Check if a file is accessable on a shared network drive

Question

Hi,

I have a program that does different things my questions is related to access files in a network mapped drive or a shared folder

the program can run a file msi/exe from the network (network mapped drive or a shared folder) the program can copy file from the network (network mapped drive or a shared folder)

how I can check if the files are accessible before I try to run or copy (in case of a network disconnection, or any other network problem)?

is it enough with File.Exists();

here is an example of my code:

public static bool FileIsOk(string path)
        {
            try
            {
                FileInfo finfo = new FileInfo(path);

                if (finfo.Exists)
                {
                    return true;
                }
                MessageBox.Show("file does not exist, or there is a problem with the network preventing access to the file!");
                return false;
            }
            catch (Exception e)
            {

                MessageBox.Show(e.Message);
            }

            return false;
        }

thanks

Answer 1

The best idea, of course, would be to create local cache of the setup. You cannot trust network connections. They may slow down or break during operation. If everything is run from network, I would say, it's definitely not a safe idea.

But as far as technical question is concerned, File Exists should be fine. A much more descriptive idea has already been discussed to check the existence of a file. Read here.

FileInfo fi = new FileInfo(@"\\server\share\file.txt");
bool exists = fi.Exists;

Answer 2

File.Exists() should be fine, but if you start a large copy operation, there's not a lot you can do if the connection goes down during that process, so you'll want to make sure you code for that.

You should trap the IOException and handle it as you see fit.

EDIT: code to trap IOException:

try
{
   File.Copy(myLocalFile, myNetworkFile);
}
catch (IOException ioEx)
{
   Debug.Write(myLocalFile + " failed to copy!  Try again or copy later?");
}

Answer 3

Don't. Just attempt the operation. It will fail just as fast, and you won't be introducing z timing window problem. Tou have to cope with that failure anyway, why code it twice?