I have this function for validate a file copy : it an important function of backup so i have to be sure both file are exactly the same (not implemented security and atribut yet).
Here it is:
public class fileCheck
{
public bool sourceExist { get; set; }
public bool DestExist { get; set; }
public bool bothSizeMatch { get; set; }
public bool bothDateMatch { get; set; }
public bool bothAclMatch { get; set; }
}
public fileCheck fileAlreadyExist(string source, string dest)
{
fileCheck f = new fileCheck();
if (File.Exists(source))
{
f.sourceExist = true;
}
else
{
f.sourceExist = false;
}
if (File.Exists(dest))
{
f.DestExist = true;
}
else
{
f.DestExist = false;
}
if (f.sourceExist && f.DestExist)
{
FileInfo F1 = new FileInfo(source);
FileInfo F2 = new FileInfo(dest);
long len2 = F2.Length;
if ( F1.LastWriteTime == F2.LastWriteTime)
{
f.bothDateMatch = true;
}
else
{
f.bothDateMatch = false;
}
if (F1.Length == len2 )
{
f.bothSizeMatch = true;
}
else
{
f.bothSizeMatch = false;
}
}
else
{
f.bothDateMatch = false;
f.bothSizeMatch = false;
}
return f;
}
now the problem is with file.LastWriteTime ! this code will work like expected on 2 ntfs disk server to server. but when i back up on usb key both date are different. why the file binary would change? i heard fat disk add like 1-2 seconde to lastwritetime value.
and how i can implemente something safe for compare on any disk?
i know i can do something like this for remove second error but not enough precision
if ( F1.LastWriteTime.ToString("MM/dd/yyyy") == F2.LastWriteTime.ToString("MM/dd/yyyy"))
feel free to tell if the function can be better since its critique that all file on A move on B with a good delta system.
