Powershell Invoke-Expressions pauses - powershell

I wrote a Powershell script that uses Steam's command line tool to login and check for updates for a community server I am running. See below:
$steamcmdFolder = 'C:\download\steam'
$steamcmdExec = $steamcmdFolder+"\steamcmd.exe"
$forceinstall = 'force_install_dir'+$steamcmdFolder
$appupdate = 'app_update 258550'
$cmdOutput = "$steamcmdExec +login anonymous"
do {
Write-Host Checking for an update....
Invoke-Expression $cmdOutput
Invoke-expression $forceinstall
Invoke-expression $appupdate
}
while ($Update = 1)
The Invoke-Expression lines are individual command-line statements I want executed in the order I have them. For some reason, the first Invoke-Expression works fine but the others do not -- everything just stops. I can type in the value of $forceinstall on the PowerShell command-line and it works as expected. But why can't I do this using PowerShell? Any suggestions are welcome!

If you convert the other two lines down to what they are, it seems like they are not real commands.
#Invoke-expression $forceinstall
Invoke-Expression "force_install_dirC:\download\steam"
#Invoke-expression $appupdate
Invoke-Expression "app_update 258550"
Looking into the SteamCMD documents, it appears that you might want to change it to be a single line command.
Invoke-Expression "steamcmd +login anonymous +force_install_dir C:\download\steam +app_update 258550 +quit"

Related

How do I have to change PowerShell variables code so that I can run it via CMD?

How do I have to change PowerShell code so that I can run it via CMD?
I came up with the following code:
$text_auslesen = Get-Content $env:APPDATA\BIOS-Benchmark\PowerShell-Protokoll-Auswertung.txt
$text_auslesen.Replace("Count :","") > $env:APPDATA\BIOS-Benchmark\Count_only.txt
$text_auslesen = Get-Content $env:APPDATA\BIOS-Benchmark\PowerShell-Protokoll-Auswertung.txt
$text_auslesen.Replace("Average :","") > $env:APPDATA\BIOS-Benchmark\Durchschnitt_only.txt
If I copy and paste it completely into a powershell, it can run. But now I have to put the code next to other code in a batch file. How do I have to adjust the code so that the cmd.exe executes the whole thing?
I suspect setting the variables via Powershell code is problematic here.
Unfortunately, a PS1 file is out of the question for my project.
To execute PowerShell commands from a batch file / cmd.exe, you need to create a PowerShell child process, using the PowerShell CLI (powershell.exe for Windows PowerShell, pwsh for PowerShell (Core) 7+) and pass the command(s) to the -Command (-c) parameter.
However, batch-file syntax does not support multi-line strings, so you have two options (the examples use two simple sample commands):
Pass all commands as a double-quoted, single-line string:
powershell.exe -Command "Get-Date; Write-Output hello > test.txt"
Do not use quoting, which allows you to use cmd.exe's line continuations, by placing ^ at the end of each line.
powershell.exe -Command Get-Date;^
Write-Output hello ^> test.txt
Note:
In both cases multiple statements must be separated with ;, because ^ at the end of a batch-file line continues the string on the next line without a newline.
Especially with the unquoted solution, you need to carefully ^-escape individual characters that cmd.exe would otherwise interpret itself, such as & and >
See this answer for detailed guidance.
Powershell -c executes PowerShell commands. You can do this from cmd, however, it looks like it needs to be run as administrator.
PowerShell -c "$text_auslesen = Get-Content $env:APPDATA\BIOS-Benchmark\PowerShell-Protokoll-Auswertung.txt;
$text_auslesen.Replace('Count :','') > $env:APPDATA\BIOS-Benchmark\Count_only.txt;
$text_auslesen = Get-Content $env:APPDATA\BIOS-Benchmark\PowerShell-Protokoll-Auswertung.txt;
$text_auslesen.Replace('Average :','') > $env:APPDATA\BIOS-Benchmark\Durchschnitt_only.txt"
It is possible to execute the PowerShell code in a batch file, but technically what you are doing is pulling a copy of it out and executing it someplace else. Here are 3 methods that I know of.
mklement0's answer addresses executing a copy of it that is passed as a parameter to PowerShell.
You could build a ps1 file from CMD, and then execute that ps1 file by passing it as a parameter to PowerShell.
And the method I've worked with the most is to pass specially designed PowerShell code to PowerShell that, when it runs, will load all, or part, of the current CMD file into memory and execute it there as a ScriptBlock. I have tried loading parts of the current CMD file, but my experience has been that this gets too complicated and I just stick with loading the entire current CMD file.
That last method is what I'm presenting here. The trick is to make the batch/CMD portion of the script look like a comment that is ignored by PowerShell, but still runs without throwing error messages in CMD. I'm not sure where I first found this trick, but it goes like this:
First, place <# : at the start of script. PowerShell sees this as the start of a comment, but CMD seems to ignore this line. I think CMD is trying to redirect < the contents of a non-existing file : to a non-existing command. But what does CMD do with the #? It works, and that's the important thing.
Place your batch code in lines following the <# :.
You end the batch/CMD part with a GOTO :EOF.
You then end the PowerShell comment with #>, but visually I find it easier to find <#~#>, which does the same job.
The rest of the file is your PowerShell code.
This version treats the PowerShell code as a function with defined parameters. The batch part builds %ARGS% and passes, with double quotes intact, to a PowerShell ScriptBlock that in turn is wrapped in another ScriptBlock. The PowerShell function is called twice with the same SourceFile parameter, but different DestinationFile and TextToRemove parameters. Perhaps there is a simpler way to reliably pass double quotes " in arguments passed to a ScriptBlock from batch, but this is the method I got working.
<# :
#ECHO OFF
SET f0=%~f0
SET SourceFile=%APPDATA%\BIOS-Benchmark\PowerShell-Protokoll-Auswertung.txt
SET ARGS="%SourceFile%" "%APPDATA%\BIOS-Benchmark\Count_only.txt" "Count :"
PowerShell -NoProfile -Command ".([scriptblock]::Create('.([scriptblock]::Create((get-content -raw $Env:f0))) ' + $Env:ARGS))"
SET ARGS="%SourceFile%" "%APPDATA%\BIOS-Benchmark\Durchschnitt_only.txt" "Average :"
PowerShell -NoProfile -Command ".([scriptblock]::Create('.([scriptblock]::Create((get-content -raw $Env:f0))) ' + $Env:ARGS))"
GOTO :EOF
<#~#>
param (
[Parameter(Mandatory = $true, Position = 0)]
[string]$SourceFile,
[Parameter(Mandatory = $true, Position = 1)]
[string]$DestinationFile,
[Parameter(Mandatory = $true, Position = 2)]
[string]$TextToRemove
)
(Get-Content $SourceFile).Replace($TextToRemove, '') > $DestinationFile
This script passes a single parameter that, in PowerShell, is used by the Switch command to decide which section of PowerShell you intend on executing. Since we are not passing double quotes " in the args, the PowerShell lines can be greatly simplified. Information could still be passed to PowerShell by defining environmental variables in batch and reading them in PowerShell.
<# :
#ECHO OFF
SET f0=%~f0
PowerShell -NoProfile -Command .([scriptblock]::Create((get-content -raw $Env:f0))) Script1
PowerShell -NoProfile -Command .([scriptblock]::Create((get-content -raw $Env:f0))) Script2
GOTO :EOF
<#~#>
switch ($args[0]) {
'Script1' {
(Get-Content $env:APPDATA\BIOS-Benchmark\PowerShell-Protokoll-Auswertung.txt).Replace("Count :", '') > $env:APPDATA\BIOS-Benchmark\Count_only.txt
break
}
'Script2' {
(Get-Content $env:APPDATA\BIOS-Benchmark\PowerShell-Protokoll-Auswertung.txt).Replace("Average :", '') > $env:APPDATA\BIOS-Benchmark\Durchschnitt_only.txt
break
}
default {}
}
The -c parameter is intended to solve this scenario.
https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_pwsh?view=powershell-7.2#-command---c
If possible, it would be more efficient to invoke PowerShell\Pwsh directly rather than using a cmd wrapper.

Run Powershell script from inside other Powershell script with dynamic redirection to file

I have been struggling with this problem and researching around but can't get a solution
My problem: I need to run a Powershell script from inside another Powershell script and redirect the output stream to a file. So far so good.
The real issue comes when I need to control the amount of logging through a variable (e.g. write only errors or only error + warning + success output streams).
I can get around it by hard-coding the command as in:
Powershell -File "\path\myscript.ps1" 2>&1> $logFilePathAndName
However, I want to give the user a couple of options for the redirect operator and want to avoid hardcoding each one of them. For that, I was thinking to just code something similar to :
$logStreams = "2>&1>"
Powershell -File "\path\myscript.ps1" $logStreams $logFilePathAndName
The last command does run my script (myscript.ps1 has no input params) but it does not write anything to the file at $logFilePathAndName.
I tried various syntax with Invoke-Command, Invoke-Expression, the call operator and Powershell -Command with no luck.
Looked at this post, had several tries but I can't just get it to work.
For example this runs my script but does not write anything to the output log:
$logStreams = "2>&1>"
$command = '"C:\myscript.ps1" $_logStreams "C:\outputlog.txt"'
iex "& $command"
Is there a way to pass a variable string for the redirect operator OR run a string containing the entire command with a variable interpolated for the output redirector ?
Your last bit there is very close, but I'm not sure why you have the underscore in there, and you need to escape your dollar sign, and close the entire thing in double quotes to cause string extrapolation.
$logStreams = "2>&1>"
$command = "'C:\myscript.ps1' $logStreams 'C:\outputlog.txt'"
iex "& $command"
I just tested that locally and it works fine.

Powershell - Run external powershell script and capture output - Can't pass parameters

I have a problem running a powershell script from within another powershell script, passing parameters and capturing the output. I have tried using the ampersand operator, calling it via powershell.exe -Command but nothing seems to work.
What seems to work is using fixed parameter and values stored in a variable like this C:\path\to\script.ps1 -arg1 $value.
This may present a solution if nothing else works, but I would like to run the command similar to this & $pathToScript $params 2>&1 (the 2>&1is for capturing error output as well as standard).
Sometimes the construct prints just the path to the script,
sometimes it says Cannot run file in the middle of pipeline and sometimes it complains about it cannot find the mentioned script file (I sometimes have spaces in my path, but I thought quoting it would suffice: quoting was done like this $path = "`"C:\path\with space\to\script.ps1`"").
This is the simplified function I want to use this in:
Function captureScriptOutput
{
#the function receives the script path and parameters
param($path, $params)
#this works if no params are passed, but I need params!
$output = & $path $params 2>&1 | Out-String
}
I solved the problem with the help of a colleague.
We went a little indirection and included a cd into the respective directory and ran the command afterwards. This works like a charm.
Solution source code:
Function captureScriptOutput
{
param($fileName, $params)
cd "C:\into\path with\space"
$output = & .\$fileName $params 2>&1 | Out-String
}
This works and even captures the error output, I hope some other folks encountering this kind of problem can use this to fix their problems.
Cheerioh and thanks for reply!
Try with invoke-expression but you need test how many quote needed
Invoke-expression "$path $param"

Call a PowerShell script in a new, clean PowerShell instance (from within another script)

I have many scripts. After making changes, I like to run them all to see if I broke anything. I wrote a script to loop through each, running it on fresh data.
Inside my loop I'm currently running powershell.exe -command <path to script>. I don't know if that's the best way to do this, or if the two instances are totally separate from each other.
What's the preferred way to run a script in a clean instance of PowerShell? Or should I be saying "session"?
Using powershell.exe seems to be a good approach but with its pros and cons, of course.
Pros:
Each script is invoked in a separate clean session.
Even crashes do not stop the whole testing process.
Cons:
Invoking powershell.exe is somewhat slow.
Testing depends on exit codes but 0 does not always mean success.
None of the cons is mentioned is a question as a potential problem.
The demo script is below. It has been tested with PS v2 and v3. Script names
may include special characters like spaces, apostrophes, brackets, backticks,
dollars. One mentioned in comments requirement is ability to get script paths
in their code. With the proposed approach scripts can get their own path as
$MyInvocation.MyCommand.Path
# make a script list, use the full paths or explicit relative paths
$scripts = #(
'.\test1.ps1' # good name
'.\test 2.ps1' # with a space
".\test '3'.ps1" # with apostrophes
".\test [4].ps1" # with brackets
'.\test `5`.ps1' # with backticks
'.\test $6.ps1' # with a dollar
'.\test ''3'' [4] `5` $6.ps1' # all specials
)
# process each script in the list
foreach($script in $scripts) {
# make a command; mind &, ' around the path, and escaping '
$command = "& '" + $script.Replace("'", "''") + "'"
# invoke the command, i.e. the script in a separate process
powershell.exe -command $command
# check for the exit code (assuming 0 is for success)
if ($LastExitCode) {
# in this demo just write a warning
Write-Warning "Script $script failed."
}
else {
Write-Host "Script $script succeeded."
}
}
If you're on PowerShell 2.0 or higher, you can use jobs to do this. Each job runs in a separate PowerShell process e.g.:
$scripts = ".\script1.ps1", ".\script2.ps1"
$jobs = #()
foreach ($script in $scripts)
{
$jobs += Start-Job -FilePath $script
}
Wait-Job $jobs
foreach ($job in $jobs)
{
"*" * 60
"Status of '$($job.Command)' is $($job.State)"
"Script output:"
Receive-Job $job
}
Also, check out the PowerShell Community Extensions. It has a Test-Script command that can detect syntax errors in a script file. Of course, it won't catch runtime errors.
One tip for PowerShell V3 users: we (the PowerShell team) added a new API on the Runspace class called ResetRunspace(). This API resets the global variable table back to the initial state for that runspace (as well as cleaning up a few other things). What it doesn't do is clean out function definitions, types and format files or unload modules. This allows the API to be much faster. Also note that the Runspace has to have been created using an InitialSessionState object, not a RunspaceConfiguration instance. ResetRunspace() was added as part of the Workflow feature in V3 to support parallel execution efficiently in a script.
The two instances are totally separate, because they are two different processes. Generally, it is not the most efficient way to start a Powershell process for every script run. Depending on the number of scripts and how often you re-run them, it may be affecting your overall performance. If it's not, I would leave everything AS IS.
Another option would be to run in the same runspace (this is a correct word for it), but clean everything up every time. See this answer for a way to do it. Or use below extract:
$sysvars = get-variable | select -Expand name
function remove-uservars {
get-variable |
where {$sysvars -notcontains $_.name} |
remove-variable
}

PowerShell 2.0 - Running scripts for the command line call vs. from the ISE

After writing deployment scripts from within the ISE, we need our continuous integration (CI) server to be able to run them automatically, i.e. from the command line or via a batch file.
I have noticed some significant differences between the following calls:
powershell.exe -File Script.ps1
powershell.exe -Command "& '.\Script.ps1'"
powershell.exe .\Script.ps1
Some simple examples:
When using -File, errors are handled in the exact same way as the ISE.
The other two calls seem to ignore the $ErrorActionPreference variable, and do not catch Write-Error in try/catch blocks.
When using pSake:
The last two calls work perfectly
Using the ISE or the -File parameter will fail with the following error:
The variable '$script:context' cannot be retrieved because it has not been set
What are the implications of each syntax, and why they are behaving differently? I would ideally like to find a syntax that works all the time and behaves like the ISE.
Not an answer, just a note.
I searched for explanation of -file parameter. Most sources say only "Execute a script file.". At http://technet.microsoft.com/en-us/library/dd315276.aspx I read
Runs the specified script in the local scope ("dot-sourced"), so that the functions
and variables that the script creates are available in the current session. Enter
the script file path and any parameters.
After that I tried to call this:
powershell -command ". c:\temp\aa\script.ps1"
powershell -file c:\temp\aa\script.ps1
powershell -command "& c:\temp\aa\script.ps1"
Note that first two stop after Get-Foo, but the last one doesn't.
The problem I describe above is related to modules -- if you define Get-Foo inside script.ps1, all the 3 calls I described stop after call to Get-Foo.
Just try to define it inside the script.ps1 or dotsource the file with Get-Foo and check it. There is a chance it will work :)
Here is a concrete example of the behaviour I described.
MyModule.psm1
function Get-Foo
{
Write-Error 'Failed'
}
Script.ps1
$ErrorActionPreference = 'Stop'
$currentFolder = (Split-Path $MyInvocation.MyCommand.Path)
Import-Module $currentFolder\MyModule.psm1
try
{
Get-Foo
Write-Host "Success"
}
catch
{
"Error occurred"
}
Running Script.ps1:
From the ISE, or with the -File parameter
will output "Error occurred" and stop
From the command line without the -File parameter
will output "Failed" followed by "Success" (i.e. not caught)