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Changing the current working directory of cmd (from a child process)

So I am trying to write a cd -like program that can be executed using cmd and after it exits the working directory of the calling cmd process should be changed.
Now before this post is flagged as a duplicate: I am aware of this and this question that were asked for pretty much this exact problem but using Linux instead of Windows as well as being pretty broad and unspecific, and I am aware that similar limitations apply to Windows as well (changing the working directory of my process will not change the parent’s working directory).
There is actually is a working solution to this for linux. However it is using gdb for this, and I would like to achieve this task using only built-in Windows utilities (WinAPI, dotNET, etc.).
What I have tried so far
I did manage to use Cheat Engine and the OpenProcess() / WriteProcessMemory() WinAPI funtions to successfully override cmd's working directory. However this solution feels sloppy and doesn't work well (or at least requires more work to be put into.)
My question
Is there a different (maybe simpler?) way on Windows to achieve this? Like a way to invoke/inject code to the cmd process to execute cd whatever\directory\I\want directly without overriding its memory? I have seen the CreateRemoteThread() functions however I didn't manage to find a way to put them to use.
FYI: I am mainly using C# but C/C++ solutions should help too as long as they are based on the native Microsoft libraries.

This post describes a Windows implementation of a function that launches a child process, creates pipes to stdin and stdout from which a command is sent, and a response is returned. Finally, once all response is captured the child process is terminated. If this sounds familiar it is similar in concept to Linux's popen() function with the exception that this implementation was specifically created to capture the response into a buffer of any command that returns one. (Also included is a variant for use when no-response is expected or needed.)
The full source can be adapted for use within a standalone executable, or as an API. (.dll) Either way, the resulting functions accept and process any command using standard Windows CMD syntax. The function cmd_rsp(...) returns the Windows response via stdout into a self-sizing buffer.
The exported prototypes are:
int __declspec(dllexport) cmd_rsp(const char *command, char **chunk, unsigned int size);
int __declspec(dllexport) cmd_no_rsp(const char *command);
A simple use case when capturing a response:
#include "cmd_rsp.h"
int main(void)
{
char *buf = {0};
buf = calloc(100, 1);//initialize to some initial size
if(!buf)return 0;
cmd_rsp("dir /s", &buf, 100);//buffer will grow to accommodate response as needed.
printf("%s", buf);
free(buf);
return 0;
}
A simple use case when response is not needed:
#include "cmd_rsp.h"
int main(void)
{
cmd_no_rsp("cd C:\\dir1\\dir2");
return 0;
}
A detailed description of purpose and usage is described in the link provided above. To illustrate, here are a few sample command inputs, each in this case change the working directory, then execute a command from that directory:
A command to change to sqlite directory, then execute a query:
cd c:\\tempExtract\\sqlite\\Tools\\sqlite-tools-win32-x86-3250300 && sqlite3.exe .\\extract.db \"select * from event, eventdata where eventType=38 and eventdata .eventid=event.eventid\
A command to change to teraterm directory, then execute a script:
"c:\\Program Files (x86)\\teraterm\" && ttpmacro c:\\DevPhys\\LPCR_2\\play\\Play.ttl
A command to change directory then execute a command to send multiple digital acquisition channel settings.
cd C:\\Dir1\\Dir2\\Dir3\\support\\Exes\\WriteDigChannel && .\\WriteDigChannel.exe P1_CH0 1 && .\\WriteDigChannel.exe P1_C H0 0 && .\\WriteDigChannel.exe P1_CH0 1
A recursive directory search from a specified location:
cd C:\\dir1\\dir2 && dir /s /b

I got it working. As was suggested SendInput finally did the trick.
I used a combination of WinAPI calls to GetForegroundWindow() / SetForegroundWindow() and the Windows Forms System.Windows.Forms.SendKeys.SendWait() Method to achieve what I wanted:
Upon calling my cd-wrapper program (sd.exe) and providing my custom target directory (~/ home) it generates the corresponding command along with the "Enter-Pressed-Event" to be sent to it's parent cmd process.
Here's the complete C# code:
if (args.Length != 1)
{
Console.WriteLine(Directory.GetCurrentDirectory());
return;
}
string targetDirectory = args[0];
string command = string.Empty;
if (targetDirectory.Equals("~"))
{
command = #"pushd C:\Users\fred\Desktop";
}
else if (!Directory.Exists(targetDirectory))
{
Console.WriteLine("I/O Error: No such file or directory.");
return;
}
else
{
command = #"cd " + targetDirectory;
}
Target target = Target.Create(Process.GetCurrentProcess().GetParentProcess());
target.SendKeys(command + "{ENTER}", true);
Note that I kind of started to write a complete Framework for this and similar problems alongside this project that contains all my different approaches to this question and the low level WinAPI calls as well as the Extension methods to get the parent process :D
As it would be a bit overkill to paste all of it's code in this answer, here's the GitHub. If I can find the time I'll go ahead and optimize the code, but for now this'll do. Hope this helps anyone encountering a similar problem :)
Edit:
An even "cleaner" way is to use dll injection to directly make cmd switch it's working directory. While it is a lot harder to get working it has the advantage of not littering the cmd command history as compared to the approach described above. In addition to that cmd seems to be aware of any changes to it's current working directory, so it automatically updates the prompt text. Once I have a fully working example, that allows to dynamically specify the target directory I will post it here :)

pyinstaller .exe works locally but fails when called by C#?

I have created a script using Python2.7 and compiled it using pyinstaller into an exe of the same name, in this case "GeneralStats.py" turns into "GeneralStats.exe" using --onefile and -w arguments.
When called with C# I use:
var pythonDirectory = (Directory.GetCurrentDirectory());
var filePathExe1 = Path.Combine(pythonDirectory + "\\Python\\GeneralStats.exe");
Process.Start(filePathExe1);
When called outside of C#, so in my local files I can run the .exe and the result is a text file with lots of values in (Running correctly).
However, when ran with C# in this format, I get an error that "GeneralStats returned -1!"
Which I have had issues with before, but it was a simple python error that when I returned to my code and ran it, I would receive an error that I overlooked.
This time my python code returns no errors and works outside of C#.
Any ideas of why this could be? I can provide any code or file directories necessary, please just ask if you feel it would help with debugging.
EDIT:
Solved by removing:
var filePathExe1 = Path.Combine(pythonDirectory + "\\Python\\GeneralStats.exe");
Process.Start(filePathExe1);
And replacing with:
ProcessStartInfo _processStartInfo = new ProcessStartInfo();
_processStartInfo.WorkingDirectory = Path.Combine(pythonDirectory + "\\Python");
_processStartInfo.FileName = #"GeneralStats.exe";
_processStartInfo.CreateNoWindow = true;
Process myProcess = Process.Start(_processStartInfo);

You need to set the working directory for the Process - it is probably trying to load files from its working directory but isn't finding them.
See, e.g. this:
Use the ProcessStartInfo.WorkingDirectory property to set it prior to starting the process. If the property is not set, the default working directory is %SYSTEMROOT%\system32.
Set it to the path where GeneralStats.exe is.

How safe is it to open file and wait for change in a C# program

In my C# WinForms app, users are allowed to create documents and show them in other programs (typically, Word or Excel) and once users close it (if modified), the file is saved by the app in a specific database.
I use the following code to open the file with the correct default program:
string tmpPath = "myTempDoc.xyz"; // extension might vary
FileInfo f = new FileInfo(tmpPath);
DateTime tmpStamp = f.LastWriteTimeUtc;
System.Diagnostics.Process p = System.Diagnostics.Process.Start(tmpPath);
p.WaitForExit();
f = new FileInfo(tmpPath);
if (f.LastWriteTimeUtc > tmpStamp.AddSeconds(1)) {
db_store_file(tmpPath); // stores the modified version of the file in a database
}
// ---- REMAINING CODE AFTER CLOSING ---
doSomeStuff();
I am a bit concerned with the WaitForExit() method. Users need to close the default program for the app to continue. This is ok, but is it really safe?
What if the user (or some process) kills the App during the WaitForExit? For sure, remaining code doSomeStuff() will NOT be executed so I need to make sure all is done BEFORE starting the process... But is there any additional risk?
I know about FileSystemWatcher could be an alternative... But this allows the user to continue in the app without saving changes, which is an additional risk I'd rather not take...
Is the above method safe? Or is there a standard method for letting users modify files in their default program and, once done, retrieve these changes in the database?

Execute all .bat files in the current folder and delete them after execution

I am a newbie programmer wanting to make averaging videos. I have made a program to create n .bat files doing the average of n images, now I would like to execute them as fast as possible.
The .bat files are independent.
I am in a Windows environment.
I have looked at C# multi threading (threadpool, parrallel.for, parralel.foreach etc), but none of the functions there seems to work. I have no illusion that it's me who's doing something wrong though.
Powershell has a function doing what I want, but only for other powershell commands.
The code I have now that mostly works is:
(complete solution at https://github.com/Madsfoto/ParallelExecutionForEach )
var paths = Directory.GetFiles(Directory.GetCurrentDirectory(), "*.bat"); // have a list of all .bat files in the current directory
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo.CreateNoWindow = true;
proc.StartInfo.UseShellExecute = false; // above is to not see the cmd window
proc.StartInfo.WorkingDirectory = Directory.GetCurrentDirectory(); // It's easier than having to specify where this program will be run.
Parallel.ForEach(paths, new ParallelOptions { MaxDegreeOfParallelism = 4 }, currentFile => // 4 is set because I have 4 cores to use
{
proc.StartInfo.FileName = currentFile; // Set the currentfile as the one being executed. currentFile is the name of the .bat file to execute
proc.Start(); // execute the .bat file
proc.WaitForExit();
File.Delete(currentFile);
});
I get System.InvalidOperationException: No process is associated with this object and System.UnauthorizedAccessException’s when I run more than 3-4 processes at the same time.
I suspect that it is the WaitForExit() that is giving me problems, but do not have the skills to debug it.
I have looked at Threading.Task as well, but my skill is not good enough to use it.
So the solution I am after is as follows:
Execute either 1 input file with x lines of independent action or x files with 1 action, with a limit of y processes at the same time either set at compile or runtime.
Programming language is not important to me, although my preference is understandable C#.
(The result is something like https://www.youtube.com/watch?v=ph6-6bYTgs0, with n frames averaged together)

The solution was to move the
proc.Start(); // execute the .bat file
proc.WaitForExit();
try
{
File.Delete(FileName);
}
catch
{
}
code into it's own function (with the bookkeeping stuff (defining proc etc)).
The File.Delete() was the culprit, it turns out that there might be a bug in the Parallel.ForEach, but I have been unable to reproduce it reliably (experimenting gives errors ~0.01% of the time), but this way it works. It does require people to rerun the executable, but that is a burden I can justify pushing to the user.
The github link has been updated with a working version.

Issues about files or folders in use: get the name of another Process that use file or folder

I using C# .NET , vs 2008 , .net 3.5
For me, is difficult, but I need sample code in C# for this:
Check if a file or a folder is in use
If file or a folder is in use, the name of Process that use it
For example, in my issue.
I try delete file, and I get "The process cannot access the file 'XYZ' because it is being used by another process." Exception.
File.Delete(infoFichero.Ruta);
I want check if a file is in use, and the name of Process that use it.
I need sample code, source code, please. I dont want use c++, I dont know c, c++, unmanaged code, or WinApi. I want use only C# code (managed code .net).
I have read several references but not get sample code source,
How to check if a file is in use?
Emulate waiting on File.Open in C# when file is locked
http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/9dabc172-237a-42db-850e-ada08885a5d5
How to check if a file is in use?
Easiest way to read text file which is locked by another application
Using C# is it possible to test if a lock is held on a file
EDIT:
From Yan Jun - MSFT
string path = "D:\\temp2.xlsx";
foreach (Process c in Process.GetProcesses()) {
if (c.MainWindowTitle.Contains(Path.GetFileName(path))){
MessageBox.Show(c.ProcessName);
return;
}
}
try{
FileInfo f = new FileInfo(path);
f.Delete();
}
catch (Exception ex){
MessageBox.Show(ex.Message);
}
...
But it is difficult get solution for all 100% issues.
Problem if c.MainWindowTitle == null or not contains filename.
Problem for shared folder in another machine, PC, server,... like:
File.Delete(#\desiis\TEmporal\Project\script.targets);
any sample code, I ask for help gurus, MVPs, anyone.
UPDATE: the same issue for a folder

There's not going to be a way to find the process that has the file opened without stepping into the WinApi, I don't think. And as far as checking whether its in use, the only thing you can really do, as the SO questions you linked to state, is to wrap the file access attempts in a try/catch block.
The code to find which file has it opened is likely to be ugly, but there may be an API out there that wraps this up nicely. There are 3rd party utilities that will tell you this (Unlocker being the best known example). You can also use ProcessExplorer to search for open file handles by the filename. Those don't really help you though.
The short answer of what I'm trying to get across here is you have the answer for the first part of your question in the SO questions you already linked, and the second part would probably require WIN32 calls, which you want to avoid, but you're probably going to have to get your hands dirty in Win32... Still want help?
EDIT: You could shell out to sysinternals Handle utility. You would need to get the output of that command and parse it yourself. You can read the executed process's output like this
string result = proc.StandardOutput.ReadToEnd();
The issue with this is you're going to get a license agreement popup the first time you run the Handle utility. Not to mention the whole licensing issues if this is something you hope to deploy...
If you're still interested, I can show you how you'd go about this.
EDIT: Here's a runnable program that will find the exe name and pid of any program that has an open handle to a file. I added comments, but can elaborate further if necessary. I use Regular Expressions here to parse the output as that makes the most sense given the task at hand.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Text.RegularExpressions;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
ProcessStartInfo si = new ProcessStartInfo();
si.FileName = "handle.exe"; //name of the handle program from sysinternals
//assumes that its in the exe directory or in your path
//environment variable
//the following three lines are required to be able to read the output (StandardOutput)
//and hide the exe window.
si.RedirectStandardOutput = true;
si.WindowStyle = ProcessWindowStyle.Hidden;
si.UseShellExecute = false;
si.Arguments = "test.xlsx"; //this is the file you're trying to access that is locked
//these 4 lines create a process object, start it, then read the output to
//a new string variable "s"
Process p = new Process();
p.StartInfo = si;
p.Start();
string s = p.StandardOutput.ReadToEnd();
//this will use regular expressions to search the output for process name
//and print it out to the console window
string regex = #"^\w*\.EXE";
MatchCollection matches = Regex.Matches(s, regex, RegexOptions.Multiline);
foreach (var match in matches)
{
Console.WriteLine(match);
}
//this will use regex to search the output for the process id (pid)
//and print it to the console window.
regex = #"pid: (?<pid>[0-9]*)";
matches = Regex.Matches(s, regex, RegexOptions.Multiline);
foreach (var obj in matches)
{
Match match = (Match)obj; //i have to cast to a Match object
//to be able to get the named group out
Console.WriteLine(match.Groups["pid"].Value.ToString());
}
Console.Read();
}
}
}

There is no purely managed way to do this. You have to use some low-level APIs through P/invoke or similar.
There's good information here on a way to do it, but it's C++ code. You'd have to do the porting yourself.
http://www.codeproject.com/KB/shell/OpenedFileFinder.aspx
Note there are some complex issues with this, namely the issues around kernel vs. userspace memory. This is not a simple problem you're trying to solve.

Try the windows Process Explorer:
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx
Won't let you do it from code, but at least you can figure out what the source of your locks are.