C# file not found in System32 when running in 32 bit -

i'm trying run quser , resulting string. when run code below, see following message the resulting string empty:

'quser' not recognized internal or external command, operable program or batch file.

process p = new process(); p.startinfo.useshellexecute = false; p.startinfo.redirectstandardoutput = true; p.startinfo.filename = "cmd.exe"; p.startinfo.arguments = "/c quser /server:someserver"; p.start();  string output = p.standardoutput.readtoend();  p.waitforexit(); console.writeline(output); 

so full command gets run

cmd.exe /c quser /ser:someserver 

which runs fine when directly, fails c#.

i found similar question no answer here: executing quser windows command in c#; returning result string. question doesn't have quser not recognized message though.

why command not recognized when running code?

i tried running quser command directly so, file not found... strange

process p = new process(); p.startinfo.useshellexecute = false; p.startinfo.redirectstandardoutput = true; p.startinfo.filename = @"c:\windows\system32\quser.exe"; p.startinfo.arguments = @"/server:someserver"; p.start();  string output = p.standardoutput.readtoend();  p.waitforexit(); console.writeline(output); 

we found running in 64 bit, finds it. when running anycpu or 32bit, seems looking in syswow64, when directly tell in system32

alright, found solution.

basically, found in chat, system32 folder redirecting syswow64 on builds, causing quser appear not there.

i have applied workaround.

to workaround it:

1. use following namespace:

   using system.runtime.interopservices; 

2. add following @ top of class file.

   [dllimport("kernel32.dll", setlasterror = true)] public static extern int wow64disablewow64fsredirection(ref intptr ptr); [dllimport("kernel32.dll", setlasterror = true)] public static extern int wow64enablewow64fsredirection(ref intptr ptr); 

3. before making quser call, make following calls:

   intptr val = intptr.zero; wow64disablewow64fsredirection(ref val); 

4. after making quser call, revert changes:

   wow64enablewow64fsredirection(ref val); 

full sample:

using system.runtime.interopservices;  ... namespace csharptests {     public class program     {         [dllimport("kernel32.dll", setlasterror = true)]         public static extern int wow64disablewow64fsredirection(ref intptr ptr);         [dllimport("kernel32.dll", setlasterror = true)]         public static extern int wow64enablewow64fsredirection(ref intptr ptr);         [dllimport("kernel32.dll", setlasterror = true)]         public static extern int wow64revertwow64fsredirection(ref intptr ptr);          static void main(string[] args)         {             intptr val = intptr.zero;             wow64disablewow64fsredirection(ref val);             process p = new process();             p.startinfo.useshellexecute = false;             p.startinfo.redirectstandardoutput = true;             p.startinfo.filename = "cmd.exe";             p.startinfo.arguments = "/c quser";             p.start();              string output = p.standardoutput.readtoend();              p.waitforexit();             console.writeline(output);             wow64revertwow64fsredirection(ref val);             p = new process();             p.startinfo.useshellexecute = false;             p.startinfo.redirectstandardoutput = true;             p.startinfo.filename = "cmd.exe";             p.startinfo.arguments = "/c quser";             p.start();              output = p.standardoutput.readtoend();              p.waitforexit();             console.writeline(output);         }     } } 

results:

username              sessionname        id  state   idle time  logon time ebrown                console             1  active      none   05/18/2015 09:2 1 'quser' not recognized internal or external command, operable program or batch file. 

as can see, first quser call succeeded, told os stop redirecting syswow64, once re-enabled it, call failed.

i'm sure there's reason protection, don't need it.

additional considerations:

it prudent of implementing pattern first detect if workaround needs applied. such detection done using following boolean:

environment.getfolderpath(environment.specialfolder.systemx86).contains("system32") 

in case of false boolean, need check that:

file.exists(@"c:\windows\system32\filenamehere") 

in case:

file.exists(@"c:\windows\system32\qdisk.exe") 

adapted from:

http://blog.airesoft.co.uk/2010/09/wow-disabling-wow64-fs-redirection-can-cause-problems-who-knew/

https://msdn.microsoft.com/en-us/library/windows/desktop/aa384187%28v=vs.85%29.aspx