batch works fine but "windows cannot find devcon.exe" in c# program

Question

I have a batch file which disables and enables some driver using windows devcon. when I run this batch file by double-clicking on it it works fine. However, I tried to run it from a C# program that I wrote using this line:

System.Diagnostics.Process.Start("C:/*path to file*/file.bat");

it runs fine until it tries to open the devcon.exe and I get the following message:

after that it continues to run smoothly.

any ideas why it doesn't work from the C# program?

p.s I can't post the batch code due to IP issues...

you could have pasted the batch code, its only text ... however.. it sounds like devcon_64.exe isnt in the path... — BugFinder, Aug 17 '16 at 07:12
yes it is - if it wasn't the batch wouldn't run outside C#, but it does.. — noamgot, Aug 17 '16 at 07:13
depending on where and how you code runs.. which you havent explained it still might not be.. — BugFinder, Aug 17 '16 at 07:15
try to use the full path to devonc_64.exe in your batchfile (get it with `where devcon_64.exe`) Your `%path%` variable might be different. — Stephan, Aug 17 '16 at 07:21
ok, that was apparently the problem. I will write the answer below — noamgot, Aug 17 '16 at 07:51

Thorsten Dittmar · Answer 1 · 2016-08-17T09:08:21.187

The problem is - as often - the "working directory". When you double-click something in the Explorer, the working directory is set to the current folder, so from the batch file's point of view it's current directory is its own directory.

When you execute a C# application, usually the working directory is the directory of the application's exe file, but not necessarily (for example if the application is run using a link, you can specify a different working directory). That's why, to find the application EXE file's directory it is not save to use GetCurrentDirectory.

So what happens is that the application runs the batch file, but with the application's directory, not the batch file's directory, as working directory. An alternative to an explicit cd within the batch file would be to specify the working directory when calling Process.Start.

By using an instance of the `ProcessStartInfo` class as a parameter to the `Process.Start` method specify a valid value in the `WorkingDirectory` property. — Thorsten Dittmar, Aug 17 '16 at 10:35

score 0 · Accepted Answer · answered Aug 17 '16 at 07:55

0

ok, after a little bit of research I found this simple solution: simply changing to the directory of the devcon.exe (using cd command) at the beginning of the batch code, i.e:

cd "C:/*path to the directory of devcon.exe*"
#rest of the code

answered Aug 17 '16 at 07:55

noamgot

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batch works fine but "windows cannot find devcon.exe" in c# program

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