freebsd-skq/lib/libc/stdio/fread.3
Warner Losh fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00

106 lines
3.1 KiB
Groff

.\" Copyright (c) 1990, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Chris Torek and the American National Standards Committee X3,
.\" on Information Processing Systems.
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.\" modification, are permitted provided that the following conditions
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.\" @(#)fread.3 8.2 (Berkeley) 3/8/94
.\" $FreeBSD$
.\"
.Dd March 8, 1994
.Dt FREAD 3
.Os
.Sh NAME
.Nm fread ,
.Nm fwrite
.Nd binary stream input/output
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In stdio.h
.Ft size_t
.Fn fread "void * restrict ptr" "size_t size" "size_t nmemb" "FILE * restrict stream"
.Ft size_t
.Fn fwrite "const void * restrict ptr" "size_t size" "size_t nmemb" "FILE * restrict stream"
.Sh DESCRIPTION
The function
.Fn fread
reads
.Fa nmemb
objects, each
.Fa size
bytes long, from the stream pointed to by
.Fa stream ,
storing them at the location given by
.Fa ptr .
.Pp
The function
.Fn fwrite
writes
.Fa nmemb
objects, each
.Fa size
bytes long, to the stream pointed to by
.Fa stream ,
obtaining them from the location given by
.Fa ptr .
.Sh RETURN VALUES
The functions
.Fn fread
and
.Fn fwrite
advance the file position indicator for the stream
by the number of bytes read or written.
They return the number of objects read or written.
If an error occurs, or the end-of-file is reached,
the return value is a short object count (or zero).
.Pp
The function
.Fn fread
does not distinguish between end-of-file and error, and callers
must use
.Xr feof 3
and
.Xr ferror 3
to determine which occurred.
The function
.Fn fwrite
returns a value less than
.Fa nmemb
only if a write error has occurred.
.Sh SEE ALSO
.Xr read 2 ,
.Xr write 2
.Sh STANDARDS
The functions
.Fn fread
and
.Fn fwrite
conform to
.St -isoC .