Related
I'd like to use a kinda analyzer which will install/import all the needed modules by the script before I run it on distant machine (which could not have it) ......
any idea ?
EDIT
Here's the case :
I'm on my dev machine, I'ved already installed lots of modules of all kind (dhcp, ntfs, remoting, register, etc.)
When I finally got my script (which is a function) to work, I can't be sure of what modules are used....
What I want is to write down, in the 'begin' section, the correct imports before I send my script on remote PCs; to be sure it's gonna run perfectly, you follow ?...
Is there a kinda a third party appplication which can scan my script and give me all needed modules ?
You could do something like this to get help in finding commands used and their source/module names. It's very unpolished, just trying to give the idea.
$scriptblock = {
Write-Host "Nothing here"
$files = Get-ChildItem c:\temp
Get-ADUser someuser
Test-NetConnection www.google.com
}
# Uncomment following lines and enter the path to your script file
# $scriptFile = "Path\to\some\scriptfile"
# $scriptblock = [scriptblock]::Create((Get-Content -raw -Path $scriptFile))
$ast = $scriptblock.Ast
$commands = $ast.FindAll( { $args[0] -is [System.Management.Automation.Language.CommandAst] }, $true)
$commandText = foreach ($command in $commands) {
$command.CommandElements[0].Extent.Text
}
$commandText |
Select-Object -Unique |
Sort-Object |
Select-Object #{
Label = "CommandName"
Expression = { $_ }
},
#{
Label = "Source"
Expression = {
(Get-Command $_).Source
}
}
Output
CommandName Source
----------- ------
Get-ADUser ActiveDirectory
Get-ChildItem Microsoft.PowerShell.Management
Test-NetConnection NetTCPIP
Write-Host Microsoft.PowerShell.Utility
Yeah, you could for example test if the module exists on that particular machine by trying to import it as follows
Try {
Import-Module dbaclone -ErrorAction stop
#ErrorAction required as failing to import is not a terminating action
} Catch {
Write-Verbose -Verbose "Failed to find dbaclone module - installing"
Install-Module dbaclone -AllowClobber -Force
Write-Verbose -Verbose "Installed!"
Import-Module dbaclone
}
I’ve the following PowerShell script which searches in a directory for PowerShell module). All found modules will be imported and stored in a list (using the -PassThru) option.
The scrip iterates over the imported modules and invokes a function defined in the module:
# Discover and import all modules
$modules = New-Object System.Collections.Generic.List[System.Management.Automation.PSModuleInfo]
$moduleFiles = Get-ChildItem -Recurse -Path "$PSScriptRoot\MyModules\" -Filter "Module.psm1"
foreach( $x in $moduleFiles ) {
$modules.Add( (Import-Module -Name $x.FullName -PassThru) )
}
# All configuration values
$config = #{
KeyA = "ValueA"
KeyB = "ValueB"
KeyC = "ValueC"
}
# Invoke 'FunctionDefinedInModule' of each module
foreach( $module in $modules ) {
# TODO: Check function 'FunctionDefinedInModule' exists in module '$module '
& $module FunctionDefinedInModule $config
}
Now I would like to first check if a function is defined in a module before it gets invoked.
How can such a check be implemented?
The reason for adding the check if to avoid the exception thrown when calling a function which doesn’t exists:
& : The term ‘FunctionDefinedInModule’ is not recognized as the name of a cmdlet, function, script file, or operable program
Get-Command can tell you this. You can even use module scope to be sure it comes from a specific module
get-command activedirectory\get-aduser -erroraction silentlycontinue
For example. Evaluate that in an if statement and you should be good to go.
Use Get-Command to check if a function currently exists
if (Get-Command 'FunctionDefinedInModule' -errorAction SilentlyContinue) {
"FunctionDefinedInModule exists"
}
If many functions need to be checked
try{
get-command -Name Get-MyFunction -ErrorAction Stop
get-command -Name Get-MyFunction2 -ErrorAction Stop
}
catch{
Write-host "Load Functions first prior to laod the current script"
}
I needed it so often that I wrote module for this.
Maybe try adding this function to your module?
function DoesFunctionExists {
param(
[string]$Function
)
$FunList = gci function:$Function -ErrorAction 'SilentlyContinue'
foreach ($FunItem in $FunList) {
if ($FunItem.Name -eq $Function) {
return $true
}
}
return $false
}
It is well known that Write-Host is evil.
In PowerShell 5, Write-Information is added and is considered to replace Write-Host.
But, really, which is better?
Write-Host is evil for it does not use pipeline, so the input message can't get reused.
But, what Write-Host do is just to show something in the console right? In what case shall we reuse the input?
Anyway, if we really want to reuse the input, why not just write something like this:
$foo = "Some message to be reused like saving to a file"
Write-Host $foo
$foo | Out-File -Path "D:\foo.log"
Another Cons of Write-Host is that, Write-Host can specified in what color the messages are shown in the console by using -ForegroundColor and -BackgroundColor.
On the other side, by using Write-Information, the input message can be used wherever we want via the No.6 pipeline. And doesn't need to write the extra codes like I write above. But the dark side of this is that, if we want to write messages to the console and also saved to the file, we have to do this:
# Always set the $InformationPreference variable to "Continue"
$InformationPreference = "Continue";
# if we don't want something like this:
# ======= Example 1 =======
# File Foo.ps1
$InformationPreference = "Continue";
Write-Information "Some Message"
Write-Information "Another Message"
# File AlwaysRunThisBeforeEverything.ps1
.\Foo.ps1 6>"D:\foo.log"
# ======= End of Example 1 =======
# then we have to add '6>"D:\foo.log"' to every lines of Write-Information like this:
# ======= Example 2 =======
$InformationPreference = "Continue";
Write-Information "Some Message" 6>"D:\foo.log"
Write-Information "Another Message" 6>"D:\foo.log"
# ======= End of Example 2 =======
A little bit redundant I think.
I only know a little aspect of this "vs" thing, and there must have something out of my mind. So is there anything else that can make me believe that Write-Information is better than Write-Host, please leave your kind answers here.
Thank you.
The Write-* cmdlets allow you to channel the output of your PowerShell code in a structured way, so you can easily distinguish messages of different severity from each other.
Write-Host: display messages to an interactive user on the console. Unlike the other Write-* cmdlets this one is neither suitable nor intended for automation/redirection purposes. Not evil, just different.
Write-Output: write the "normal" output of the code to the default (success) output stream ("STDOUT").
Write-Error: write error information to a separate stream ("STDERR").
Write-Warning: write messages that you consider warnings (i.e. things that aren't failures, but something that the user should have an eye on) to a separate stream.
Write-Verbose: write information that you consider more verbose than "normal" output to a separate stream.
Write-Debug: write information that you consider relevant for debugging your code to a separate stream.
Write-Information is just a continuation of this approach. It allows you to implement log levels in your output (Debug, Verbose, Information, Warning, Error) and still have the success output stream available for regular output.
As for why Write-Host became a wrapper around Write-Information: I don't know the actual reason for this decision, but I'd suspect it's because most people don't understand how Write-Host actually works, i.e. what it can be used for and what it should not be used for.
To my knowledge there isn't a generally accepted or recommended approach to logging in PowerShell. You could for instance implement a single logging function like #JeremyMontgomery suggested in his answer:
function Write-Log {
Param(
[Parameter(Mandatory=$true, Position=0)]
[ValidateNotNullOrEmpty()]
[string]$Message,
[Parameter(Mandatory=$false, Position=1)]
[ValidateSet('Error', 'Warning', 'Information', 'Verbose', 'Debug')]
[string]$LogLevel = 'Information'
)
switch ($LogLevel) {
'Error' { ... }
'Warning' { ... }
'Information' { ... }
'Verbose' { ... }
'Debug' { ... }
default { throw "Invalid log level: $_" }
}
}
Write-Log 'foo' # default log level: Information
Write-Log 'foo' 'Information' # explicit log level: Information
Write-Log 'bar' 'Debug'
or a set of logging functions (one for each log level):
function Write-LogInformation {
Param(
[Parameter(Mandatory=$true, Position=0)]
[ValidateNotNullOrEmpty()]
[string]$Message
)
...
}
function Write-LogDebug {
Param(
[Parameter(Mandatory=$true, Position=0)]
[ValidateNotNullOrEmpty()]
[string]$Message
)
...
}
...
Write-LogInformation 'foo'
Write-LogDebug 'bar'
Another option is to create a custom logger object:
$logger = New-Object -Type PSObject -Property #{
Filename = ''
Console = $true
}
$logger | Add-Member -Type ScriptMethod -Name Log -Value {
Param(
[Parameter(Mandatory=$true, Position=0)]
[ValidateNotNullOrEmpty()]
[string]$Message,
[Parameter(Mandatory=$false, Position=1)]
[ValidateSet('Error', 'Warning', 'Information', 'Verbose', 'Debug')]
[string]$LogLevel = 'Information'
)
switch ($LogLevel) {
'Error' { ... }
'Warning' { ... }
'Information' { ... }
'Verbose' { ... }
'Debug' { ... }
default { throw "Invalid log level: $_" }
}
}
$logger | Add-Member -Type ScriptMethod -Name LogDebug -Value {
Param([Parameter(Mandatory=$true)][string]$Message)
$this.Log($Message, 'Debug')
}
$logger | Add-Member -Type ScriptMethod -Name LogInfo -Value {
Param([Parameter(Mandatory=$true)][string]$Message)
$this.Log($Message, 'Information')
}
...
Write-Log 'foo' # default log level: Information
$logger.Log('foo') # default log level: Information
$logger.Log('foo', 'Information') # explicit log level: Information
$logger.LogInfo('foo') # (convenience) wrapper method
$logger.LogDebug('bar')
Either way you can externalize the logging code by
putting it into a separate script file and dot-sourcing that file:
. 'C:\path\to\logger.ps1'
putting it into a module and importing that module:
Import-Module Logger
To complement Ansgar's helpful and comprehensive answer:
Write-Host became (in essence) a wrapper for
Write-Information -InformationAction Continue in PSv5, presumably because:
it enables suppressing or redirecting Write-Host messages, which was not previously possible (in PowerShell 4 or below, Write-Host bypassed PowerShell's streams and output directly to the host),
while preserving backward compatibility in that the messages are output by default - unlike with Write-Information, whose default behavior is to be silent (because it respects preference variable $InformationPreference, whose default value is SilentlyContinue).
While Write-Host is therefore now (PSv5+) a bit of a misnomer — it doesn't necessarily write to the host anymore — it still has one distinct advantage over Write-Information (as you state): it can produce colored output with -ForegroundColor and -BackgroundColor.
Ansgar's answer has the conventional logging perspective covered, but PowerShell's Start-Transcript cmdlet may serve as a built-in alternative (see below).
As for your desire to output messages to the host while also capturing them in a log file:
PowerShell's session transcripts - via Start-Transcript and Stop-Transcript - may give you what you want.
As the name suggests, transcripts capture whatever prints to the screen (without coloring), which therefore by default includes success output, however.
Applied to your example:
$null = Start-Transcript "D:\foo.log"
$InformationPreference = "Continue"
Write-Information "Some Message"
Write-Information "Another Message"
$null = Stop-Transcript
The above will print messages to both the screen and the transcript file; note that, curiously, only in the file will they be prefixed with INFO:.
(By contrast, Write-Warning, Write-Verbose and Write-Debug - if configured to produce output - use prefix WARNING:, VERBOSE:, DEBUG: both on-screen and in the file; similarly, Write-Error produces "noisy" multiline input both on-screen and in the file.)
Note one bug that only affects Windows PowerShell (it has been fixed in PowerShell [Core].Thanks, JohnLBevan.): output from Write-Information shows up in the transcript file (but not on the screen) even when $InformationPreference is set to SilentlyContinue (the default); the only way to exclude Write-Information output (via the preference variable or -InformationAction parameter) appears to be a value of Ignore - which silences the output categorically - or, curiously, Continue, in which it only prints to the console, as PetSerAl points out.
In a nutshell, you can use Start-Transcript as a convenient, built-in approximation of a logging facility, whose verbosity you can control from the outside via the preference variables ($InformationPreference, $VerbosePreference, ...), with the following important differences from conventional logging:
Generally, what goes into the transcript file is also output to the console (which could generally be considered a plus).
However, success output (data output) is by default also sent to the transcript - unless you capture it or suppress it altogether - and you cannot selectively keep it out of the transcript:
If you capture or suppress it, it won't show in in the host (the console, by default) either[1].
The inverse, however, is possible: you can send output to the transcript only (without echoing it in the console), by way of Out-Default -Transcript Thanks, PetSerAl; e.g.,
'to transcript only' | Out-Default -Transcript; however, as of PowerShell 7.0 this appears to log the output twice in the transcript; also note that Out-Default is generally not meant to be called from user code - see this answer.
Generally, external redirections (applying > to a call to a script that internally performs transcription) keep streams out of the transcript, with two exceptions, as of PowerShell 7.0:
Write-Host output, even if 6> or *> redirections are used.
Error output, even if 2> or *> redirections are used.
However, using $ErrorActionPreference = 'SilentlyContinue' / 'Ignore' does keep non-terminating errors out of the transcript, but not terminating ones.
Transcript files aren't line-oriented (there's a block of header lines with invocation information, and there's no guarantee that output produced by the script is confined to a line), so you cannot expect to parse them in a line-by-line manner.
[1] PetSerAl mentions the following limited and somewhat cumbersome workaround (PSv5+) for sending success output to the console only, which notably precludes sending the output through the pipeline or capturing it:
'to console only' | Out-String -Stream | ForEach-Object { $Host.UI.WriteLine($_) }
PowerShell is about automation.
Sometimes, you run a script multiple times a day and you don't want to see the output all the time.
Write-Host has no possibility of hiding the output. It gets written on the Console, no matter what.
With Write-Information, you can specify the -InformationAction Parameter on the Script. With this parameter, you can specify if you want to see the messages (-InformationAction Continue) or not (-InformationAction SilentlyContinue)
Edit:
And please use "Some Message" | out-file D:\foo.log for logging, and neither Write-Host or Write-Information
Here's a generic version of a more specialized logging function that I used for a script of mine recently.
The scenario for this is that when I need to do something as a scheduled task, I typically create a generic script, or function in a module that does the "heavy lifting" then a calling script that handles the specifics for the particular job, like getting arguments from an XML config, logging, notifications, etc.
The inner script uses Write-Error, Write-Warning, and Write-Verbose, the calling script redirects all output streams down the pipeline to this function, which captures records the messages in a csv file with a Timestamp, Level, and Message.
In this case, it was targeted at PoSh v.4, so I basically am using Write-Verbose as a stand-in for Write-Information, but same idea. If I were to have used Write-Host in the Some-Script.ps1 (see example) instead of Write-Verbose, or Write-Information, the Add-LogEntry function wouldn't capture and log the message. If you want to use this to capture more streams appropriately, add entries to the switch statement to meet your needs.
The -PassThru switch in this case was basically a way to address exactly what you mentioned about both writing to a log file in addition to outputting to the console (or to another variable, or down the pipeline). In this implementation, I've added a "Level" property to the object, but hopefully you can see the point. My use case for this was to pass the log entries to a variable so that they could be checked for errors, and used in an SMTP notification if an error did occur.
function Add-LogEntry {
[CmdletBinding()]
param (
# Path to logfile
[Parameter(ParameterSetName = 'InformationObject', Mandatory = $true, Position = 0)]
[Parameter(ParameterSetName = 'Normal', Mandatory = $true, Position = 0)]
[String]$Path,
# Can set a message manually if not capturing an alternate output stream via the InformationObject parameter set.
[Parameter(ParameterSetName = 'Normal', Mandatory = $true)]
[String]$Message,
# Captures objects redirected to the output channel from Verbose, Warning, and Error channels
[ValidateScript({ #("VerboseRecord", "WarningRecord", "ErrorRecord") -Contains $_.GetType().name })]
[Parameter(ParameterSetName = 'InformationObject', Mandatory = $true, ValueFromPipeline = $true)]
$InformationObject,
# If using the message parameter, must specify a level, InformationObject derives level from the object.
[ValidateSet("Information", "Warning", "Error")]
[Parameter(ParameterSetName = 'Normal', Mandatory = $true, Position = 2)]
[String]$Level,
# Forward the InformationObject down the pipeline with additional level property.
[Parameter(ParameterSetName = 'InformationObject', Mandatory = $false)]
[Switch]$PassThru
)
Process {
# If using an information object, set log entry level according to object type.
if ($PSCmdlet.ParameterSetName -eq "InformationObject") {
$Message = $InformationObject.ToString()
# Depending on the object type, set the error level,
# add entry to cover "Write-Information" output here if needed
switch -exact ($InformationObject.GetType().name) {
"VerboseRecord" { $Level = "Information" }
"WarningRecord" { $Level = "Warning" }
"ErrorRecord" { $Level = "Error" }
}
}
# Generate timestamp for log entry
$Timestamp = (get-date).Tostring("yyyy\-MM\-dd\_HH\:mm\:ss.ff")
$LogEntryProps = #{
"Timestamp" = $Timestamp;
"Level" = $Level;
"Message" = $Message
}
$LogEntry = New-Object -TypeName System.Management.Automation.PSObject -Property $LogEntryProps
$LogEntry | Select-Object Timestamp, Level, Message | Export-Csv -Path $Path -NoTypeInformation -Append
if ($PassThru) { Write-Output ($InformationObject | Add-Member #{Level = $Level } -PassThru) }
}
}
Example usage would be
& $PSScriptRoot\Some-Script.ps1 -Param $Param -Verbose *>&1 | Add-LogEntry -Path $LogPath -PassThru
The -PassThru switch should essentially write the information object to the console if you don't capture the output in a variable or pass it down the pipe to something else.
Interesting: while the preference variables have been mentioned in the earlier answers, nobody has mentioned the common parameters -InformationVariable, -ErrorVariable and -WarningVariable.
They are designed to take the output from the corresponding Write-* commands in the script or command so you can do with it what you want.
They're not really suitable to use as a log of an entire session, because they need to be added to every command you run, and the command/script needs to support it. (can be as easy as adding [CmdletBinding()] at the top of you scipt if you don't have it already. See the documentation)
But it could be a good way to separate the warnings/error from the real output of a command. Just run it again with the proper parameters added.
For example -ErrorVariable ErrorList -ErrorAction SilentlyContinue.
Now all the errors are stored in the $ErrorList variable and you can write them in a file.
$ErrorList|Out-File -FilePath errors.txt
I have to admit that I hate PowerShell logging and all the Write-* commands... So I start all my scripts with the same function:
function logto{ ## Outputs data to Folder tree
Param($D,$P,$F,$C,$filename)
$LogDebug = $false
$FDomain =[System.DirectoryServices.ActiveDirectory.Forest]::GetCurrentForest()
$SCRdir = $MyInvocation.ScriptName
$FDNSName = $FDomain.Name
$RealFile = $F
if($ScriptName -eq $null){
$ScriptName = "\LogTo\"
}
## if there is a time stamp defined make it part of the directory
if($GlobalRunTime){
$Flocaldrive = $env:SystemDrive + "\" + $FDNSName + $ScriptName + $GlobalRunTime + "\"
If ($LogDebug) {Write-host "Set path to $Flocaldrive" -foregroundcolor Magenta}
}else{
$Flocaldrive = $env:SystemDrive + "\" + $FDNSName + $ScriptName
If ($LogDebug) {Write-host "Set path to $Flocaldrive" -foregroundcolor Magenta}
}
## do not write null data
if ($D -eq $null) {
If ($LogDebug) {Write-host "$RealFile :Received Null Data Exiting Function" -foregroundcolor Magenta}
Return
}
## if no path is chosen default to
if ($P -eq $null) {
$PT = $Flocaldrive
If ($LogDebug) {Write-host "Path was Null, setting to $PT" -foregroundcolor Magenta}
}else{
$PT = $Flocaldrive + $P
If ($LogDebug) {Write-host "Path detected as $p, setting path to $PT" -foregroundcolor Magenta}
}
## anything with no file goes to Catchall
If ($RealFile-eq $null) {
If ($LogDebug) {Write-host "$D :attempting to write to Null file name, redirected out to Catchall" -foregroundcolor Magenta}
$RealFile= "\Catchall.txt"
}
##If color is blank DONT write to screen
if ($C -eq $null) {
If ($LogDebug) {Write-host "Color was blank so not writing to screen" -foregroundcolor Magenta}
}else{
If ($LogDebug) {Write-host "Attempting to write to console in $C" -foregroundcolor Magenta}
write-host $D -foregroundcolor $C
}
###### Write standard format
$DataFile = $PT + $RealFile## define path with File
## Check if path Exists if not create it
If (Test-Path $PT) {
If ($LogDebug) {Write-host "$PT :Directory Exists" -foregroundcolor Magenta}
}else{
New-Item $PT -type directory | out-null ## if directory does not exist create it
If ($LogDebug) {Write-host "Creating directory $PT" -foregroundcolor Magenta}
}
## If file exist if not create it
If (Test-Path $DataFile) { ## If file does not exist create it
If ($LogDebug) {Write-host "$DataFile :File Exists" -foregroundcolor Magenta}
}else{
New-Item $DataFile -type file | out-null ## if file does not exist create it, we cant append a null file
If ($LogDebug) {Write-host "$DataFile :File Created" -foregroundcolor Magenta}
}
## Write our data to file
$D | out-file -Filepath $DataFile -append ## Write our data to file
## Write to color coded files
if ($C -ne $null) {
$WriteSumDir = $Flocaldrive + "Log\Sorted"
$WriteSumFile = $WriteSumDir + "\Console.txt"
## Check if path Exists if not create it
If (Test-Path $WriteSumDir) {
If ($LogDebug) {Write-host "$WriteSumDir :Directory Exists" -foregroundcolor Magenta}
}else{
New-Item $WriteSumDir -type directory | out-null ## if directory does not exist create it
If ($LogDebug) {Write-host "Creating directory $WriteSumDir" -foregroundcolor Magenta}
}
## If file does not exist create it
If (Test-Path $WriteSumFile) {
If ($LogDebug) {Write-host "$WriteSumFile :File Exists" -foregroundcolor Magenta}
}else{
New-Item $WriteSumFile -type file | out-null ## if file does not exist create it, we cant append a null file
If ($LogDebug) {Write-host "$WriteSumFile :File Created" -foregroundcolor Magenta}
}
## Write our data to file
$D | out-file -Filepath $WriteSumFile -append ## write everything to same file
## Write our data to color coded file
$WriteColorFile = $WriteSumDir + "\$C.txt"
If (Test-Path $WriteColorFile) { ## If file does not exist create it
If ($LogDebug) {Write-host "$WriteColorFile :File Exists" -foregroundcolor Magenta}
}else{
New-Item $WriteColorFile -type file | out-null ## if file does not exist create it, we cant append a null file
If ($LogDebug) {Write-host "$WriteColorFile :File Created" -foregroundcolor Magenta}
}
## Write our data to Color coded file
$D | out-file -Filepath $WriteColorFile -append ## write everything to same file
}
## If A return was not specified
If($filename -ne $null){
Return $DataFile
}
}
I have two Powershell files, a module and a script that calls the module.
Module: test.psm1
Function Get-Info {
$MyInvocation.MyCommand.Name
}
Script: myTest.ps1
Import-Module C:\Users\moomin\Documents\test.psm1 -force
Get-Info
When I run ./myTest.ps1 I get
Get-Info
I want to return the name of the calling script (test.ps1). How can I do that?
Use PSCommandPath instead in your module:
Example test.psm1
function Get-Info{
$MyInvocation.PSCommandPath
}
Example myTest.ps1
Import-Module C:\Users\moomin\Documents\test.psm1 -force
Get-Info
Output:
C:\Users\moomin\Documents\myTest.ps1
If you want only the name of the script that could be managed by doing
GCI $MyInvocation.PSCommandPath | Select -Expand Name
That would output:
myTest.ps1
I believe you could use the Get-PSCallStack cmdlet, which returns an array of stack frame objects. You can use this to identify the calling script down to the line of code.
Module: test.psm1
Function Get-Info {
$callstack = Get-PSCallStack
$callstack[1].Location
}
Output:
myTest.ps1: Line 2
Using the $MyInvocation.MyCommand is relative to it's scope.
A simple example (Of a script located : C:\Dev\Test-Script.ps1):
$name = $MyInvocation.MyCommand.Name;
$path = $MyInvocation.MyCommand.Path;
function Get-Invocation(){
$path = $MyInvocation.MyCommand.Path;
$cmd = $MyInvocation.MyCommand.Name;
write-host "Command : $cmd - Path : $path";
}
write-host "Command : $cmd - Path : $path";
Get-Invocation;
The output when running .\c:\Dev\Test-Script.ps1 :
Command : C:\Dev\Test-Script.ps1 - Path : C:\Dev\Test-Script.ps1
Command : Get-Invocation - Path :
As you see, the $MyInvocation is relative to the scoping. If you want the path of your script, do not enclose it in a function. If you want the invocation of the command, then you wrap it.
You could also use the callstack as suggested, but be aware of scoping rules.
I used this today after trying a couple of techniques.
$scriptPath = split-path -parent $MyInvocation.MyCommand.Definition
$ScriptName = $MyInvocation.MyCommand | select -ExpandProperty Name
Invoke-Expression ". $Script\$ScriptName"
To refer to the invocation info of the calling script, use:
#(Get-PSCallStack)[1].InvocationInfo
e.g.:
#(Get-PSCallStack)[1].InvocationInfo.MyCommand.Name
This provides the script path with trailing backslash as one variable and the script name as another.
The path works with Powershell 2.0 and 3.0 and 4.0 and probably 5.0
Where with Posershell $PSscriptroot is now available.
$_INST = $myinvocation.mycommand.path.substring(0,($myinvocation.mycommand.path.length - $MyInvocation.mycommand.name.length))
$_ScriptName = $myinvocation.mycommand.path.substring($MyInvocation.MyCommand.Definition.LastIndexOf('\'),($MyInvocation.mycommand.name.length +1))
$_ScriptName = $_ScriptName.TrimStart('\')
If you want a more reusable approach, you can use:
function Get-CallingFileName
{
$cStack = #(Get-PSCallStack)
$cStack[$cStack.Length-1].InvocationInfo.MyCommand.Name
}
The challenge I had was having a function that could be reused within the module. Everything else assumed that the script was calling the module function directly and if it was removed even 1 step, then the result would be the module file name. If, however, the source script is calling a function in the module which is, in turn, calling another function in the module, then this is the only answer I've seen that can ensure you're getting the source script info.
Of course, this approach is based on what #iRon and #James posted.
For you googlers looking for quick copy paste solution,
here is what works in Powershell 5.1
Inside your module:
$Script = (Get-PSCallStack)[2].Command
This will output just the script name (ScriptName.ps1) which invoked a function located in module.
I use this in my module:
function Get-ScriptPath {
[CmdletBinding()]
param (
[string]
$Extension = '.ps1'
)
# Allow module to inherit '-Verbose' flag.
if (($PSCmdlet) -and (-not $PSBoundParameters.ContainsKey('Verbose'))) {
$VerbosePreference = $PSCmdlet.GetVariableValue('VerbosePreference')
}
# Allow module to inherit '-Debug' flag.
if (($PSCmdlet) -and (-not $PSBoundParameters.ContainsKey('Debug'))) {
$DebugPreference = $PSCmdlet.GetVariableValue('DebugPreference')
}
$callstack = Get-PSCallStack
$i = 0
$max = 100
while ($true) {
if (!$callstack[$i]) {
Write-Verbose "Cannot detect callstack frame '$i' in 'Get-ScriptPath'."
return $null
}
$path = $callstack[$i].ScriptName
if ($path) {
Write-Verbose "Callstack frame '$i': '$path'."
$ext = [IO.Path]::GetExtension($path)
if (($ext) -and $ext -eq $Extension) {
return $path
}
}
$i++
if ($i -gt $max) {
Write-Verbose "Exceeded the maximum of '$max' callstack frames in 'Get-ScriptPath'."
return $null
}
}
return $null
}
You can grab the automatic variable MyInvocation from the parent scope and get the name from there.
Get-Variable -Scope:1 -Name:MyInvocation -ValueOnly
I did a basic test to check to see if it would always just get the direct parent scope and it worked like a treat and is extremely fast as opposed to Get-PSCallStack
function ScopeTest () {
Write-Information -Message:'ScopeTest'
}
Write-nLog -Message:'nLog' -Type:110 -SetLevel:Verbose
ScopeTest
By default, any named function that has the [CmdletBinding()] attribute accepts the -debug and -verbose (and a few others) parameters and has the predefined $debug and $verbose variables. I'm trying to figure out how to pass them on to other cmdlet's that get called within the function.
Let's say I have a cmdlet like this:
function DoStuff() {
[CmdletBinding()]
PROCESS {
new-item Test -type Directory
}
}
If -debug or -verbose was passed into my function, I want to pass that flag into the new-item cmdlet. What's the right pattern for doing this?
$PSBoundParameters isn't what you're looking for. The use of the [CmdletBinding()] attribute allows the usage of $PSCmdlet within your script, in addition to providing a Verbose flag. It is in fact this same Verbose that you're supposed to use.
Through [CmdletBinding()], you can access the bound parameters through $PSCmdlet.MyInvocation.BoundParameters. Here's a function that uses CmdletBinding and simply enters a nested prompt immediately in order examine the variables available inside the function scope.
PS D:\> function hi { [CmdletBinding()]param([string] $Salutation) $host.EnterNestedPrompt() }; hi -Salutation Yo -Verbose
PS D:\>>> $PSBoundParameters
____________________________________________________________________________________________________
PS D:\>>> $PSCmdlet.MyInvocation.BoundParameters
Key Value
--- -----
Salutation Yo
Verbose True
So in your example, you would want the following:
function DoStuff `
{
[CmdletBinding()]
param ()
process
{
new-item Test -type Directory `
-Verbose:($PSCmdlet.MyInvocation.BoundParameters["Verbose"].IsPresent -eq $true)
}
}
This covers -Verbose, -Verbose:$false, -Verbose:$true, and the case where the switch is not present at all.
Perhaps it sounds strange, but there isn't any easy way for a cmdlet to know its verbose or debug mode. Take a look at the related question:
How does a cmdlet know when it really should call WriteVerbose()?
One not perfect, but practically reasonable, option is to introduce your own cmdlet parameters (for example, $MyVerbose and $MyDebug) and use them in the code explicitly:
function DoStuff {
[CmdletBinding()]
param
(
# Unfortunately, we cannot use Verbose name with CmdletBinding
[switch]$MyVerbose
)
process {
if ($MyVerbose) {
# Do verbose stuff
}
# Pass $MyVerbose in the cmdlet explicitly
New-Item Test -Type Directory -Verbose:$MyVerbose
}
}
DoStuff -MyVerbose
UPDATE
When we need only a switch (not, say, a verbosity level value) then the approach with $PSBoundParameters is perhaps better than proposed in the first part of this answer (with extra parameters):
function DoStuff {
[CmdletBinding()]
param()
process {
if ($PSBoundParameters['Verbose']) {
# Do verbose stuff
}
New-Item Test -Type Directory -Verbose:($PSBoundParameters['Verbose'] -eq $true)
}
}
DoStuff -Verbose
It's all not perfect anyway. If there are better solutions then I would really like to know them myself.
There is no need. PowerShell already does this as the code below proves.
function f { [cmdletbinding()]Param()
"f is called"
Write-Debug Debug
Write-Verbose Verbose
}
function g { [cmdletbinding()]Param()
"g is called"
f
}
g -Debug -Verbose
The output is
g is called
f is called
DEBUG: Debug
VERBOSE: Verbose
It is not done as direct as passing -Debug to the next cmdlet though. It is done through the $DebugPreference and $VerbrosePreference variables. Write-Debug and Write-Verbose act like you would expect, but if you want to do something different with debug or verbose you can read here how to check for yourself.
Here's my solution:
function DoStuff {
[CmdletBinding()]
param ()
BEGIN
{
$CMDOUT = #{
Verbose = If ($PSBoundParameters.Verbose -eq $true) { $true } else { $false };
Debug = If ($PSBoundParameters.Debug -eq $true) { $true } else { $false }
}
} # BEGIN ENDS
PROCESS
{
New-Item Example -ItemType Directory #CMDOUT
} # PROCESS ENDS
END
{
} #END ENDS
}
What this does different from the other examples is that it will repsect "-Verbose:$false" or "-Debug:$false". It will only set -Verbose/-Debug to $true if you use the following:
DoStuff -Verbose
DoStuff -Verbose:$true
DoStuff -Debug
DoStuff -Debug:$true
You could build a new hash table based on the bound debug or verbose parameters and then splat it to the internal command. If you're just specifying switches (and aren't passing a false switch, like $debug:$false) you can just check for the existence of debug or verbose:
function DoStuff() {
[CmdletBinding()]
PROCESS {
$HT=#{Verbose=$PSBoundParameters.ContainsKey'Verbose');Debug=$PSBoundParameters.ContainsKey('Debug')}
new-item Test -type Directory #HT
}
}
If you want to pass the parameter value it's more complicated, but can be done with:
function DoStuff {
[CmdletBinding()]
param()
PROCESS {
$v,$d = $null
if(!$PSBoundParameters.TryGetValue('Verbose',[ref]$v)){$v=$false}
if(!$PSBoundParameters.TryGetValue('Debug',[ref]$d)){$d=$false}
$HT=#{Verbose=$v;Debug=$d}
new-item Test -type Directory #HT
}
}
The best way to do it is by setting the $VerbosePreference. This will enable the verbose level for the entire script. Do not forget to disable it by the end of the script.
Function test
{
[CmdletBinding()]
param($param1)
if ($psBoundParameters['verbose'])
{
$VerbosePreference = "Continue"
Write-Verbose " Verbose mode is on"
}
else
{
$VerbosePreference = "SilentlyContinue"
Write-Verbose " Verbose mode is Off"
}
# <Your code>
}
You can set the VerbosePreference as a global variable on starting your script and then check for the global variable in your custom cmdlet.
Script:
$global:VerbosePreference = $VerbosePreference
Your-CmdLet
Your-CmdLet:
if ($global:VerbosePreference -eq 'Continue') {
# verbose code
}
Checking explicitly for 'Continue' allows the script to be equal to -verbose:$false when you call the CmdLet from a script that doesn't set the global variable (in which case it's $null)
You do not have to do any checks or comparisons. Even though -Verbose (and -Debug) are of type [switch], they seem to understand not just $true and $false but also their preference variable. The preference variable also gets inherited correctly to all child functions that are called. I tried this on Powershell version 7.3.2 and it works as expected.
function Parent {
[CmdletBinding()]param()
Child
}
function Child {
[CmdletBinding()]param()
New-Item C:\TEST\SomeDir -Force -ItemType Directory -Verbose:$VerbosePreference -Debug:$DebugPreference
}
Parent -Verbose
Parent -Debug
I think this is the easiest way:
Function Test {
[CmdletBinding()]
Param (
[parameter(Mandatory=$False)]
[String]$Message
)
Write-Host "This is INFO message"
if ($PSBoundParameters.debug) {
Write-Host -fore cyan "This is DEBUG message"
}
if ($PSBoundParameters.verbose) {
Write-Host -fore green "This is VERBOSE message"
}
""
}
Test -Verbose -Debug