Store Filename as separate variables in PowerShell - based on specific character - powershell

Question

I have a vendor file that is stored in a specific format and I would like to use PowerShell to convert the file name into three separate variables which I would then use to pass to a stored procedure that would be executed.
The file format would look like:
AA_BBBBB_YYYYMMDD.xlsx
For instance, the following is an example of a current Excel file:
TX_StampingFee_20210303.xlsx
The 1st characters will generally be a US state abbreviation but not always - so it could be 2 or 3 characters long. The 2nd section is the type of fee the Excel file contains while the last section is the date in a YYYYMMDD format.
What I would like to do is have PowerShell read the file name and separate the name into three separate variables:
$State
$Fee
$Date
What I have so far will list the Excel file in the directory and then I tried to split the name up - but I believe the file extension on the name is causing an error. How can I split this file name into separate variables based off the "_" ( underscore ) character?
Foreach ($file in Get-Childitem "C:\PowerShell\Test\*.xlsx") {
$file.name
}
$filenames = (Get-ChildItem -Path "C:\PowerShell\Test\*.xlsx" -Directory).Name
Write-Host $filenames
$chararray = $filenames.Split("_")
$chararray

Answer 1

You can target the basename which is the filename minus the extension. Then when you split into 3 parts you can directly put those into 3 variables.
Foreach ($file in Get-Childitem "C:\PowerShell\Test\*.xlsx") {
$State,$Fee,$Date = $file.basename.split('_')
Write-Host State: $State Fee: $Fee Date: $Date
}

Answer 2

Use BaseName rather than the Name property to get the filename without the extension.
Then, if you trust the pattern of the filenames, you can index into your array with a range to join your 1+ fee type substrings into a single string:
$filenames = (Get-ChildItem -Path "C:\PowerShell\Test\*.xlsx" -File).BaseName
if ($filenames) {
[System.Collections.ArrayList]$fees = #()
[System.Collections.ArrayList]$states = #()
[System.Collections.ArrayList]$dates = #()
foreach ($name in $filenames) {
$chararray = $name.Split("_")
$arrlen = $chararray.length
if ($arrlen -ge 3) {
$states += $chararray[0]
$fees += $chararray[1..$arrlen-2] -join '_'
$dates += $chararray[$arrlen])
}
}
}