FREAD(3) Linux Programmer's Manual FREAD(3)NAME
fread, fwrite - binary stream input/output
SYNOPSIS
#include <stdio.h>
size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream);
size_t fwrite(const void *ptr, size_t size, size_t nmemb,
FILE *stream);
DESCRIPTION
The function fread() reads nmemb elements of data, each size bytes long, from the stream pointed to by stream, storing them at the location
given by ptr.
The function fwrite() writes nmemb elements of data, each size bytes long, to the stream pointed to by stream, obtaining them from the
location given by ptr.
For nonlocking counterparts, see unlocked_stdio(3).
RETURN VALUE
fread() and fwrite() return the number of items successfully read or written (i.e., not the number of characters). If an error occurs, or
the end-of-file is reached, the return value is a short item count (or zero).
fread() does not distinguish between end-of-file and error, and callers must use feof(3) and ferror(3) to determine which occurred.
CONFORMING TO
C89, POSIX.1-2001.
SEE ALSO read(2), write(2), feof(3), ferror(3), unlocked_stdio(3)COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 1996-05-17 FREAD(3)
Check Out this Related Man Page
FREAD(3) Linux Programmer's Manual FREAD(3)NAME
fread, fwrite - binary stream input/output
SYNOPSIS
#include <stdio.h>
size_t fread(void *ptr, size_t size, size_t nmemb, FILE *stream);
size_t fwrite(const void *ptr, size_t size, size_t nmemb,
FILE *stream);
DESCRIPTION
The function fread() reads nmemb elements of data, each size bytes long, from the stream pointed to by stream, storing them at the location
given by ptr.
The function fwrite() writes nmemb elements of data, each size bytes long, to the stream pointed to by stream, obtaining them from the
location given by ptr.
For nonlocking counterparts, see unlocked_stdio(3).
RETURN VALUE
On success, fread() and fwrite() return the number of items read or written. This number equals the number of bytes transferred only when
size is 1. If an error occurs, or the end of the file is reached, the return value is a short item count (or zero).
fread() does not distinguish between end-of-file and error, and callers must use feof(3) and ferror(3) to determine which occurred.
CONFORMING TO
C89, POSIX.1-2001.
SEE ALSO read(2), write(2), feof(3), ferror(3), unlocked_stdio(3)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
GNU 2012-03-30 FREAD(3)
After my previous thread, I think I found out what causes the long delays.
I run this program on several Linux computers, and the sometimes (after the file with the arrays becomes big) the fwrite takes between 100 ms to 900 ms.
This is very bad for me, as I want a timer to halt each 30 ms.... ... (5 Replies)
Hi ,
I am running a C/C++ program on a solaris 5.8 machine. This parituclar application has a module which saves data to a file. The module uses fwrite() function to save data.
The fwrite function write about 500 MB of data to a file. The problem which I am facing is, the memory consumtion... (2 Replies)
I use a standard C source to access large files in a 32 bit environment.
I've replaced fopen, fwrite and fread by fopen64, fwrite64 and fread64.
First I did a test only replacing fopen by fopen64, it compiled without any other changes to my compilation options.
The program crashed on a write, as... (3 Replies)
Hi
I have an fwrite function in my C++ application. It is able to create the files in HP-UX.
cross is one structure
rec2 is another structure within cross.
fwrite_return = fwrite( &cross.rec2,
sizeof(cross.rec2),
... (14 Replies)
Hi,
my code is written in proC and it is in UNIX(AIX).I have written a small code for writing data into a binary file,but while writing my program is giving core dump.
Here Is my code----
fpWriteFile = fopen(WriteFileName,"wb+");
CHAR *recvgen;
recvgen = (char... (7 Replies)
hi guys.
can we use fread and fwrite with pipes to write data more than PIPE_BUF atomically since they lock FILE object until I/O operation finish? (1 Reply)
Hello,
I have a question about what happens when I copy the file which is being written by another process on Solaris 9/SPARC, UFS file system.
in particular, I want to know what happens while some process is reading the file using fread or mmap, another process try to write something on the... (4 Replies)
The fwrite function call is not returning error, when the file it writes to is removed, please advise on how to find if the file already opened and being written by a program is removed manually or by some other process.
please see the code below,
#include<stdio.h>
#include<stdlib.h>
... (3 Replies)
Hello,
I am trying to read a text file into linked list, but always got the first and last records wrong.
1) The problem looks related to the initialization of the node temp with malloc(), but could not figure it out. No error/warning at compiling, though.
2) The output file is empty,... (10 Replies)
I have some matlab code that sends the serial port elements of an array using matlab's fwrite function, e.g.:
fwrite(s, , 'uchar');
What would be a unix shell equivalent? E.g., after successfully accessing the port using instructions here:
Simple terminal serial port program for Linux/MacOSX... (3 Replies)