Question

I’m writing a CLI program that on an event, runs Process.Start() on a user-defined file. This respects %PATH%, but File.Open() does not.

Basically, when the program is launched, I run a variety of checks. One of the checks I want is that this file exists and can be opened by the current user, ala:

try
{
    fs = File.Open(Run, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
    Run = args[++i];
}
catch(TheVariousExceptions){ .... }
finally
{
    if(fs != null)
        fs.Close();
}

The exceptions are also handled at the time of Process.Start(), but this may not be invoked until a while after, when the user might have configured the program and left it to run. So I’d like to first run the check like above. Problem is, it doesn’t take %PATH% into account.

Any ideas?

Answer 1

This is how I managed to do it.

static Process TestProc = new Process();
static ProcessStartInfo TestProcStart = new ProcessStartInfo();
try
{
    TestProcStart.WindowStyle = ProcessWindowStyle.Hidden;
    TestProcStart.FileName = args[++i];
    TestProc.StartInfo = TestProcStart;
    TestProc.Start();
    TestProc.Kill();
    Run = args[i];
}
catch(Win32Exception e)
{
    switch(e.NativeErrorCode)
    {
        case 2: Console.WriteLine("ERROR: File " + args[i] + " not found!"); return;
        case 5: Console.WriteLine("ERROR: Access denied to " + args[i] + "!"); return;
        default: Console.WriteLine("ERROR " + e.NativeErrorCode + ": " + e.Message); return;
    }
}