shared_file_access

shared_file.cpp

// shared_file.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <Windows.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/locking.h>
#include <share.h>
#include <fcntl.h>
#include <cstdio>
#include <cstdlib>
#include <io.h>
#include <safeint.h>
#include <cstdint>

namespace 
{

char buffer[] = "This is a test of '_write' function\n";

}

int _tmain(int argc, _TCHAR* argv[])
{
    int file;
    unsigned    bytesWritten = 0;
    const auto err = _sopen_s(&file, "d:\\work\\shared.txt", _O_WRONLY | _O_CREAT | _O_APPEND, _SH_DENYNO, _S_IREAD | _S_IWRITE);
    
    printf("%d %d\n", err, file);
    if (err != 0)
        exit(1);

    for (int i = 1; i < 1000000; ++i)
    {
        if ((bytesWritten = _write(file, buffer, sizeof(buffer) - 1)) == -1)
        {
            printf_s("Unexpected error %d\n", errno);
            break;
        }
        else
        {
            printf_s("Wrote %u bytes to file.\n", bytesWritten);
            ::Sleep(50);
        }
    }
    _close(file);

	return 0;
}