How to parse through folders and files using PowerShell? - powershell

Question

I am trying to construct a script that moves through specific folders and the log files in it, and filters the error codes. After that it passes them into a new file.
I'm not really sure how to do that with for loops so I'll leave my code bellow.
If someone could tell me what I'm doing wrong, that would be greatly appreciated.
$file_name = Read-Host -Prompt 'Name of the new file: '
$path = 'C:\Users\user\Power\log_script\logs'
Add-Type -AssemblyName System.IO.Compression.FileSystem
function Unzip
{
param([string]$zipfile, [string]$outpath)
[System.IO.Compression.ZipFile]::ExtractToDirectory($zipfile, $outpath)
}
if ([System.IO.File]::Exists($path)) {
Remove-Item $path
Unzip 'C:\Users\user\Power\log_script\logs.zip' 'C:\Users\user\Power\log_script'
} else {
Unzip 'C:\Users\user\Power\log_script\logs.zip' 'C:\Users\user\Power\log_script'
}
$folder = Get-ChildItem -Path 'C:\Users\user\Power\log_script\logs\LogFiles'
$files = foreach($logfolder in $folder) {
$content = foreach($line in $files) {
if ($line -match '([ ][4-5][0-5][0-9][ ])') {
echo $line
}
}
}
$content | Out-File $file_name -Force -Encoding ascii
Inside the LogFiles folder are three more folders each containing log files.
Thanks

Answer 1

Expanding on a comment above about recursing the folder structure, and then actually retrieving the content of the files, you could try something line this:
$allFiles = Get-ChildItem -Path 'C:\Users\user\Power\log_script\logs\LogFiles' -Recurse
# iterate the files
$allFiles | ForEach-Object {
# iterate the content of each file, line by line
Get-Content $_ | ForEach-Object {
if ($_ -match '([ ][4-5][0-5][0-9][ ])') {
echo $_
}
}
}

Answer 2

It looks like your inner loop is of a collection ($files) that doesn't yet exist. You assign $files to the output of a ForEach(...) loop then try to nest another loop of $files inside it. Of course at this point $files isn't available to be looped.
Regardless, the issue is you are never reading the content of your log files. Even if you managed to loop through the output of Get-ChildItem, you need to look at each line to perform the match.
Obviously I cannot completely test this, but I see a few issues and have rewritten as below:
$file_name = Read-Host -Prompt 'Name of the new file'
$path = 'C:\Users\user\Power\log_script\logs'
$Pattern = '([ ][4-5][0-5][0-9][ ])'
if ( [System.IO.File]::Exists( $path ) ) { Remove-Item $path }
Expand-Archive 'C:\Users\user\Power\log_script\logs.zip' 'C:\Users\user\Power\log_script'
Select-String -Path 'C:\Users\user\Power\log_script\logs\LogFiles\*' -Pattern $Pattern |
Select-Object -ExpandProperty line |
Out-File $file_name -Force -Encoding ascii
Note: Select-String cannot recurse on its own.
I'm not sure you need to write your own UnZip function. PowerShell has the Expand-Archive cmdlet which can at least match the functionality thus far:
Expand-Archive -Path <SourceZipPath> -DestinationPath <DestinationFolder>
Note: The -Force parameter allows it to over write the destination files if they are already present. which may be a substitute for testing if the file exists and deleting if it does.
If you are going to test for the file that section of code can be simplified as:
if ( [System.IO.File]::Exists( $path ) ) { Remove-Item $path }
Unzip 'C:\Users\user\Power\log_script\logs.zip' 'C:\Users\user\Power\log_script'
This is because you were going to run the UnZip command regardless...
Note: You could also use Test-Path for this.
Also there are enumerable ways to get the matching lines, here are a couple of extra samples:
Get-ChildItem -Path 'C:\Users\user\Power\log_script\logs\LogFiles' |
ForEach-Object{
( Get-Content $_.FullName ) -match $Pattern
# Using match in this way will echo the lines that matched from each run of
# Get-Content. If nothing matched nothing will output on that iteration.
} |
Out-File $file_name -Force -Encoding ascii
This approach will read the entire file into an array before running the match on it. For large files it may pose a memory issue, however it enabled the clever use of -match.
OR:
Get-ChildItem -Path 'C:\Users\user\Power\log_script\logs\LogFiles' |
Get-Content |
ForEach-Object{ If( $_ -match $Pattern ) { $_ } } |
Out-File $file_name -Force -Encoding ascii
Note: You don't need the alias echo or its real cmdlet Write-Output

Answer 3

UPDATE: After fuzzing around a bit and trying different things I finally got it to work.
I'll include the code below just for demonstration purposes.
Thanks everyone
$start = Get-Date
"`n$start`n"
$file_name = Read-Host -Prompt 'Name of the new file: '
Out-File $file_name -Force -Encoding ascii
Expand-Archive -Path 'C:\Users\User\Power\log_script\logs.zip' -Force
$i = 1
$folders = Get-ChildItem -Path 'C:\Users\User\Power\log_script\logs\logs\LogFiles' -Name -Recurse -Include *.log
foreach($item in $folders) {
$files = 'C:\Users\User\Power\log_script\logs\logs\LogFiles\' + $item
foreach($file in $files){
$content = Get-Content $file
Write-Progress -Activity "Filtering..." -Status "File $i of $($folders.Count)" -PercentComplete (($i / $folders.Count) * 100)
$i++
$output = foreach($line in $content) {
if ($line -match '([ ][4-5][0-5][0-9][ ])') {
Add-Content -Path $file_name -Value $line
}
}
}
}
$end = Get-Date
$time = [int]($end - $start).TotalSeconds
Write-Output ("Runtime: " + $time + " Seconds" -join ' ')