problem with buffer in fread and fwite functions

[hamsha]

Hi everyone
I have some problem with fread and fwrite in VS2005 beta2
I have the following code, in it i generate a buffer and after assigning some values to it , i write it to a file , then i try to read it back to a new buffer which is not successful.
for variable bigVal=100 i get "k=100" for writing but for reading i get "k=77" , i would be pleased if someone can help me.

#include "stdafx.h"
#include <stdlib.h>
#include <time.h>
#include <stdio.h>

typedef double dtype;


int _tmain(int argc, _TCHAR* argv[])
{

dtype *b;
int i,j,k;
int bigVal;
char filename[]="c:\\temp.data";
FILE *fp;

bigVal=100;
b=(dtype*) malloc(bigVal * sizeof(dtype));

for(i=0 ; i<bigVal ; i++)
{
b=(i+1)/double(rand());
printf("b[%i]=%3.3g ",i,b);
}


if( (fp=fopen(filename,"w")) == NULL)
{
printf("Error in writing file %s \n",filename);
}
else
{
k=fwrite(b,sizeof(dtype),bigVal,fp);
printf("\n%i items wrote to file \n",k); // I get k=100 on my pc
fflush(fp);
fclose(fp);
}

free(b);

//tring to read the content of file
b=(dtype*) malloc(bigVal * sizeof(dtype));
if( (fp=fopen(filename,"r")) == NULL)
{
printf("Error in reading file %s \n",filename);
}
else
{
k=fread(b,sizeof(dtype),bigVal,fp);
printf("\n%i items read from file \n",k);// I get k=77 on my pc
fclose(fp);
}
for(i=0 ; i<bigVal ; i++)
{
printf("b[%i]=%3.3g ",i,b);
// here on my pc from start to b[76] are ok but b[77] to end are Not ok
}

free(b);
return 0;
}

 

[Salem]

> b=(dtype*) malloc(bigVal * sizeof(dtype));
Are you intending this to be a C or C++ program?
If it's C, then there's no need to cast malloc.
If it's C++, then you should be using new/delete for memory allocation.

> if( (fp=fopen(filename,"r")) == NULL)
Try it with "rb" and "wb" when opening the file.

Please remember to use [code][/code] tags when posting code.

--

 

[mihk]

the code is good, remove fflush(fp);
mihk