Add date to filename after specific underscore/position

Question

Hello

Im trying to append a timestamp to filenames.
The files have specific pattern with underscores between characters.
This way : XXXXX_XXXXXX_XXXX_XXX.txt

I want the files to be renamed this way:
Adding a timestamp after the first underscore.
XXXXX_TIMESTAMP_XXXXXX_XXXX_XXX.txt

I can scope files with the same pattern and exclude the others.
However I dont get to append the timestamp variable in the right place.
Im lost with the regex I should use in the -replace parameters

Here is my script:

>     $date = Get-Date -Format yyyyMMddHHmmssffffff

>     

>     $Path = "C:\TEST"

>     Get-ChildItem -Filter *.txt $Path | Foreach-Object{   

>        $NewName = $_.Name -replace "(.*?)_(.*?)_(.*?)_(.*?).txt", "\(_*\)+$date.txt+\(.*\).*\(.*\)"

>        Write-Host $NewName

>        Rename-Item -Path $_.FullName -NewName $NewName

>     }

Im able to rename files with $date only. but cant get it working with putting $date after the first underscore and keeping the other characters before and after.
I guess the issue is in the regex format:
-replace "(.?)_(.?)(.*?)(.?).txt", "(_)+$date.txt+(.).(.*)"

Can someone help me out ?
Thank you for your time !

Answer 1

Whatever you're doing, you're doing it wrong. Your script, with my suggestion and a modification to the Get-ChildItem cmdlet, works.

$date = Get-Date -Format yyyyMMddHHmmssffffff

$Path = "C:\TEST"
Get-ChildItem -Path "$Path\*" -Filter *.txt -File | 
    ForEach-Object {  
        $parts = $_.Name -split "_" 
        if ($parts.count -eq 4){
            $newname = "{0}_{1}_{2}_{3}_{4}" -f $parts[0], $date, $parts[1], $parts[2], $parts[3]
            Write-Host $NewName
            Rename-Item -Path $_.FullName -NewName $NewName
        }
        else{
            Write-Host "Skipping file " $_.Name -ForegroundColor Yellow
        }
}

Answer 2

Sometimes a regex just isn't the best (or most understandable) way to get things done.

$x = "XXXXX_XXXXXX_XXXX_XXX.txt"
$date = Get-Date -Format yyyyMMddHHmmssffffff

$parts = $x -split "_"

if ($parts.count -eq 4){
    $newname = "{0}_{1}_{2}_{3}_{4}" -f $parts[0], $date, $parts[1], $parts[2], $parts[3]
}

Answer 3

Thank you for your reply Matheisen but it doesnt do anything.
I've added the Get-ChildItem to catch my txt files but it didnt work either.

Answer 4

Hello Mat,

I was off to answer you earlier...
Yes, indeed, I didnt explain the output and the script I used.
Removing the variable " $x = "XXXXX_XXXXXX_XXXX_XXX.txt" " and using Get-ChildItem was the way to go.
Now, with your recommandations, it works like a charm.
I wanted to thank you for your help !
I really appreciate
Have a nice day :)