Powershell novice looking to create script to trigger notifications on missing files - powershell

Question

Long time lurker first time poster. I'm looking(of my own initiative) to see if there is a method by which I can check for missing files, that we would expect to receive on a daily basis, and be notified via e-mail.
Our company has what I'd call a relatively unhinged systems infrstructure, that since I arrived I've been chipping away here and there putting in some practices and process' to be more proactive with our monitoring.
Specifically in this case, we receive files via FTP from a vendor, that outlines our Sales and other data. These files go through some validation and the data is then imported into our ERP platform. However I am interested to put in a check, that raises and alert when a file has not been received, when expected.
The last part of that requirement can potentially change, I'm not sure how specific I can get when trying to raise an alert from an expected file.
I'll outline this by stating I'm a relative novice in this area, but there is really no one in my department any the wiser. So I've been looking into powershell.
I've created the following two bits of codes so far, that when executed appear to return files that have been created/last writ, within the last day. This would even be enough, to have this output sent via e-mail. I would be able to spot quickly if an expected file is not in the list.
GET-ChildItem -Path "Path I am checking" |
Where-Object {$_.LastWritetime -gt (get-Date).AddDays(-1)}
The above returns one .csv file. I guess if I get a returned file, then I know its been provided, and if the return is blank/zero, then I know I didn't get a file.
I've used the above for four seperate checks, checking other subfolders in the structure.
To outline the folder structure
\"App server"\"Region"\"Vendor"
There are then the following subfolders
Purchases
Sales
Tenders
VAT
Each of the above four folders then has
Incoming
Processed
I am running my checks on the processed folder for each of the four folder outlined above.

Answer 1

Maybe something like this will help you out:
Function Test-NewerFiles {
# We use parameters as it makes things easy when we need to change things
# CmdLetBinding makes sure that we can see our 'Write-Verbose' messages if we want to
[CmdLetBinding()]
Param (
[String]$Path = 'C:\Users\me\Downloads\Input_Test',
[String]$ExportFile = 'C:\Users\me\Downloads\Log_Test\Attachment.txt'
)
# We first save the date, then we don't need to do this every time again
$CompareDate = (Get-Date).AddDays(-1)
# Then we collect only the folders and check each folder for files and count them
Get-ChildItem -Path $Path -Directory -Recurse | ForEach-Object {
$Files = (Get-ChildItem -Path $_.FullName -File | Where-Object {$_.LastWritetime -gt $CompareDate} | Measure-Object).Count
# If we didn't find files the count is 0 and we report this
if ($Files -eq 0) {
Write-Verbose "No files found in folder $($_.FullName)"
Write-Output $_.FullName
}
# If we found files it's ok and we don't report it
else {
Write-Verbose "Files found in folder $($_.FullName)"
}
}
}
# If you don't want to see output you can remove the '-Verbose' switch
Test-NewerFiles -Verbose
$MyNewFiles = Test-NewerFiles
$MyNewFiles | Out-File -FilePath $ExportFile -Encoding utf8
if ($MyNewFiles) {
$MailParams = #{
To = 'Chuck.Norris#world.com'
From = 'MyScriptServer#world.com'
SmtpServer = 'SMTPServer'
}
Send-MailMessage #MailParams -Priority High -Attachments $ExportFile -Body 'We found problems: check attachment for details'
}
else {
Send-MailMessage #MailParams -Priority Low -Body 'All is ok'
}
The Verbose switch is only used to report progress. So we can see what it does when it's running. But when we use this code in production, we don't need these messages and just use Test-NewerFiles instead of Test-NewerFiles -Verbose.