Get-Command & version number - powershell

I have a need to check to see if a program is installed by looking at an EXE file. Some goofy programs don't behave nicely and put rational info in the registry. I have Get-Command $path working, and it allows me to get version info as a property which is also nice. However, I want to do some validation, making sure the file is a valid file. So I tried taking a TXT file and just changing the extension to EXE, and kind of expected Get-Command to throw an exception. But no, it works fine and just reports a version number of 0.0.0.0. When I manually look at the properties of a real EXE and my fake EXE I see that File version and Product version both exist as properties, but are empty. I'm not casting the version value to [version] or anything, so it seems like Windows itself inserts a value of 0.0.0.0 when it's null, which... sucks. Is this something I can actually depend on; that no REAL executable will ever have a value of 0.0.0.0 for Version, and report that as a bad file accordingly? Or is 0.0.0.0 a valid version number that someone might actually use?

0.0.0.0 is technically a valid version number, but I'd say it's quite unlikely that an executable uses it explicitly.
Pragmatically speaking, you can therefore infer from the presence of this version number that a given executable contains no embedded version resource.
$hasVersionResource = (Get-Command some.exe).Version.ToString() -ne '0.0.0.0'
However, this aspect is separate from whether a given file is a valid (binary) executable, i.e. whether it can actually run: binaries do not require this resource in order to execute.

Related

Possible to use commands provided by a recently installed program without restarting cmd/powershell?

I'm working on a script that automatically installs software. One of the programs to be installed includes its own command line commands and sub-commands when installed.
The goal is to use the program's provided commands to perform an action after its installation.
But running the command right after the program's installation I'm greeted by:
" is not recognized as an internal or external command , operable program or batch file"
If I open a new Powershell or cmd window the command is available in that instance.
What is the easiest way to to grant the script access to the commands?
Bender the Greatest's helpful answer explains the problem and shows you how to modify the $env:PATH variable in-session by manually appending a new directory path.
While that is a pragmatic solution, it requires that you know the specific directory path of the recently installed program.
If you don't - or you just want a generic solution that doesn't require you to hard-code paths - you can refresh the value of $env:PATH (the PATH environment variable) from the registry, via the [Environment]::GetEnvironmentVariable() .NET API method:
$env:PATH = [Environment]::GetEnvironmentVariable('Path', 'Machine'),
[Environment]::GetEnvironmentVariable('Path', 'User') -join ';'
This updates $env:PATH in-session to the same value that future sessions will see.
Note how the machine-level value (list of directories) takes precedence over the user-level one, due to coming first in the composite value.
Note:
If you happen to have made in-session-only $env:PATH modifications before calling the above, these modifications are lost.
If applicable, this includes modifications made by your $PROFILE file.
Hypothetically, other processes could have made additional modifications to the persistent Path variable definitions as well since your session started, which the call above will pick up too (as will future sessions).
This is because the PATH environment variable gets updated, but existing processes don't see that update unless they specifically query the registry for the live value of the update the PATH environment variable, then update PATH within its own process. If you need to continue in the same process, the workaround is to add the installation location to the PATH variable yourself after the program has been installed:
Note: I don't recommend updating the live value from the registry instead of the below in most cases. Other processes can modify that value, not just your own. It can introduce unnecessary risk, whereas appending only what you know should have changed is a more pragmatic approach. In addition, it adds code complexity for a case that often doesn't need to be generalized to that point.
# This will update the PATH variable for the current process
$env:PATH += ";C:\Path\To\New\Program\Folder;"

NSIS nsProcess Plugin: Always returns "process not running"

Context
We are using NSIS 3.05 with Unicode true (this is important later).
We need to check if a certain process is running, let's call it "processToFind.exe".
In order to do that, we have been using nsProcess Plugin, which is set up correctly, found and integrated just fine.
We include Plugins from our git repository like this:
!addincludedir "C:\pathToRepo\NSIS\Include"
!addplugindir "C:\pathToRepo\NSIS\Plugins"
where pathToRepo is of course a valid path. We also tried using the default Plugin Directories (NSIS-Dir\Plugins\x86-unicode) to no avail (see below).
Documentation says, nsProcess (v 1.6) does suppport unicode. That's why we chose to use it.
NSIS UNICODE support (just rename nsProcessW.dll into nsProcess.dll)
When setting Unicode false or leaving the setting out (so default is ansi), it is working fine, too. ( = running processes found, not running processes not found )
The Installer is 32 bit, we are running on 64 bit Windows 10 machines.
Code
${nsProcess::FindProcess} "procexp.exe" $R0
MessageBox MB_OK "procexp: [$R0]"
which is defined in nsProcess.nsh (provided by plugin, not own code)
!define nsProcess::FindProcess `!insertmacro nsProcess::FindProcess`
!macro nsProcess::FindProcess _FILE _ERR
nsProcess::_FindProcess /NOUNLOAD `${_FILE}`
Pop ${_ERR}
!macroend
Problem
When having set Unicode true , nsProcess will always return 603 ("Process was not currently running").
That's the same, regardless if we try to find 32-bit or 64-bit processes.
That would be expected for 64-bit processes (they cannot be found from 32-bit installers, which is ok for us).
But I do expect it to find 32-bit processes.
Alternatives already explored:
Going through the list found at Check whether your application is running ...
Processes Plugin : Seems outdated, only sourcecode found.
"FindProcess.nsh" : Naming collision, didn't work, neither. Same symptoms.
DDE Server / Win32 Sync / Registry: Not an option.
"tasklist" command: Same symptoms. When executed in cmd, it works but not from installer.
nsExec::ExecToStack '"%SystemRoot%\System32\tasklist" /NH /FI "IMAGENAME eq ${processName}" | "%SystemRoot%\System32\find" /I "${processName}"' always returns "error". (* it's clear now why, see edit below)
"FindProcDLL" Plugin : skipped because
As of NSIS 2.46 this plugin no longer works...
Seemingly related Stackoverflow Questions explored:
NSIS : NsProcess UnExpected Output
Solution was to remove Unicode=true, which I cannot do.
NSIS- FindProc always returns 1
Uses FindProcDLL
NSIS - check if process exists (nsProcess not working)
Error was "Plugin not found" , which we do not have.
I am sure, we are making some "stupid" mistake since I cannot bring myself to believing we are the only ones with that requirement. So, any hints, suggestions and alternatives that are not listed above (or corrections to the above) are welcomed.
Edit
We totally messed up the tasklist call. As #Anders pointed out in comment: nsExec does not support pipes and on top of that, the syntax was also messed up.
Does official example work for you? It works on my machine.
Try this:
0) Delete all nsProcess.dll files (in NSIS, in your include folders, everywhere)
1) Remove line !addplugindir "C:\pathToRepo\NSIS\Plugins" from your script to use plugins in NSIS directories
2) Copy file nsProcessW.dll into **c:\Program Files (x86)\NSIS\Plugins\x86-unicode**
3) Rename file c:\Program Files (x86)\NSIS\Plugins\x86-unicode\nsProcessW.dll -> nsProcess.dll
4) Compile your script with Unicode true
I believe there is some file mismatch. To understand NSIS plugins structure see NSIS - check if process exists (nsProcess not working) .
I'm still using ANSI because I'm using some other plugins that don't have a Unicode variant, so nsProcess works for me, and I'm not sure how to answer your main question.
However, re: the tasklist command alternative you listed, the syntax isn't quite right. You're missing a closing quote after "IMAGENAME eq ${processName}["] and an opening quote before ["]${processName}" in the pipe to find.exe.
Also FYI note that if you use %SystemRoot%\System32\, a 32-bit process will be redirected to C:\Windows\SysWOW64\, and some programs have no 32-bit equivalent (e.g., pnputil). In this case, it doesn't really matter, but in any event to get around this, you should use $WINDIR\SysNative instead. You can also use ${DisableX64FSRedirection} from x64.nsh, but there are apparently some potential pitfalls there.
EDIT: Ah yes, and there's the issue with pipe and ExecToStack mentioned by Anders in the comments to the original question, requiring the call to be prefixed with cmd.exe /C

PowerShell: Start-Process Firefox, how do he know the path?

When I call the following code:
Start-Process Firefox
Then the PowerShell opens the browser. I can do that with several other programs and it works. My question is: How does the PowerShell know which program to open if I type Firefox? I mean, Im not using a concrete Path or something ...
I though it has something to do with the environment variables ... But I cannot find any variable there which is called Firefox ... How can he know?
I traced two halves of it, but I can't make them meet in the middle.
Process Monitor shows it checks the PATHs, and eventually checks HKLM\Software\Microsoft\Windows\CurrentVersion\App Paths\firefox.exe so that's my answer to how it finds the install location, and then runs it.
That registry key is for Application Registration which says:
When the ShellExecuteEx function is called with the name of an executable file in its lpFile parameter, there are several places where the function looks for the file. We recommend registering your application in the App Paths registry subkey.
The file is sought in the following locations:
The current working directory.
The Windows directory only (no subdirectories are searched).
The Windows\System32 directory.
Directories listed in the PATH environment variable.
Recommended: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths
That implies PowerShell calls the Windows ShellExecuteEx function, which finds FireFox as a registered application, or it tries the same kind of searching itself internally.
Going the other way to try and confirm that, the Start-Process cmdlet has a parameter set called UseShellExecute. The 'Notes' of that help says:
This cmdlet is implemented by using the Start method of the System.Diagnostics.Process class. For more information about this method, see Process.Start Method
Trying to trace through the source code on GitHub:
Here is the PowerShell source code for Start-Process.
Here, at this line it tries to look up the $FilePath parameter with CommandDiscovery.LookupCommandInfo.
Here it checks else if (ParameterSetName.Equals("UseShellExecute"))
Then Here is the .Start() function which either starts it with ShellExecute or Process.Start()
OK, not sure if ShellExecute and ShellExecuteEx behave the same, but it could be PS calling Windows, which is doing the search for "FireFox".
That CommandSearcher.LookupCommandInfo comes in here and follows to TryNormalSearch() which is implemented here and immediately starts a CommandSearcher which has a state machine for the things it will search
SearchState.SearchingAliases
Functions
CmdLets
SearchingBuiltinScripts
StartSearchingForExternalCommands
PowerShellPathResolution
QualifiedFileSystemPath
and there I get lost. I can't follow it any further right now.
Either it shortcuts straight to Windows doing the lookup
Or the PowerShell CommandSearcher does the same search somehow
Or the PowerShell CommandSearcher in some way runs out of searching, and the whole thing falls back to asking Windows search.
The fact that Process Monitor only logs one query in each PATH folder for "firefox.*" and then goes to the registry key suggests it's not doing this one, or I'd expect many more lookups.
The fact that it logs one query for "get-firefox.*" in each PATH folder suggests it is PowerShell's command searcher doing the lookup and not Windows.
Hmm.
Using Process Monitor I was able to trace the PowerShell.
It first searches the $env:path variable, then the $profile variable.
In my case firefox wasn't found and then it searches through a whole lot in the Registry and somehow finds it.
It might have something to do with how firefox is installed on the system.

Using the --glob_ignores flag of SVN_Load_Dirs.PL

I am attempting to use the SVN_Load_Dirs.PL script file (https://svn.apache.org/repos/asf/subversion/trunk/contrib/client-side/svn_load_dirs/) to attempt to merge a platform drop.
However, I can't get the --glob_ignores flag to behave as I'd expect, and I know so little perl that I can't dig into the script to understand why. The format I am using is:
--glob_ignores=*.jazzignore
Where I want to ignore all .jazzignore files (although I am fine with anything with "jazzignore" in either the extension or name being ignored. I've looked for examples but can't find any actual usage of this flag anywhere. What I am looking for is a way to ignore all .jazzignore files and a few entire directories (like jazz5 for an example)
I assumed the flag would then be --glob_ignores="*.jazzignore *.jazz5" but that doesn't appear to be working.
It turns out that the script was failing silently because I was running it from a windows cmd (and therefore never getting to the flag option). Apparently there are some issues running it this way and it was designed to be run from a linux command line. After switching it works perfectly.

How to SET fileinfo version to a PS1 file with Powershell

I have a PowerShell script named myscript.ps1 on a remote server.
I would like to know what is the version of this file.
Unfortunately this command gives me nothing :
(Get-Item "C:\myscript.ps1").VersionInfo.FileVersion
My question is : is there a way to add some information regarding the version of the script or else ? If yes, how please ?
My end goal is to check if the running script is the latest version otherwise download latest version on remote server and execute.
Thank you all.
I'm not sure you're going to find that information there unless it was set. I usually see that info in things like DLLs.
If it were me, and I was looking to see if a file was different (a script or otherwise) I would use the Get-FileHash commandlet instead.
You can not set FileVersionInfo in .Net, so you will always get a null value when you check the FileVersionInfo on your PowerShell script. What you may want to do instead is to check the LastWriteTime property to see if the file on the server is newer than what you have locally.