Escape ampersand while executing the script

Devi

I am trying to execute the PowerShell from WPF by pointing to the powershell.exe path. I have the following code

The error I am getting is The ampersand (&) character is not allowed. The & operator is reserved for future use; wrap an ampersand in double quotation marks ("&") to pass it as part of a string.

http://blog.heshamamin.com/2009/04/calling-powershell-script-in-path-with.html

string PSPath = string.Concat(Environment.SystemDirectory, "\\WindowsPowerShell\\v1.0\\powershell.exe");
string ScriptPath = string.Concat(PSPath, " -ExecutionPolicy Unrestricted -Command ");
string CommandPath = string.Concat("\"& {&'", regex[0].ToString(), "'", regex[1].ToString(), "}\"");
ScriptPath = string.Concat(ScriptPath, CommandPath);
using (Process p = new Process())
{
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.FileName = PSPath;
p.StartInfo.Arguments = ScriptPath;
p.Start();
string error = p.StandardOutput.ReadToEnd();
}

My script looks as follows:

C:\WINDOWS\system32\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Unrestricted -Command "& {&'C:\TestPS\Testps1' -Arg1 -Arg2}"

which is executing fine when I directly copy paste into PowerShell, but not from the Win froms application.

8 Replies

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Dorababu Meka9y ago
Accepted answer
Here is the update code attaching the solution by doing some minor changes
+1
Devi9y ago
Any update please

Update code

https://drive.google.com/open?id=0B6o552kozQh4VkdMZ3M5TElvY1E
0
Amit Gupta9y ago
@Devi,
As your mentioned in your link (for calling powershell). I believe that you might not have noticed that & (ampersand) is used to occupy the space between your ps1 file path. as you are ps1 file path does not contain any space between the string, you can skip the (&) and go for the execution of your file.

To need more reference on calling powershell, google it, you can find nth links for this. also check the below link for your kind consideration.
http://stackoverflow.com/questions/2035193/how-to-run-a-powershell-script

Hope this helps
0
Amit Gupta9y ago
Hey Devi
C:\WINDOWS\system32\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Unrestricted -Command "& {&'C:\TestPS\Testps1' -Arg1 -Arg2}"

As mentioned in your above script, ampersand is not wrap with double quote. Use string.Format and cover your ampersand with double quote like \""&\""
+1
Devi9y ago
Anish I am working with PowerShell using WinForms also I posed the blog reference how can we over come the issue. But some how I am not able to work it out from Winforms application.
0
Devi9y ago
Amit I didn't get you, I know how to use string.format but how it changes the execution I didn't get. Do I need to get that ampersands in string.Format ?

More over I am trying to execute PowerShell script so can you clearly explain me
0
Amit Gupta9y ago
As you had already mentioned and indicated in your error to wrap & in a double quote. Make it wrap

However, to be more flexible while passing any argument which contains user value, format your string, that not only provide you proper reading but also you can manage efficiently.
See the demo snippet

var arg = string.Format (" firstname ={0}, lastname ={1}", txtfirst.Text, txtLast.Text);
0
Anish Kumar9y ago
Hi Devi,

before passing your script path , you have to encode your path ,Finally decode the path.

For encoding use this..
HttpServerUtility.UrlEncode(your path)
For Decode use this...
HttpServerUtility.UrlDecode(your path)
I hope , it will work...
0

Escape ampersand while executing the script

HttpServerUtility.UrlEncode(your path)

HttpServerUtility.UrlDecode(your path)