blh83
16th February 2011 20:47 UTC

ExecWait runs in wrong context?
I am attempting to rename a dll that was incorrectly placed into the System32 directory by AdvancedInstaller ("Advanced" is not the word I would use; there's a reason I switched to NSIS). I have no problems with the renaming if I launch a command line manually. If I use the Rename command in NSIS I have no success. So I tried using either "Exec" "ExecWait" or "nsExec::Exec" in order to run the command 'ren' (eg nsExec::Exec '"ren" file file.old'). Again nothing happens.

Therefore I ran the following

ReadEnvStr $R0 COMSPEC
Exec '"$R0" start cmd.exe'

so that I could interact with the command prompt spawned by the installer. If I search for the dll in the System32 directory, it can't find it even though in Windows Explorer it is clearly there. Doing a directory list in the command prompt doesn't show the dll in the list. This gives the impression that the command prompt being launched from the installer is not launching as a normal command prompt does if launched manually.

For the heck of it I tried running 'setshellvarcontext' to 'current' (which is admin in my case) with no success. Are there any ideas as to why I can't rename the dll from the installer but have no problems when launching a command prompt normally? They should behave the same right? Thanks in advance for any input.

Anders
16th February 2011 21:08 UTC

Exec* runs child process in the same context as the installer.

Are you on x64?

blh83
16th February 2011 22:20 UTC

Oh I see what you are saying. Yes I am on an x64 machine. Is there a way to get around the 32-bit 64-bit issue when launching the command or running Exec?

Afrow UK
16th February 2011 22:44 UTC

If Rename isn't working then you probably forgot to disable WOW64 file system redirection. Use DisableX64FSRedirection from x64.nsh.

Stu

blh83
16th February 2011 23:59 UTC

Thank you very much Afrow, that was what I needed. The 32-bit 64-bit issue that Anders was eluding to is still a question for me, however, that is likely a can of worms.

Afrow UK
17th February 2011 00:12 UTC

There's a 32-bit version of cmd.exe too. You would have executed that instead.

Stu