Adding objects to an array in a hashtable - arrays

I want to create a Hashtable which groups files with the same name in arrays so I can later on work with those to list some properties of those files, like the folders where they're stored.
$ht = #{}
gci -recurse -file | % {
try{
$ht.Add($_.Name,#())
$ht[$_.Name] += $_
}
catch{
$ht[$_.Name] += $_
}
}
All I'm getting is:
Index operation failed; the array index evaluated to null.
At line:8 char:13
+ $ht[$_.Name] += $_
+ ~~~~~~~~~~~~~~~~~~
I'm not sure why this isn't working, I'd appreciate any help.

Don't reinvent the wheel. You want to group files with the same name, use the Group-Object cmdlet:
$groupedFiles = Get-ChildItem -recurse -file | Group-Object Name
Now you can easy retrieve all file names that are present at least twice using the Where-Object cmdlet:
$groupedFiles | Where-Object Count -gt 1
You are getting this error because if your code hits the catch block, the current pipeline variable ($_) represents the last error and not the current item. You can fix that by either storing the current item an a variable, or you use the -PipelineVariable advanced cmdlet parameter:
$ht = #{}
gci -recurse -file -PipelineVariable item | % {
try{
$ht.Add($item.Name,#())
$ht[$item.Name] += $item
}
catch{
$ht[$item.Name] += $item
}
}

Related

Iterate through Rows in SQL to Output to Text File

I have a SQL table that contains several hundred rows of data. One of the columns in this table contains text reports that were stored as plain text within the column.
Essentially, I need to iterate through each row of data in SQL and output the contents of each row's report column to its own individual text file with a unique name pulled from another column.
I am trying to accomplish this via PowerShell and I seem to be hung up. Below is what I have thus far.
foreach ($i=0; $i -le $Reports.Count; $i++)
{
$SDIR = "C:\harassmentreports"
$FILENAME = $Reports | Select-Object FILENAME
$FILETEXT = $Reports | Select-Object TEXT
$NAME = "$SDIR\$FILENAME.txt"
if (!([System.IO.File]::Exists($NAME))) {
Out-File $NAME | Set-Content -Path $FULLFILE -Value $FILETEXT
}
}
Assuming that $Reports is a list of the records from your SQL query, you'll want to fix the following issues:
In an indexed loop use indexed access to the elements of your array:
$FILENAME = $Reports[$i] | Select-Object FILENAME
$FILETEXT = $Reports[$i] | Select-Object TEXT
Define variables outside the loop if their value doesn't change inside the loop:
$SDIR = "C:\harassmentreports"
foreach ($i=0; $i -le $Reports.Count; $i++) {
...
}
Expand properties if you want to use their value:
$FILENAME = $Reports[$i] | Select-Object -Expand FILENAME
$FILETEXT = $Reports[$i] | Select-Object -Expand TEXT
Use Join-Path for constructing paths:
$NAME = Join-Path $SDIR "$FILENAME.txt"
Use Test-Path for checking the existence of a file or folder:
if (-not (Test-Path -LiteralPath $NAME)) {
...
}
Use either Out-File
Out-File -FilePath $NAME -InputObject $TEXT
or Set-Content
Out-File -Path $NAME -Value $TEXT
not both of them. The basic difference between the two cmdlets is their default encoding. The former uses Unicode, the latter ASCII encoding. Both allow you to change the encoding via the parameter -Encoding.
You may also want to reconsider using a for loop in the first place. A pipeline with a ForEach-Object loop might be a better approach:
$SDIR = "C:\harassmentreports"
$Reports | ForEach-Object {
$file = Join-Path $SDIR ($_.FILENAME + '.txt')
if (-not (Test-Path $file)) { Set-Content -Path $file -Value $_.TEXT }
}

Comparing AD users with File Names

I'm trying to find files that are named after members of a specific AD group with a foreach loop using the code below. The script seems to have a problem which causes the loop to stop after the first exception. I think I need to throw the exception because there seems to be no default return value or error if no file for one of the group members is found.
$ErrorActionPreference = "Stop"
$BVAU = Get-ADGroupMember ADGroupName | Select-Object -Property Name
foreach($entry in $BVAU) {
trap [System.IO.DirectoryNotFoundException]{
Write-Host $_.Exception.Message
continue
}
}
if (-not (Get-ChildItem "\\samplepath" -Recurse | Where-Object FullName -like "*$entry*")) {
throw [System.IO.DirectoryNotFoundException] "$entry not found"
}
}
I only want to display the group members that don't have an equally named file. (A PDF form that legally qualifies the AD group membership)
The if statement belongs inside the loop, and the trap should be defined before the loop. However, you don't need the trap in the first place, because it's pointless to throw exceptions just for echoing a username. Simply echo the name right away and continue. Also, avoid running code multiple times if it doesn't need to.
$files = Get-ChildItem "\\samplepath" -Recurse |
Select-Object -Expand Basename -Unique
Get-ADGroupMember ADGroupName |
Select-Object -Expand Name |
Where-Object { $files -notcontains $_ } |
ForEach-Object { "$_ not found" }
The above is assuming that the usernames aren't just partial matches of the file basenames. Otherwise the Where-Object filter becomes slightly more complicated:
...
Where-Object { $n = $_; -not ($files | Where-Object {$_ -like '*$n*'}) } |
...

Can't access values in an array that's part of a foreach loop in powershell

I'm relatively new to powershell and coding and am having issues accessing the values in an array. I'm trying to loop thru a set of files using foreach and count the number of messages in each file. And then have the count for each file put in to an array so I can assign it to a variable. When I do write-host $data[0] it returns all the values. If I do write-host $data1 it returns nothing. It seems like these values are all being stored as one instead of as individual numbers. How do I get each value and then assign it to a variable. Any help would be appreciated.
$FilePath = 'some file path here'
$TodaysDate = (Get-Date -format "MM-dd-yyyy")
ForEach($file in Get-ChildItem $FilePath -exclude *.ps1,*.xml,*.xls | Where-Object {$_.LastWriteTime -ge $TodaysDate})
{
$data = ,#(Get-Content $file | Where-Object {$_.Contains("MSH|")}).Count
write-host $data[0]
}
exit
powershell result
In this line:
$data = ,#(Get-Content $file | Where-Object {$_.Contains("MSH|")}).Count
you are creating an array of a single element (the count). What you want to do is add to $data each time:
$data += ,#(Get-Content $file | Where-Object {$_.Contains("MSH|")}).Count
But given your description, I think you may want a hashtable, using the filename as a key:
$data = #{} #init hashtable
ForEach($file in Get-ChildItem $FilePath -exclude *.ps1,*.xml,*.xls | Where-Object {$_.LastWriteTime -ge $TodaysDate})
{
$data[$file] = #(Get-Content $file | Where-Object {$_.Contains("MSH|")}).Count
}
write-output $data

One element containing hashes instead of multiple elements - how to fix?

I am trying to parse robocopy log files to get file size, path, and date modified. I am getting the information via regex with no issues. However, for some reason, I am getting an array with a single element, and that element contains 3 hashes. My terminology might be off; I am still learning about hashes. What I want is a regular array with multple elements.
Output that I am getting:
FileSize FilePath DateTime
-------- -------- --------
{23040, 36864, 27136, 24064...} {\\server1\folder\Test File R... {2006/03/15 21:08:01, 2010/12...
As you can see, there is only one row, but that row contains multiple items. I want multiple rows.
Here is my code:
[regex]$Match_Regex = "^.{13}\s\d{4}/\d{2}/\d{2}\s\d{2}:\d{2}:\d{2}\s.*$"
[regex]$Replace_Regex = "^\s*([\d\.]*\s{0,1}\w{0,1})\s(\d{4}\/\d{2}\/\d{2}\s\d{2}:\d{2}:\d{2})\s(.*)$"
$MainContent = New-Object System.Collections.Generic.List[PSCustomObject]
Get-Content $Path\$InFile -ReadCount $Batch | ForEach-Object {
$FileSize = $_ -match $Match_Regex -replace $Replace_Regex,('$1').Trim()
$DateTime = $_ -match $Match_Regex -replace $Replace_Regex,('$2').Trim()
$FilePath = $_ -match $Match_Regex -replace $Replace_Regex,('$3').Trim()
$Props = #{
FileSize = $FileSize;
DateTime = $DateTime;
FilePath = $FilePath
}
$Obj = [PSCustomObject]$Props
$MainContent.Add($Obj)
}
$MainContent | % {
$_
}
What am I doing wrong? I am just not getting it. Thanks.
Note: This needs to be as fast as possible because I have to process millions of lines, which is why I am trying System.Collections.Generic.List.
I think the problem is that for what you're doing you actually need two foreach-object loops. Using Get-Content with -Readcount is going to give you an array of arrays. Use the -Match in the first Foreach-Object to filter out the records that match in each array. That's going to give you an array of the matched records. Then you need to foreach through that array to create one object for each record:
[regex]$Match_Regex = "^.{13}\s\d{4}/\d{2}/\d{2}\s\d{2}:\d{2}:\d{2}\s.*$"
[regex]$Replace_Regex = "^\s*([\d\.]*\s{0,1}\w{0,1})\s(\d{4}\/\d{2}\/\d{2}\s\d{2}:\d{2}:\d{2})\s(.*)$"
$MainContent =
Get-Content $Path\$InFile -ReadCount $Batch |
ForEach-Object {
$_ -match $Match_Regex |
ForEach-Object {
$FileSize = $_ -replace $Replace_Regex,('$1').Trim()
$DateTime = $_ -replace $Replace_Regex,('$2').Trim()
$FilePath = $_ -replace $Replace_Regex,('$3').Trim()
[PSCustomObject]#{
FileSize = $FileSize
DateTime = $DateTime
FilePath = $FilePath
}
}
}
You don't really need to use the collection as an accumulator, just output PSCustomObjects, and let them accumulate in the result variable.

How to remove item from an array in PowerShell?

I'm using Powershell 1.0 to remove an item from an Array. Here's my script:
param (
[string]$backupDir = $(throw "Please supply the directory to housekeep"),
[int]$maxAge = 30,
[switch]$NoRecurse,
[switch]$KeepDirectories
)
$days = $maxAge * -1
# do not delete directories with these values in the path
$exclusionList = Get-Content HousekeepBackupsExclusions.txt
if ($NoRecurse)
{
$filesToDelete = Get-ChildItem $backupDir | where-object {$_.PsIsContainer -ne $true -and $_.LastWriteTime -lt $(Get-Date).AddDays($days)}
}
else
{
$filesToDelete = Get-ChildItem $backupDir -Recurse | where-object {$_.PsIsContainer -ne $true -and $_.LastWriteTime -lt $(Get-Date).AddDays($days)}
}
foreach ($file in $filesToDelete)
{
# remove the file from the deleted list if it's an exclusion
foreach ($exclusion in $exclusionList)
{
"Testing to see if $exclusion is in " + $file.FullName
if ($file.FullName.Contains($exclusion)) {$filesToDelete.Remove($file); "FOUND ONE!"}
}
}
I realize that Get-ChildItem in powershell returns a System.Array type. I therefore get this error when trying to use the Remove method:
Method invocation failed because [System.Object[]] doesn't contain a method named 'Remove'.
What I'd like to do is convert $filesToDelete to an ArrayList and then remove items using ArrayList.Remove. Is this a good idea or should I directly manipulate $filesToDelete as a System.Array in some way?
Thanks
The best way to do this is to use Where-Object to perform the filtering and use the returned array.
You can also use #splat to pass multiple parameters to a command (new in V2). If you cannot upgrade (and you should if at all possible, then just collect the output from Get-ChildItems (only repeating that one CmdLet) and do all the filtering in common code).
The working part of your script becomes:
$moreArgs = #{}
if (-not $NoRecurse) {
$moreArgs["Recurse"] = $true
}
$filesToDelete = Get-ChildItem $BackupDir #moreArgs |
where-object {-not $_.PsIsContainer -and
$_.LastWriteTime -lt $(Get-Date).AddDays($days) -and
-not $_.FullName.Contains($exclusion)}
In PSH arrays are immutable, you cannot modify them, but it very easy to create a new one (operators like += on arrays actually create a new array and return that).
I agree with Richard, that Where-Object should be used here. However, it's harder to read.
What I would propose:
# get $filesToDelete and #exclusionList. In V2 use splatting as proposed by Richard.
$res = $filesToDelete | % {
$file = $_
$isExcluded = ($exclusionList | % { $file.FullName.Contains($_) } )
if (!$isExcluded) {
$file
}
}
#the files are in $res
Also note that generally it is not possible to iterate over a collection and change it. You would get an exception.
$a = New-Object System.Collections.ArrayList
$a.AddRange((1,2,3))
foreach($item in $a) { $a.Add($item*$item) }
An error occurred while enumerating through a collection:
At line:1 char:8
+ foreach <<<< ($item in $a) { $a.Add($item*$item) }
+ CategoryInfo : InvalidOperation: (System.Collecti...numeratorSimple:ArrayListEnumeratorSimple) [], RuntimeException
+ FullyQualifiedErrorId : BadEnumeration
This is ancient. But, I wrote these a while ago to add and remove from powershell lists using recursion. It leverages the ability of powershell to do multiple assignment . That is, you can do $a,$b,$c=#('a','b','c') to assign a b and c to their variables. Doing $a,$b=#('a','b','c') assigns 'a' to $a and #('b','c') to $b.
First is by item value. It'll remove the first occurrence.
function Remove-ItemFromList ($Item,[array]$List(throw"the item $item was not in the list"),[array]$chckd_list=#())
{
if ($list.length -lt 1 ) { throw "the item $item was not in the list" }
$check_item,$temp_list=$list
if ($check_item -eq $item )
{
$chckd_list+=$temp_list
return $chckd_list
}
else
{
$chckd_list+=$check_item
return (Remove-ItemFromList -item $item -chckd_list $chckd_list -list $temp_list )
}
}
This one removes by index. You can probably mess it up good by passing a value to count in the initial call.
function Remove-IndexFromList ([int]$Index,[array]$List,[array]$chckd_list=#(),[int]$count=0)
{
if (($list.length+$count-1) -lt $index )
{ throw "the index is out of range" }
$check_item,$temp_list=$list
if ($count -eq $index)
{
$chckd_list+=$temp_list
return $chckd_list
}
else
{
$chckd_list+=$check_item
return (Remove-IndexFromList -count ($count + 1) -index $index -chckd_list $chckd_list -list $temp_list )
}
}
This is a very old question, but the problem is still valid, but none of the answers fit my scenario, so I will suggest another solution.
I my case, I read in an xml configuration file and I want to remove an element from an array.
[xml]$content = get-content $file
$element = $content.PathToArray | Where-Object {$_.name -eq "ElementToRemove" }
$element.ParentNode.RemoveChild($element)
This is very simple and gets the job done.

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