How to read command line arguments of another process in C#?

Question

How can I obtain the command line arguments of another process?

Using static functions of the System.Diagnostics.Process class I can obtain a list of running processes, e.g. by name:

Process[] processList = Process.GetProcessesByName(processName);

However, there is no way to access the command line used to start this process. How would one do that?

Answer 1

If you did not use the Start method to start a process, the StartInfo property does not reflect the parameters used to start the process. For example, if you use GetProcesses to get an array of processes running on the computer, the StartInfo property of each Process does not contain the original file name or arguments used to start the process. (source: MSDN)

Stuart's WMI suggestion is a good one:

string wmiQuery = string.Format("select CommandLine from Win32_Process where Name='{0}'", processName);
ManagementObjectSearcher searcher = new ManagementObjectSearcher(wmiQuery);
ManagementObjectCollection retObjectCollection = searcher.Get();
foreach (ManagementObject retObject in retObjectCollection)
    Console.WriteLine("[{0}]", retObject["CommandLine"]);

Answer 2

If you're targeting Windows XP or later and you can afford the overhead of WMI, a possibility would be to look up the target process using WMI's WIN32_Process class, which has a CommandLine property.

Answer 3

Process.StartInfo returns a ProcessStartInfo object that allegedly but not necessarily has the arguments in the Arguments property.

Answer 4

Are both projects yours? Could you modify the source for the process you're trying to examine to make it give you its command-line arguments, rather than trying to read them from somewhere outside of that process?