Re: why cant I run powershell script from current directory - C# Discussion Boards

Many of what you'd probably think of as common to .NET dependencies are out there in various forms.

Dependency chaining has changed a little bit though. Mostly for the better.

For the most part, transients can now be consumed without a direct reference and very little effort.

If you have a nuget that then has <some nuget=""> as a dependency and you are already including that original nuget package, you do not generally also need a direct <some nuget=""> package reference in there... dotnet build will just figure that all out. (Assuming packagereference, but don't do packages.config anymore, ever)

the following is part for a c# code that I am working on:

C#

// Specify the PowerShell script filename
    powerShellScriptFilename = @"C:\Users\sherz\OneDrive\Downloads\enableTouchScreen.ps1";

// Create process start info
ProcessStartInfo psi = new ProcessStartInfo
{
    FileName = "powershell.exe",
    Arguments = $"-NoProfile -ExecutionPolicy Bypass -Command \"{powerShellScriptFilename}\"",
    RedirectStandardInput = false,
    RedirectStandardOutput = false,
    RedirectStandardError = false,
    CreateNoWindow = true,
    UseShellExecute = true, //need to be set to true for 'Verb' to function
    Verb = "runas" //run application as Administrator
    //WorkingDirectory = Directory.GetCurrentDirectory()
};

// Create the process
Process process = new Process { StartInfo = psi };

// Start the process
process.Start();

With this above the script run as expected.

The issue is if I move the script to the 'currentDirectory' (ie the Project debug folder) the script is not executed.

I already tried updating 'powerShellScriptFilename' with the corresponding absolute path, script still worth execute.

As the code works if I chose a different location, it seems to me that there may be some restriction or filepath length issue.

My aim is to try and avoid hard coding the filepath to the script and I would like my program to pick its current directory to find the script and run it.

How can I test/do that if it is not possible to do that from the debug folder?

still quite new to C# but keen to learn! Smile | :)

modified 2-Feb-24 17:36pm.

How about:

C#

powerShellScriptFilename = Path.GetFullPath("enableTouchScreen.ps1");

ProcessStartInfo psi = new ProcessStartInfo
{
    FileName = "powershell.exe",
    Arguments = $"-NoProfile -ExecutionPolicy Bypass -Command \"{powerShellScriptFilename}\"",
    RedirectStandardInput = false,
    RedirectStandardOutput = false,
    RedirectStandardError = false,
    CreateNoWindow = true,
    UseShellExecute = true, //need to be set to true for 'Verb' to function
    Verb = "runas" //run application as Administrator
};

Process process = Process.Start(psi);

Beyond that, we need to know what "not working" means. Provide the full details of the error you're getting. If it's a PowerShell error, then you may need to provide the relevant parts of your PowerShell script as well.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

thank you. will try that when I get home.

"not working" means not working. not much more I can provide as I receive/can see no errors.

as you may have guessed from the fileames, the script enables my screentouch and that is how I know it was not successfull when I tried the current directory path.

with the original directory path, I would be able to enable my screentouch...

Sherzaad13291325 wrote:
move to the script

Presumably you mean 'enableTouchScreen.ps1' for script.

Several obvious possibilities.
- You did not in fact move it.
- You did not update the path in your code.
- The path that you did update is wrong.
- You did not recompile the code after updating the path.

As one check for errors and probably one that I would always do in this type of code is to verify that the script (the path) exists before attempting to run it.

Additionally I might be inclined to check permissions also.

Doing both of the above is required if you intend for this code to eventually run in a Windows Service or a IIS App Pool.

Sherzaad13291325 wrote:
the code works if I chose a different location, it seems to me that there may be some restriction or filepath length issue

My suspicion was right! turns out is WAS a filepath length. Converted the 'fullpath' to its 'shortpath' and code is now running as it did before Smile | :)

modified 3-Feb-24 7:43am.

Based on the code you posted, no, it wasn't filepath length. The max length of a filepath is 260 characters. The max length of the Windows command line is 32K, and I seriously doubt your command line was that long.

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Dave Kreskowiak

You are right that the OP has not provided enough info for us to certainly conclude that it was a path length problem. But we certainly cannot reject it.

Then file name of his script, "enableTouchScreen.ps1", is 21 chars. He reports that when it is moved to "the 'currentDirectory' (ie the Project debug folder)", it won't work. If the length of 'cd' exceeds 238 chars, the full script file name would exceed 260 chars.

I certainly have seen project directory paths exceeding 238 chars; in my last job, the naming rules made it more or less the standard. What surprises me more is that the OP does not run into this problem with other files in his project as well. Maybe it is set up will all relative naming (and no tools expand it to an absolute path), or all files are located in other directories with shorter paths, or all the other tools are prepared for long file paths.

260 chars was the old DOS/FAT limit. As long as you use new Windows file system APIs that can handle longer NTFS paths, they can be up to approx. 32 Ki characters. The 260 length is not really in NTFS or Windows, but in individual programs using old APIs. These APIs have not been extended to long file names because lots of old program have allocated 261 chars for a file path buffer, frequently with no overrun check as that is the maximum length. If an old API used to return names limited by MAX_PATH after a minor update starts returning names of several hundred or thousand characters, then you would have a buffer overrun.

It is a pity that the myth of Windows being limited to 260 chars are still living. It makes lots of programmers continue making 261 char allocations, and the old APIs that should have been marked as deprecated 20 years ago and removed 10 years ago. Backwards compatibility is great (and Windows is far better at it than competing OSes!) but sometimes it goes too far.

Religious freedom is the freedom to say that two plus two make five.

trønderen wrote:
260 chars was the old DOS/FAT limit. As long as you use new Windows file system APIs that can handle longer NTFS paths, they can be up to approx. 32 Ki characters. The 260 length is not really in NTFS or Windows, but in individual programs using old APIs.

And that's why I always say the limit is 260 characters. Yes, if using the new stuff, it's 32K, but developers, all too commonly, don't use the newer API's because the code they wrote at least a decade ago never gets updated. I've seen it way too often, even today.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.
Dave Kreskowiak

But by keeping that old myth alive (stating unconditionally that "The max length of a filepath is 260 characters", with no reservation, like an absolute truth), you contribute to the problem. Lots of programmers believe that as long as they allocate a 261 char buffer for the file name, they are safe and can handle all the paths there are.

But they cannot. Windows software can create longer paths, as the OP experienced.

I would much prefer to make a reference to the long filenames, and add a warning: Beware that if the path exceeds 260 char, then software using old FAT oriented calls to obtain the file path might fail.

Trying to keep the solution to the problem secret, because some programmers is not aware of it, is no good way to bring the world forward. In my eyes, that is.

Religious freedom is the freedom to say that two plus two make five.

No, I don't. Developers who refuse to update their code contribute to the problem, and yes, I still see those problems today. I mention the limit for compatibility reasons.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.
Dave Kreskowiak

The problem is not due to Dave's comments, but rather the developers' failure (or is that refusal) to make use of official documentation. We see plenty of questions where the OP says they cannot find something via Google. And yet when we repeat the search it takes us straight to the MSDN page in question.

Richard MacCutchan wrote:
The problem is not due to Dave's comments, but rather the developers' failure (or is that refusal) to make use of official documentation.

Or, the problem is that when some experienced programmer states "The limit IS 260 characters!" (and that is just a fact), the inexperienced programmer sees no need to go to the official documentation to learn that the experienced programmer had given him incorrect information 'just to be on the safe side'.

I willingly admit that when a mate tells me how to do something, or how I can not do it (e.g. using longer paths), I frequently take that as a valid piece of information. I do not always verify against the official documentation every piece of information or every advise I receive. Maybe I should, but that would take a lot of time. I allow myself to learn from others.

Religious freedom is the freedom to say that two plus two make five.

Dave Kreskowiak wrote:
The max length of a filepath is 260 characters. The max length of the Windows command line is 32K

I didn't find an authoritative source but googling I did find recent posts that suggests that the length limit for Powershell scripts is 260 characters.

Presumably the command execution would fail then. Probably with a return value of '2'? (File not found?).

float n = 0.2f;
Console.WriteLine( $"{n:F2}: {Math.Round( n, 0 ):F2}" );

n = 0.5f;
Console.WriteLine( $"{n:F2}: {Math.Round( n, 0 ):F2}" );

n = 0.6f;
Console.WriteLine( $"{n:F2}: {Math.Round( n, 0 ):F2}" );

n = 1.5f;
Console.WriteLine( $"{n:F2}: {Math.Round( n, 0 ):F2}" );

n = 1.2f;
Console.WriteLine( $"{n:F2}: {Math.Round( n, 0 ):F2}" );

n = 1.7f;
Console.WriteLine( $"{n:F2}: {Math.Round( n, 0 ):F2}" );

Answer:

0.20: 0.00
0.50: 0.00
0.60: 1.00
1.50: 2.00
1.20: 1.00
1.70: 2.00

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

Take a look at IEEE 754 rounding. Wikipedia (IEEE 754 Rounding rules[^]) is a good starting point, but not necessarily the ultimate answer.

For any calculation with bits beyond what can be represented in the result definition, as long as they are available they should determine rounding. However, if the true result of a calculation is exactly one half of the resolution (so you do not have any hidden bits to help you), experts on error propagation will tell you that rounding up or down at random, or e.g. every second time, will reduce the average error (when we are talking about zillions of calculations and result roundings).

Religious freedom is the freedom to say that two plus two make five.

As always, it depends. The Round function can use different rules depending on what you pass it. It's all covered in the documentation on Round[^]. Just make sure you have the correct framework you're using selected in the top left of the page.

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.
Dave Kreskowiak

It does both, does it not?
0.5 => 0
1.5 => 2
2.5 => 2
3.5 => 4
etc.

This was mainly Carl Friedrich Gauss's idea. Basically, its a choice you make, and you could choose differently. Your computer might do it differently...

The question is not how to round.

The question is what exact business rules are being addressed.

This is much more true when dealing with currency of any sort. Often (always?) with currency rounding is covered by laws, regulations and/or contracts. And in complex systems one must do a data dip to determine the exact rule that applies for that case (always with a timestamp.)

I did not ask "how" ... I learned to add 0.5 or 0.05 or .005 in elementary school. "Should" implies Generally Accepted Accounting Practices (GAAP) ... or what every search generally says about "rounding".

I don't expect that every person who learned these "rules" goes back to check every day to see if "convention" has changed.

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

Not sure what your original post was referring to.

But my point is that business rules, not code usage, determines how rounding should happen. So no one should ever code rounding without understanding the business rules that require it.

I think you just want to add your 2 cents regardless of whether you understand the "original post" or not.

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

MidpointRounding Enum (System) | Microsoft Learn[^]

My "question" was more philosophical than technical.

I have built ERP systems from the ground up that passed audit from national accounting firms. My "naive" approach to rounding was never a problem. (And this was "before" .NET)

The concept of randomly deciding to go up or down, is not "determinate" from an auditing point of view.

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

There is a good option there which is not random: always round to the even number. Not being an accountant I don't know if auditors have their own rule.