using System;
using System.IO;
using System.Runtime.InteropServices;

namespace Cyberpipe
{
    class FileStatus
    {
        [DllImport("kernel32.dll")]
        private static extern IntPtr _lopen(string lpPathName, int iReadWrite);
        [DllImport("kernel32.dll")]
        private static extern bool CloseHandle(IntPtr hObject);
        private const int OF_READWRITE = 2;
        private const int OF_SHARE_DENY_NONE = 0x40;
        private static readonly IntPtr HFILE_ERROR = new IntPtr(-1);
        public static int FileIsOpen(string fileFullName)
        {
            if (!File.Exists(fileFullName))
            {
                return -1;
            }

            IntPtr handle = _lopen(fileFullName, OF_READWRITE | OF_SHARE_DENY_NONE);
            if (handle == HFILE_ERROR)
            {
                return 1;
            }
            CloseHandle(handle);
            return 0;
        }
    }
}