Question

I have a problem, I use Process.Start to launch an executable, although is it possible to say: if input.txt == 0kb do nothing, else execute process ?

Process.Start("cmd.exe", @"/c test.exe -f input.txt > output.txt").WaitForExit();

Answer 1

Use FileInfo to get the size of the input file and only run the process if it is larger than 0:

FileInfo fi = new FileInfo("input.txt");
if(fi.Length > 0)
{
  Process.Start("cmd.exe", @"/c test.exe -f input.txt > output.txt").WaitForExit();
}