Program.cs

using System;
using System.IO;
using System.Collections.Generic;
using System.Diagnostics;

namespace foreachfile
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            string path;
            string cmd;
            string cmdargs;
            string[] files;

            if (args.GetLength(0) < 3)
            {
                MainClass.printUsage();
                return;
            }
            path = args[0];
            cmd = args[1];
            cmdargs = args[2];

            try
            {
                files = Directory.GetFiles(path, "*", SearchOption.AllDirectories);
            }
            catch(Exception ex)
            {
                Console.WriteLine("Something went wrong while trying to accumulate the list of files :(");
                Console.WriteLine(ex.ToString());
                return;
            }

            try
            {
                foreach(string file in files) 
                {
                    Console.WriteLine("Working on '" + file + "'");
                    var proc = Process.Start(cmd, cmdargs.Replace("$1", file));
                    proc.WaitForExit();
                    if(proc.ExitCode == 0) {
                        Console.WriteLine("job worked (i guess?)");
                    } else {
                        Console.WriteLine("job finished, returned exit code " + proc.ExitCode + "; is that bad?");
                    }
                }
            }
            catch(Exception ex)
            {
                Console.WriteLine("Something went wrong while trying to run the command :(");
                Console.WriteLine(ex.ToString());
            }

        }

        public static void printUsage() {
                        Console.WriteLine("USAGE: foreachfile.exe PATH_TO_FIND_FILES_IN COMMAND_TO_RUN \"PARAMETERS FOR COMMAND, USE $1 AS PLACEHOLDER FOR FILENAME MIND THE QUOTATION MARKS\"");
        }
    }
}