shall be made to +the \fIfgetc\fP() function and the results stored, in the order read, +in 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 read. If an error occurs, the resulting +value of the file position indicator for the stream is +unspecified. If a partial element is read, its value is unspecified. +.LP +The +\fIfread\fP() function may mark the \fIst_atime\fP field of the file +associated with \fIstream\fP for update. The +\fIst_atime\fP field shall be marked for update by the first successful +execution of \fIfgetc\fP(), \fIfgets\fP(), \fIfgetwc\fP(), \fIfgetws\fP(), +\fIfread\fP(), \fIfscanf\fP(), \fIgetc\fP(), \fIgetchar\fP(), \fIgets\fP(), +or \fIscanf\fP() using \fIstream\fP that returns data not supplied +by a prior call to \fIungetc\fP() or \fIungetwc\fP(). +.SH RETURN VALUE +.LP +Upon successful completion, \fIfread\fP() shall return the number +of elements successfully read which is less than +\fInitems\fP only if a read error or end-of-file is encountered. If +\fIsize\fP or \fInitems\fP is 0, \fIfread\fP() shall return +0 and the contents of the array and the state of the stream remain +unchanged. Otherwise, if a read 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 \fIfgetc\fP(). +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.SS Reading from a Stream +.LP +The following example reads a single element from the \fIfp\fP stream +into the array pointed to by \fIbuf\fP. +.sp +.RS +.nf + +\fB#include <stdio.h> +\&... +size_t bytes_read; +char buf[100]; +FILE *fp; +\&... +bytes_read = fread(buf, sizeof(buf), 1, fp); +\&... +\fP +.fi +.RE +.SH APPLICATION USAGE +.LP +The \fIferror\fP() or \fIfeof\fP() functions must +be used to distinguish between an error condition and an end-of-file +condition. +.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 +\fIfeof\fP(), \fIferror\fP(), \fIfgetc\fP(), \fIfopen\fP(), \fIgetc\fP(), +\fIgets\fP(), \fIscanf\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 . |