Not critical but gave me a headache...
I wanted the output of write-verbose into a variable for documentation/debugging.
Its nice, powershel has an own parameter for the output of commands (see help about_commonparameters).
But whats not stated in the help is: what write-* output goes to what variable
so i tried and tried and found out:
write-warning writes just to -warningVariable
write-error writes just to -errorVariable
write-output writes just to -outVariable
BUT where goes the write-verbose output?
The help says
This cmdlet supports the common parameters: -Verbose, -Debug, -ErrorAction, -ErrorVariable, -OutBuffer, and -OutVariable.
For Example:
write-verbose "test" -verbose -outvariable $a
Nothings in $a
(same for write-warning "test" -ev $b... nothing)
any ideas? thanks in advance
Write-Verbose has no "output" to write to an OutVariable. It does write things to the verbose stream, though.
OutVariable contains all objects that were output to the output stream.
One option:
$VerbosePreference = 'continue'
Write-Verbose ($a = 'foo')
$a
VERBOSE: foo
foo
If you want just the output of Write-Verbose in a variable you could use redirection:
$var = Write-Verbose 'something' 4>&1
That will merge the verbose stream with the success output stream, which can be captured in a variable.
This won't work if you need regular and verbose output in separate variables, though. As far as I'm aware you must redirect verbose output to a file and read the file into a variable for that.
PS C:\> function Foo { Write-Verbose 'foo'; Write-Output 'bar' }
PS C:\> $VerbosePreference = 'Continue'
PS C:\> Foo
VERBOSE: foo
bar
PS C:\> $o = Foo 4>'C:\temp\verbose.txt'
PS C:\> $v = Get-Content 'C:\temp\verbose.txt'
PS C:\> $o
bar
PS C:\> $v
foo
Same goes for warnings, only that warnings go to stream number 3.
PS C:\> function Bar { Write-Warning 'foo'; Write-Output 'bar' }
PS C:\> $WarningPreference = 'Continue'
PS C:\> Bar
WARNING: foo
bar
PS C:\> $o = Bar 3>'C:\temp\warning.txt'
PS C:\> $w = Get-Content 'C:\temp\warning.txt'
PS C:\> $o
bar
PS C:\> $w
foo
Redirection of the warning, verbose, and debug streams was introduced with PowerShell version 3.
Related
I'm learning the powershell. Currently I have a tough requirement. I need to call an powershell script(ps1) in parallel from an powershell module(psm1). The ps1 task is like following
param(
[Parameter(Mandatory=$true)]
[String] $LogMsg,
[Parameter(Mandatory=$true)]
[String] $FilePath
)
Write-Output $LogMsg
$LogMsg | Out-File -FilePath $FilePath -Append
The FilePath is like "C:\Users\user\Documents\log\log1.log"
And in the psm1 file, I use the runspacepool to do async task. Like the following demo
$MaxRunspaces = 5
$RunspacePool = [runspacefactory]::CreateRunspacePool(1, $MaxRunspaces)
$RunspacePool.Open()
$Jobs = New-Object System.Collections.ArrayList
Write-Host $currentPath
Write-Host $lcmCommonPath
$Filenames = #("log1.log", "log2.log", "log3.log")
foreach ($File in $Filenames) {
Write-Host "Creating runspace for $File"
$PowerShell = [powershell]::Create()
$PowerShell.RunspacePool = $RunspacePool
$FilePath = -Join("C:\Users\user\Documents\log\",$File)
$PowerShell.AddScript("C:\Users\user\Documents\foo.ps1").AddArgument($FilePath) | Out-Null
$JobObj = New-Object -TypeName PSObject -Property #{
Runspace = $PowerShell.BeginInvoke()
PowerShell = $PowerShell
}
$Jobs.Add($JobObj) | Out-Null
}
But there are two serious problem.
Can't pass the parameters to ps1 file.
I just try to create the file path in the ps1 file side, it works and file created. But when I try to pass the argument from psm1 file. The files are not created. I also try to use script block and it can pass the parameters. But since my ps1 code is too large(The above is just part of it), using script block is unreal. I need a method to pass parameter to ps1 file.
Can't get write-host information in ps1 file while psm1 is still running
If the runspacepool has limitation for passing the parameters to ps1 file, is there any other solution to deal with the async task for powershell script? Thanks.
Can't pass the parameters to ps1 file.
Use AddParameter() instead of AddArgument() - this will allow you to bind the argument to a specific parameter by name:
$PowerShell.AddScript("C:\Users\user\Documents\foo.ps1").
AddParameter('FilePath', $FilePath).
AddParameter('LogMsg', 'Log Message goes here') | Out-Null
Can't get write-host information in ps1 file while psm1 is still running
Correct - you cannot get host output from a script not attached to the host application's default runspace - but if you're using PowerShell 5 or newer you can collect the resulting information from the $PowerShell instance and relay that if you want to:
# Register this event handler after creating `$PowerShell` but _before_ calling BeginInvoke()
Register-ObjectEvent -InputObject $PowerShell.Streams.Information -EventName DataAdded -SourceIdentifier 'WriteHostRecorded' -Action {
$recordIndex = $EventArgs.Index
$data = $PowerShell.Streams.Information[$recordIndex]
Write-Host "async task wrote '$data'"
}
I have some script to modify hosts. It's something like this:
#echo off
Powershell.exe -NoProfile -Command "& { $var = cat c:\...\hosts;
$var = $var -replace '....','....'
try {
Set-Content c:\...\hosts $var -ErrorAction Stop
} catch {
echo 'CAN`T WRITE'; pause; exit 2;
}
}"
exit $LASTEXITCODE
This is only an example, real script is more complex.
The problem is that sometimes script shows CAN'T WRITE error, but hosts file becomes empty, all the content is gone.
Any suggestions on how i can prevent losing file content on Set-Content error?
When you execute a statement in Try block, it is actually executed. Then if $var is $null, then the text file gets empty. And you see the error message using Catch block. Then you can save the content before, and if error occurs return the original file back in the Catch block:
#echo off
Powershell.exe -NoProfile -Command "& { $var = cat c:\...\hosts;
$oldvar = $var
$var = $var -replace '....','....'
try {
Set-Content c:\...\hosts $var -ErrorAction Stop
} catch {
echo 'CAN`T WRITE'; pause; exit 2;
$oldvar | Set-Content C:\...\hosts
New-Item "Backup.txt" -Type File -Value $oldvar
}
}"
exit $LASTEXITCODE
$oldvar will contain the the original content of the text file which can you use later. And to be more safe, i have added to write the content into a backup file (Backup.txt) if Writing again to the file fails.
Let's say I have a script:
write-host "Message.Status: Test Message Status";
I managed to run it in a separate process by doing:
powershell.exe -Command
{ write-host "Message.Status: Test Message Status"; }
The problem is I want to pass parameters to the script so that I can achieve something like this:
write-host "I am in main process"
powershell.exe -Command -ArgumentList "I","am","here"
{
write-host "I am in another process"
write-host "Message.Status: $($one) $($two) $($three)";
}
However -ArgumentList doesn't work here
I get:
powershell.exe : -ArgumentList : The term '-ArgumentList' is not recognized as the name of a cmdlet, function, script file, or operable
I need to run some part of PowerShell script file in a different process and I cannot use another file due to the fact that PowerShell script is uploaded to external system.
The -Command parameter is expecting a scriptblock in which you can define your parameters using a Param() block. Then use the -args parameter to pass in the arguments. Your only mistake was to put the -args after -command before you defined the scriptblock.
So this is how it works:
write-host "I am in main process $($pid)"
powershell.exe -Command {
Param(
$one,
$two,
$three
)
write-host "I am in process $($pid)"
write-host "Message.Status: $($one) $($two) $($three)";
} -args "I", "am", "here" | Out-Null
Output:
I am in main process 17900
I am in process 10284
Message.Status: I am here
You can use the -File parameter and follow it by the path to script. Any unnamed arguments which follows will be passed as script parameters. Something like below should do
powershell -File "C:\ScriptFolder\ScriptwithParameters.ps1" "ParameterOneValu" "valuetwo"
Ok so if you need another process entirely but not another file then your best bet is probably .NET runspaces. Basically wrap your code in a scriptblock
$SB = {
*Your Code*
}
Then set up a runspace like below, making sure to use the "UseNewThread" as the thread option. Note that $arg is whatever your argument to be passed to the script is
$newRunspace =[runspacefactory]::CreateRunspace()
$newRunspace.ApartmentState = "STA"
$newRunspace.ThreadOptions = "UseNewThread"
$newRunspace.Open()
$psCmd = [PowerShell]::Create().AddScript($SB).AddArgument($arg)
$psCmd.Runspace = $newRunspace
$data = $psCmd.BeginInvoke()
You'll likely need to tweak this if you need to get any data back from the runspace once it is complete but there are a few ways to do that(leave a comment if you need assistance). If you need synchronous execution rather than async then change .BeginInvoke() to .Invoke()
So should get you started, But it will require a few moving parts.
First we define a new function:
function Run-InNewProcess{
param([String] $code)
$code = "function Run{ $code }; Run $args"
$encoded = [Convert]::ToBase64String( [Text.Encoding]::Unicode.GetBytes($code))
start-process PowerShell.exe -argumentlist '-noExit','-encodedCommand',$encoded
}
This function will be what starts the new process. It uses the start-process cmdlet, The -Argumentlist is our arguments applied to the powershell.exe You can remove -noExit to make the new process close on completion or add other powershell flags, and flags on Start-Process to get the windows and behaviours tweaked to your requirements.
Next we define our script block:
$script = {
[CmdletBinding()]
Param (
[Parameter(Position=0)]
[string]$Arg1,
[Parameter(Position=1)]
[string]$Arg2)
write-host "I am in another process"
write-host "Message.Status: $($Arg1) $($Arg2)";
}
Here we define some parameters in the opening part of the block, They have a position and name, so for example any argument in position 0 will be in the variable $arg1 The rest of the code in the block is all executed in the new process.
Now we have defined the script block and the function to run it in a new process, All we have to do is call it:
Run-InNewProcess $script -Arg1 '"WHAT WHAT"' -Arg2 '"In the But"'
Copy past this code all in to your ISE and you will see it in action.
Start-Job will create a process for its scriptblock, and it's straightforward to pass arguments to it.
Write-Host "Process count before starting job: $((Get-Process |? { $_.ProcessName -imatch "powershell" }).Count)"
$job = Start-Job `
-ArgumentList "My argument!" `
-ScriptBlock {
param($arg)
Start-Sleep -Seconds 5;
Write-Host "All Done! Argument: $arg"
}
while ($job.State -ne "Completed")
{
Write-Host "Process count during job: $((Get-Process |? { $_.ProcessName -imatch "powershell" }).Count)"
Start-Sleep -Seconds 1
}
Receive-Job $job -AutoRemoveJob -Wait
Write-Host "Process count after job: $((Get-Process |? { $_.ProcessName -imatch "powershell" }).Count)"
I've got some problem. I've written script in powershell to run batch file and save stderror and stdout to files (stdout: stdout.txt; stderr: stderr.txt and merged stdout and stderr: AllOutput.txt
test.ps1:
$allOutput = & C:\foo.bat 2>&1
$stderr = $allOutput | ?{ $_ -is [System.Management.Automation.ErrorRecord] }
$stdout = $allOutput | ?{ $_ -isnot [System.Management.Automation.ErrorRecord] }
Write-Host $allOutput
$allOutput | Out-File AllOutput.txt
$stdout | Out-File StdOut.txt
$stderr | Out-File StdErr.txt
The foo.bat file execute some code and bar.bat script:
dir
echo test
c:\bar.bat
echo endFoo
The bar.bat file execute this exaple code:
echo test
cd DDDDDD #not exists to get error
cd EEEEEE #not exists to get error
echo endBar
When I run test.ps1 directly on server I get AllOutput.txt with proper order - when on stderr is an error I get it after command. But when I start it on remote server by Invoke-Command -computerName serverName -File C:\test.ps1 or by Invoke-Command -computerName serverNAme -File \\serverPath\test3.ps1 I get output in wrong order - sometimes two errors from stderr in a row, sometime at the end of the file.
How can I execute it or rewrite in right way?
Is it possible to redirect stdout from an external program to a variable and stderr from external programs to another variable in one run?
For example:
$global:ERRORS = #();
$global:PROGERR = #();
function test() {
# Can we redirect errors to $PROGERR here, leaving stdout for $OUTPUT?
$OUTPUT = (& myprogram.exe 'argv[0]', 'argv[1]');
if ( $OUTPUT | select-string -Pattern "foo" ) {
# do stuff
} else {
$global:ERRORS += "test(): oh noes! 'foo' missing!";
}
}
test;
if ( #($global:ERRORS).length -gt 0 ) {
Write-Host "Script specific error occurred";
foreach ( $err in $global:ERRORS ) {
$host.ui.WriteErrorLine("err: $err");
}
} else {
Write-Host "Script ran fine!";
}
if ( #($global:PROGERR).length -gt 0 ) {
# do stuff
} else {
Write-Host "External program ran fine!";
}
A dull example however I am wondering if that is possible?
One option is to combine the output of stdout and stderr into a single stream, then filter.
Data from stdout will be strings, while stderr produces System.Management.Automation.ErrorRecord objects.
$allOutput = & myprogram.exe 2>&1
$stderr = $allOutput | ?{ $_ -is [System.Management.Automation.ErrorRecord] }
$stdout = $allOutput | ?{ $_ -isnot [System.Management.Automation.ErrorRecord] }
The easiest way to do this is to use a file for the stderr output, e.g.:
$output = & myprogram.exe 'argv[0]', 'argv[1]' 2>stderr.txt
$err = get-content stderr.txt
if ($LastExitCode -ne 0) { ... handle error ... }
I would also use $LastExitCode to check for errors from native console EXE files.
You should be using Start-Process with -RedirectStandardError -RedirectStandardOutput options. This other post has a great example of how to do this (sampled from that post below):
$pinfo = New-Object System.Diagnostics.ProcessStartInfo
$pinfo.FileName = "ping.exe"
$pinfo.RedirectStandardError = $true
$pinfo.RedirectStandardOutput = $true
$pinfo.UseShellExecute = $false
$pinfo.Arguments = "localhost"
$p = New-Object System.Diagnostics.Process
$p.StartInfo = $pinfo
$p.Start() | Out-Null
$p.WaitForExit()
$stdout = $p.StandardOutput.ReadToEnd()
$stderr = $p.StandardError.ReadToEnd()
Write-Host "stdout: $stdout"
Write-Host "stderr: $stderr"
Write-Host "exit code: " + $p.ExitCode
This is also an alternative that I have used to redirect stdout and stderr of a command line while still showing the output during PowerShell execution:
$command = "myexecutable.exe my command line params"
Invoke-Expression $command -OutVariable output -ErrorVariable errors
Write-Host "STDOUT"
Write-Host $output
Write-Host "STDERR"
Write-Host $errors
It is just another possibility to supplement what was already given.
Keep in mind this may not always work depending upon how the script is invoked. I have had problems with -OutVariable and -ErrorVariable when invoked from a standard command line rather than a PowerShell command line like this:
PowerShell -File ".\FileName.ps1"
An alternative that seems to work under most circumstances is this:
$stdOutAndError = Invoke-Expression "$command 2>&1"
Unfortunately, you will lose output to the command line during execution of the script and would have to Write-Host $stdOutAndError after the command returns to make it "a part of the record" (like a part of a Jenkins batch file run). And unfortunately it doesn't separate stdout and stderr.
In case you want to get any from a PowerShell script and to pass a function name followed by any arguments you can use dot sourcing to call the function name and its parameters.
Then using part of James answer to get the $output or the $errors.
The .ps1 file is called W:\Path With Spaces\Get-Something.ps1 with a function inside named Get-It and a parameter FilePath.
Both the paths are wrapped in quotes to prevent spaces in the paths breaking the command.
$command = '. "C:\Path Spaces\Get-Something.ps1"; Get-It -FilePath "W:\Apps\settings.json"'
Invoke-Expression $command -OutVariable output -ErrorVariable errors | Out-Null
# This will get its output.
$output
# This will output the errors.
$errors
Copied from my answer on how to capture both output and verbose information in different variables.
Using Where-Object(The alias is symbol ?) is an obvious method, but it's a bit too cumbersome. It needs a lot of code.
In this way, it will not only take longer time, but also increase the probability of error.
In fact, there is a more concise method that separate different streams to different variable in PowerShell(it came to me by accident).
# First, declare a method that outputs both streams at the same time.
function thisFunc {
[cmdletbinding()]
param()
Write-Output 'Output'
Write-Verbose 'Verbose'
}
# The separation is done in a single statement.Our goal has been achieved.
$VerboseStream = (thisFunc -Verbose | Tee-Object -Variable 'String' | Out-Null) 4>&1
Then we verify the contents of these two variables
$VerboseStream.getType().FullName
$String.getType().FullName
The following information should appear on the console:
PS> System.Management.Automation.VerboseRecord
System.String
'4>&1' means to redirect the verboseStream to the success stream, which can then be saved to a variable, of course you can change this number to any number between 2 and 5.
Separately, preserving formatting
cls
function GetAnsVal {
param([Parameter(Mandatory=$true, ValueFromPipeline=$true)][System.Object[]][AllowEmptyString()]$Output,
[Parameter(Mandatory=$false, ValueFromPipeline=$true)][System.String]$firstEncNew="UTF-8",
[Parameter(Mandatory=$false, ValueFromPipeline=$true)][System.String]$secondEncNew="CP866"
)
function ConvertTo-Encoding ([string]$From, [string]$To){#"UTF-8" "CP866" "ASCII" "windows-1251"
Begin{
$encFrom = [System.Text.Encoding]::GetEncoding($from)
$encTo = [System.Text.Encoding]::GetEncoding($to)
}
Process{
$Text=($_).ToString()
$bytes = $encTo.GetBytes($Text)
$bytes = [System.Text.Encoding]::Convert($encFrom, $encTo, $bytes)
$encTo.GetString($bytes)
}
}
$all = New-Object System.Collections.Generic.List[System.Object];
$exception = New-Object System.Collections.Generic.List[System.Object];
$stderr = New-Object System.Collections.Generic.List[System.Object];
$stdout = New-Object System.Collections.Generic.List[System.Object]
$i = 0;$Output | % {
if ($_ -ne $null){
if ($_.GetType().FullName -ne 'System.Management.Automation.ErrorRecord'){
if ($_.Exception.message -ne $null){$Temp=$_.Exception.message | ConvertTo-Encoding $firstEncNew $secondEncNew;$all.Add($Temp);$exception.Add($Temp)}
elseif ($_ -ne $null){$Temp=$_ | ConvertTo-Encoding $firstEncNew $secondEncNew;$all.Add($Temp);$stdout.Add($Temp)}
} else {
#if (MyNonTerminatingError.Exception is AccessDeniedException)
$Temp=$_.Exception.message | ConvertTo-Encoding $firstEncNew $secondEncNew;
$all.Add($Temp);$stderr.Add($Temp)
}
}
$i++
}
[hashtable]$return = #{}
$return.Meta0=$all;$return.Meta1=$exception;$return.Meta2=$stderr;$return.Meta3=$stdout;
return $return
}
Add-Type -AssemblyName System.Windows.Forms;
& C:\Windows\System32\curl.exe 'api.ipify.org/?format=plain' 2>&1 | set-variable Output;
$r = & GetAnsVal $Output
$Meta2=""
foreach ($el in $r.Meta2){
$Meta2+=$el
}
$Meta2=($Meta2 -split "[`r`n]") -join "`n"
$Meta2=($Meta2 -split "[`n]{2,}") -join "`n"
[Console]::Write("stderr:`n");
[Console]::Write($Meta2);
[Console]::Write("`n");
$Meta3=""
foreach ($el in $r.Meta3){
$Meta3+=$el
}
$Meta3=($Meta3 -split "[`r`n]") -join "`n"
$Meta3=($Meta3 -split "[`n]{2,}") -join "`n"
[Console]::Write("stdout:`n");
[Console]::Write($Meta3);
[Console]::Write("`n");