I have a large Powershell script that checks multiple variables on VMs. The script consists of about 80 different functions that are named question1, question2, question3...
At first none of the functions needed parameters, so this code worked.
$number_of_questions = 1..75
foreach($num in $number_of_questions){
Invoke-Expression question$num
}
It iterates thru every question
But now i need to add parameters for when i run the functions. And that doesn't work. And i cant find a way to get it to work with arguments
Here´s a testversion of what im trying to do.
function test1($text){
Write-host "Not argument"
Write-host $text
}
function test2($text){
Write-host "Not argument"
Write-host $text
}
function test3($text){
Write-host "Not argument"
Write-host $text
}
function test4($text){
Write-host "Not argument"
Write-host $text
}
function test5($text){
Write-host "Not argument"
Write-host $text
}
$num = 1..5
foreach($number in $num){
Invoke-Expression test$number -text "Argument"
}
Does anyone have a solution for running multiple functions with sequenced names that uses parameters.
Just replace:
Invoke-Expression test$number -text "Argument"
with:
Invoke-Expression "test$number -text `"Argument`""
to make it work.
Related
function User-Search($input)
{
Write-Host "Searching for user: $input"
pause
}
function Show-Menu
{
param (
[string]$Title = 'MainMenu'
)
cls
Write-Host "================ $Title ================"
Write-Host " "
Write-Host "Specify computer / username"
Write-Host " "
Write-Host "Q: Press 'Q' to quit."
Write-Host " "
}
do
{
Show-Menu
$input = Read-Host "Search"
User-Search -input $input
}
until ($input -eq 'q')
Outputs: "Searching for user:", it's empty.
There must be some small mistake i am doing, probably easy for you guys :)
$INPUT is an automatic variable:
Contains an enumerator that enumerates all input that is passed to a
function. The $input variable is available only to functions and
script blocks (which are unnamed functions).
So just use another variable, e. g. $user instead of $input
My main PowerShell code runs a function that logs to the Windows eventlog. If the level is error it uses a separate event ID which then our monitoring will pick up that exact ID and run an action. However, if I want to specify in the parameter of the main script (not the function) that this time running it use a different Event ID so it will NOT action monitoring, I don't know where to even start on that.
Is there a way to provide a switch parameter in the main script like $NoAlert which then changes the Event ID in the function?
The function of logging lives in a PowerShell module I created. I am importing the module at the beginning of the script and then calling the function during the main script body.
Here is the function:
function WriteLog-SRTProd {
Param(
[string]$logT,
[Parameter(Mandatory=$true)][string]$level,
[String]$LogFileDirT = "\\ServerA\Logs"
)
$RSLogfileT = (Get-ChildItem -Path $LogFileDirT |
sort LastWriteTime |
select -Last 1).Name
## make sure a level is correctly selected (mandatory)
if ("Error","Info","Warn" -NotContains $Level) {
throw "$($Environment) is not a valid name! Please use 'Error', 'Warn', or 'Info'"
}
if ($Level -eq "Info") {
Add-Content -Path "$LogFileDirT\$RSLogFileT" -Value "$(Get-Date -format MM-dd-yyyy::HH:mm:ss) INFO $logT"
Write-EventLog -LogName Application -Source TEST_MAINT -EntryType Information -EventId 100 -Message $logT -Category 0
}
if ($Level -eq "Warn") {
Add-Content -Path "$LogFileDirT\$RSLogFileT" -Value "$(Get-Date -format MM-dd-yyyy::HH:mm:ss) WARN $logT"
Write-EventLog -LogName Application -Source TEST_MAINT -EntryType Warning -EventId 200 -Message $logT -Category 0
}
if ($Level -eq "Error") {
Add-Content -Path "$LogFileDirT\$RSLogFileT" -Value "$(Get-Date -format MM-dd-yyyy::HH:mm:ss) ERROR $logT"
Write-EventLog -LogName Application -Source TEST_MAINT -EntryType Error -EventId 300 -Message $logT -Category 0
}
}
I'd like to run my script like this. When the $NoAlert is passed, it will send that switch to the function. Is this possible? Can I just add the switch in both places and use an if statement in the function for when the NoAlert switch is used?
PS C:\> .\Maintenance.ps1 -NoAlert
Param(
[switch]$NoAlert
)
WriteLog-SRTProd -level Error -logT "Custom Error Message"
I have created own function for logging and stored/installed as module, below is the part of my log module :
you can customize the write statements and add your code for event log. I have added 'NoAction' enum member as per your requirements.
I have used one Enum to separate the log levels
Enum Severity
{
Error = 3
Warning = 4
Informational = 6
Debug = 7
Verbose = 8
NoAction = 0 # AS PER YOUR REQUIREMENTS
}
function Write-Log()
{
[cmdletbinding()]
param
(
[Parameter(Position=0,mandatory=$true)]
[Severity] $LogLevel,
[Parameter(Position=1,mandatory=$true)]
[String] $Message
)
$TimeStamp = "$(Get-Date -format HH:mm:ss)" ;
Switch($LogLevel)
{
([Severity]::Error.ToString())
{
Write-Error "`t$TimeStamp : $Message`n" -ErrorAction Stop
break;
}
([Severity]::Warning.ToString())
{
Write-Warning "`t$TimeStamp : $Message`n" -WarningAction Continue
break;
}
([Severity]::Informational.ToString())
{
Write-Information "INROMATION:`t$TimeStamp : $Message`n" -InformationAction Continue
break;
}
([Severity]::Verbose.ToString())
{
Write-Verbose "`t$TimeStamp : $Message`n"
break;
}
([Severity]::NoAction.ToString())
{
Write-Verbose "`t$TimeStamp : $Message`n"
break;
}
} # END OF SWITCH
} # END OF FUNCTION
Sample Call :
Write-Log -LogLevel ([Severity]::Informational) -Message "test log message using info level"
Output :
INROMATION: 09:40:15 : test log message using info level
I have decided to just add a new parameter to both function and main script named $NoAlert. I have added an If($NoAlert){WriteLog-SRPProd -NoAlert} to the main script (messy, but its what I needed done). then in the Function, If($NoAlert){EventID 111}. so basically I am using the switch in the main script that then calls the NoAlert switch in the function. This is all done with a few added If/Else statements.
Hopefully that makes sense. Like I said its not the best answer, but I wanted to get it done and still provide an answer here in this post.
It seems that PowerShell adds an additional variable to the return value of a function.
The function subfoo2 itself delivers the correct values, but as soon as PowerShell jumps back to the postion where I called the function (in foo1), value contains the value of an other variable ($msg)
(Have a look at the comments in the code)
writeMessageLog($msg){
...
Add-Content $msg
...
}
subfoo2{
writeMessageLog($msg)
return $UserArrayWithValues #During Debug, $Array is fine (1)
}
foo1{
$var = subfoo2 $UserArray # $var has now the value of $msg and $UserArrayWithValues (2)
#do something with var
}
Realcode:
function WriteLog
{
param ( [string] $severity , $msgNumber, [string] $msg )
...
$msgOut = $date + ... + $msg
Add-Content $msgout ( $msgOut )
...
}
function getFeatures
{
writelog 'I' 1002 $true $true "Load Features"
$Features = importCsv -pPath $FeatureDefintionFilePath
Writelog 'I' 1000 $true $true "Features Loaded"
return $Features # $Features has value as expected (1)
}
function GetUserFeatures ($pUserObject)
{
$SfBFeatures = ""
$SfBFeatures = getFeatures #SfBFeaures has Value of $msg and $Features (2)
...
}
Do I use the functions/return values wrong? What could lead to such behavior? Is it an issue if i call a function within a function?
If I remove $msgOut = $date + ... + $msg in writeMessageLog, the values are fine.
I'm pretty lost right now, and have no ideas where this comes from. Any ideas welcome.
This is how powershell works, basically everything that you print out will be returned as the function output. So don't output extra stuff. To force something to not output stuff you can do:
$null = some-command_that_outputs_unwanted_things
since everybody is obsessed with Out-Null I'll add this link showing several other ways to do that.
Within a function, everything you don't assign or pipe to a consuming cmdlet will get put to the pipeline and returned from the function - even if you don't explicit return it. In fact the return keyword doesn't do anything in PowerShell so the following is equivalent:
function Test-Func
{
"Hello World"
}
function Test-Func
{
return "Hello World"
}
So it looks like your writeMessageLog puts anything on the pipeline thus you have to either assign the value to anything:
$notUsed = writeMessageLog($msg)
or (prefered) pipe it to the Out-Null cmdlet:
writeMessageLog($msg) | Out-Null
Early on in my script I have check to define whether a parameter "-Silent" was used when running the script. The idea is to have zero output from the script if it was and it will be checked on every Write-Host entry I have later. It seems a bit heavy to make if-else statements on every single Write-Host I have, so I decided to go with a function - something like this:
Function Silent-Write ([string]$arg1)
{
if ($silent -eq $false) {
if ($args -ieq "-nonewline") {
Write-Host "$arg1" -NoNewLine
}
elseif ($args -ieq "-foregroundcolor") {
Write-Host "$arg1" -ForegroundColor $args
}
else {
Write-Host "$arg1"
}
}
}
Silent-Write -ForegroundColor red "hello"
This is not working, but you get the idea; besides passing the text I want to output, Silent-Write function should also take other Write-Host arguments into consideration. Quite simple issue I believe, but something I cannot figure out with the knowledge of functions I have.
In PowerShell V3 you can use splatting:
Function Silent-Write
{
if (!$silent) {
Write-Host #args
}
}
Silent-Write -ForegroundColor red "hello"
Is there a way to create a parameter in a PowerShell function where you have to call it in order to have it considered?
An example given by commandlet (the bold being what I want to do):
Invoke-Command -computername Server01 -Scriptblock {...}
Here is an example of what I want to do with the function
Function DoStuff($computername, -arg2, -domain $domain)
Test-parameter(-domain) if (-domain -eq $true) {
use $domain
}
Else {
$domain = "Domain1"
}
test-parameter($arg2) {
if ($arg2 -eq $true) {
Do something
}
else {
Do the opposite
}
}
So in summary:
If "-arg2" is present, I want something to happen in the script. If "-Domain" is present and has an argument with it, I want that to be used rather then the set argument.
Powershell provides a lot of built-in support for common parameter scenarios, including mandatory parameters, optional parameters, "switch" (aka flag) parameters, and "parameter sets."
By default, all parameters are optional. The most basic approach is to simply check each one for $null, then implement whatever logic you want from there. This is basically what you have already shown in your sample code.
If you want to learn about all of the special support that Powershell can give you, check out these links:
about_Functions
about_Functions_Advanced
about_Functions_Advanced_Parameters
I don't think your question is very clear, this code assumes that if you're going to include the -domain parameter, it's always 'named' (i.e. dostuff computername arg2 -domain domain); this also makes the computername parameter mandatory.
Function DoStuff(){
param(
[Parameter(Mandatory=$true)][string]$computername,
[Parameter(Mandatory=$false)][string]$arg2,
[Parameter(Mandatory=$false)][string]$domain
)
if(!($domain)){
$domain = 'domain1'
}
write-host $domain
if($arg2){
write-host "arg2 present... executing script block"
}
else{
write-host "arg2 missing... exiting or whatever"
}
}
Not sure I understand the question correctly.
From what I gather, you want to be able to assign a value to Domain if it is null and also what to check if $args2 is supplied and according to the value, execute a certain code?
I changed the code to reassemble the assumptions made above.
Function DoStuff($computername, $arg2, $domain)
{
if($domain -ne $null)
{
$domain = "Domain1"
}
if($arg2 -eq $null)
{
}
else
{
}
}
DoStuff -computername "Test" -arg2 "" -domain "Domain2"
DoStuff -computername "Test" -arg2 "Test" -domain ""
DoStuff -computername "Test" -domain "Domain2"
DoStuff -computername "Test" -arg2 "Domain2"
Did that help?