How can I script "Does String -contains -not _" / "Does the string contain anything other than _"?
I'm not stuck as I've found a good enough work around. More curiosity than anything else.
Example:
$String = 1,1,1,2,5
$String -contains !(1)
This always comes up False
My solution at the moments is to remove the 1's and see if it's null like so:
$String2 = $String -ne 1
if ([String]::IsNullOrEmpty($String2)) {
Write-Host "True"
} else {
Write-Host "False"
}
Real World Example:
My script is designed to try a certain action until it works. In this case get-msoluser.
At the end of my script I want to count any errors (and list them later) but there will always be an error listed for "get-msoluser" as it fails until it works. So I'm trying to not include that certain error in the count.
$Errors = $Error.InvocationInfo.MyCommand.Name
if ($Errors -contains !("get-msoluser")) {
Write-Host "There was an error I actually care about"
}
INSTEAD I have to do this:
$Errors = $Error.InvocationInfo.MyCommand.Name
$ErrorsICareAbout = $Errors -ne "get-msoluser"
if ([String]::IsNullOrEmpty($ErrorsICareAbout)) {
Write-Host "$ErrorsICareAbout.Count"
} else {
Write-Host "There were errors you actually cared about"
}
Am I missing something that's right under my nose?
You simply need to use -notcontains or add the not operator around then entire -contains comparison like this:
If ($Errors -notcontains ("get-msoluser"))
or
If (!($Errors -contains ("get-msoluser")))
Rather than filtering out the error, try not producing an error in the first place. To suppress errors from a particular command, you can set the error action to SilentlyContinue.
Write-Error 'fail' -ErrorAction SilentlyContinue
So in the case of retrying until Get-MsOlUser works, you could use something like
while($msolUser -eq $null) {
$msolUser = Get-MsOlUser ... -ErrorAction SilentlyContinue
#Wait a second before retrying.
Start-Sleep -Seconds 1
}
#Now work with $msolUser
(You probably also want to put an upper limit on the number of retries)
Related
Hello and good morning(:
I'm looking to see if I'm able to jump to somewhere in PS without wrapping it in a ScriptBlock; hell, I'd even be okay with that but, I'm just unsure on how to go about it.
What I'm trying to do is: add a Parameter Set to a function and if something is supplied to the parameter -GrpSelec(I know imma change it), then just skip the rest of the script and go to my $swap variable to perform the switch.
$Group1 = #("1st Group", "2nd Group")
$Group2 = #("3rd Group", "4th Group")
Function Test-Group{
param(
[ValidateSet("Group1","group2")]
[array]$GrpSelec)
if($GrpSelec){ &$swap }
$AllGroups = #("Group1", "Group2")
for($i=0; $i -lt $AllGroups.Count; $i++){
Write-Host "$($i): $($AllGroups[$i])"}
$GrpSelec = Read-Host -Prompt "Select Group(s)"
$GrpSelec = $GrpSelec -split " "
$swap = Switch -Exact ($GrpSelec){
{1 -or "Group1"} {"$Group1"}
{2 -or "Group2"} {"$Group2"}
}
Foreach($Group in $swap){
"$Group"}
}
Is something like this even possible?
I've googled a couple of similar questions which point to the invocation operator &(as shown above), and/or, a foreach which is definitely not the same lol.
take it easy on me, im just experimenting(:
How about a simple if statement?
function Test-Group {
param(
[string[]]$GrpSelec
)
if(!$PSBoundParameters.ContainsKey('GrpSelect')){
# no argument was passed to -GrpSelec,
# populate $GrpSelec in here before proceeding with the rest of the script
}
# Now that $GrpSelec has been populated, let's do the work
$swap = Switch -Exact ($GrpSelec){
{1 -or "Group1"} {"$Group1"}
{2 -or "Group2"} {"$Group2"}
}
# rest of function
}
Very new to coding in general, so I fear I am missing something completely obvious. I want my program to check for a file. If it is there, just continue the code. If it has not arrived, continue cheking for a given amount of time, or untill the file shows up. My loop works on its own, so when i only select the do-part in Powershell ISE, it works. But when i try running it inside the if statement, nothing happens. The loops doesnt begin.
$exists= Test-Path $resultFile
$a = 1
if ($exists -eq "False")
{
do
{
$a++
log "Now `$a is $a "
start-sleep -s ($a)
$exists= Test-Path $resultFile
write-host "exists = $exists"
}
while (($a -le 5) -and ($exists -ne "True"))
}
Another way of doing this is using a while loop:
$VerbosePreference = 'Continue'
$file = 'S:\myFile.txt'
$maxRetries = 5; $retryCount = 0; $completed = $false
while (-not $completed) {
if (Test-Path -LiteralPath $file) {
Write-Verbose "File '$file' found"
$completed = $true
# Do actions with your file here
}
else {
if ($retryCount -ge $maxRetries) {
throw "Failed finding the file within '$maxRetries' retries"
} else {
Write-Verbose "File not found, retrying in 5 seconds."
Start-Sleep '5'
$retryCount++
}
}
}
Some tips:
Try to avoid Write-Host as it kills puppies and the pipeline (Don Jones). Better would be, if it's meant for viewing the script's progress, to use Write-Verbose.
Try to be consistent in spacing. The longer and more complex your scripts become, the more difficult it will be to read and understand them. Especially when others need to help you. For this reason, proper spacing helps all of us.
Try to use Tab completion in the PowerShell ISE. When you type start and press the TAB-key, it will automatically propose the options available. When you select what you want with the arrow down/up and press enter, it will nicely format the CmdLet to Start-Sleep.
The most important tip of all: keep exploring! The more you try and play with PowerShell, the better you'll get at it.
As pointed out in comments, your problem is that you're comparing a boolean value with the string "False":
$exists -eq "False"
In PowerShell, comparison operators evaluate arguments from left-to-right, and the type of the left-hand argument determines the type of comparison being made.
Since the left-hand argument ($exists) has the type [bool] (a boolean value, it can be $true or $false), PowerShell tries to convert the right-hand argument to a [bool] as well.
PowerShell interprets any non-empty string as $true, so the statement:
$exists -eq "False"
is equivalent to
$exists -eq $true
Which is probably not what you intended.
I'm trying to avoid using nested ForEach Loop as part of a larger code. To do this, I'm using the -notcontains operator. Basically, I want to see if a substring exists within a string within an array. If it exists, do nothing, if it does not exist, print "Not Found".
Here is the code...
$arr = #('"value11","value21","value31"','"value12","value22","value32"','"value13","value23","value33"')
if ($arr -notcontains "*`"value24`"*")
{
Write-Host "Not Found"
}
if ($arr -notcontains "*`"value22`"*")
{
Write-Host "Not Found 2"
}
We can see that value24 is not within any strings of the array. However, value22 is within the 2nd string in the array.
Therefor the results should output the following...
Not Found
However, instead I see the following output...
Not Found
Not Found 2
Can anyone tell me why this is happening?
-contains and -notcontains don't operate against patterns.
Luckily, -match and -like and their negative counterparts, when used with an array on the left side, return an array of the items that satisfy the condition:
'apple','ape','vape' -like '*ape'
Returns:
ape
vape
In an if statement, this still works (a 0 count result will be interpreted as $false):
$arr = #('"value11","value21","value31"','"value12","value22","value32"','"value13","value23","value33"')
if ($arr -notlike "*`"value24`"*")
{
Write-Host "Not Found"
}
My take on a solution:
($arr | foreach {$_.contains('"value24"')}) -contains $true
Using the V3 .foreach() method:
($arr.ForEach({$_.contains('"value24"')}).contains($true))
And yet another possibility:
[bool]($arr.where({$_.contains('"value24"')}))
Edit for clearer answer on what I'm looking for...
This is the only way I'm able to figure this out so far. I hope there is a much cleaner solution...
$arr = #('"value11","value21","value31"','"value12","value22","value32"','"value13","value23","value33"')
$itemNotFound = $true
ForEach ($item in $arr)
{
If ($itemNotFound)
{
If ($item -like "*`"value24`"*")
{
$itemNotFound = $false
}
}
}
if ($itemNotFound)
{
Write-Host "Not Found value24"
}
$itemNotFound = $true
ForEach ($item in $arr)
{
If ($itemNotFound)
{
If ($item -like "*`"value22`"*")
{
$itemNotFound = $false
}
}
}
if ($itemNotFound)
{
Write-Host "Not Found value22"
}
output will be:
Not Found value24
Very new to coding in general, so I fear I am missing something completely obvious. I want my program to check for a file. If it is there, just continue the code. If it has not arrived, continue cheking for a given amount of time, or untill the file shows up. My loop works on its own, so when i only select the do-part in Powershell ISE, it works. But when i try running it inside the if statement, nothing happens. The loops doesnt begin.
$exists= Test-Path $resultFile
$a = 1
if ($exists -eq "False")
{
do
{
$a++
log "Now `$a is $a "
start-sleep -s ($a)
$exists= Test-Path $resultFile
write-host "exists = $exists"
}
while (($a -le 5) -and ($exists -ne "True"))
}
Another way of doing this is using a while loop:
$VerbosePreference = 'Continue'
$file = 'S:\myFile.txt'
$maxRetries = 5; $retryCount = 0; $completed = $false
while (-not $completed) {
if (Test-Path -LiteralPath $file) {
Write-Verbose "File '$file' found"
$completed = $true
# Do actions with your file here
}
else {
if ($retryCount -ge $maxRetries) {
throw "Failed finding the file within '$maxRetries' retries"
} else {
Write-Verbose "File not found, retrying in 5 seconds."
Start-Sleep '5'
$retryCount++
}
}
}
Some tips:
Try to avoid Write-Host as it kills puppies and the pipeline (Don Jones). Better would be, if it's meant for viewing the script's progress, to use Write-Verbose.
Try to be consistent in spacing. The longer and more complex your scripts become, the more difficult it will be to read and understand them. Especially when others need to help you. For this reason, proper spacing helps all of us.
Try to use Tab completion in the PowerShell ISE. When you type start and press the TAB-key, it will automatically propose the options available. When you select what you want with the arrow down/up and press enter, it will nicely format the CmdLet to Start-Sleep.
The most important tip of all: keep exploring! The more you try and play with PowerShell, the better you'll get at it.
As pointed out in comments, your problem is that you're comparing a boolean value with the string "False":
$exists -eq "False"
In PowerShell, comparison operators evaluate arguments from left-to-right, and the type of the left-hand argument determines the type of comparison being made.
Since the left-hand argument ($exists) has the type [bool] (a boolean value, it can be $true or $false), PowerShell tries to convert the right-hand argument to a [bool] as well.
PowerShell interprets any non-empty string as $true, so the statement:
$exists -eq "False"
is equivalent to
$exists -eq $true
Which is probably not what you intended.
im curious how to use the IF statement logic further in my code. Let me elaborate with an example.
$a=1
$b=10000
if(($a=1) -or ($b=1))
{write-host ""} #Here, I want to write what ever variable was $true
#in the if statement above.... so I want it to
#write "1" which was $a and was $true in the if
#statement...
I could write more logic to accomplish this, but im wondering if the values that the if statement used can be used again in the code. Im thinking there is a "hidden" variable maybe?
($a=1) is usually an assignment statement. This is not the case in Powershell, but it sure looks like a bug. The Powershell way to do comparison is to use -eq. So,
if(($a -eq 1) -or ($b -eq1))
Now, the simple solution is a bit different. What happens, if both $a and $b happen to be 1?
$comp = 1 # Value to compare against
$a=1
$b=100
if($a -eq $comp) { write-host "`$a: $a" }
if($b -eq $comp) { write-host "`$b: $b" }
This approach is easy to understand, which is in most of the cases more important than other factors like speed.