Powershell - File name change Date-CodePudding

Suppose I have a daily date generated CSV file

Eg: File_1_20220321.CSV

How do I use Powershell to change the year to 2015 so the file name would be:

Eg: File_1_20150321.CSV

CodePudding user response：

If you automatically generate the date for the csv-File via

Get-Date -uformat "%m%d%Y"

which is the most logical way to do it for a clean formatting, you can simply add another parameter:

Get-Date -uformat "%m%d%Y" -year "2015"

Hence the way to export your log would be:

$dateold = Get-Date -uformat "%m%d%Y" -year "2015"    
Export-Csv -Path "C:\yourpath\filename_$dateold.csv" -InputObject $myobject

CodePudding user response：

To automate the renaming of the file with today's date in its name to have a date 7 years ago, you can do the following:

$today  = Get-Date
$filter = '*_{0:yyyyMMdd}.csv' -f $today
Get-ChildItem -Path 'X:\somewhere' -Filter $filter -File | 
    Rename-Item -NewName { $_.Name -replace "_$($today.Year)", "_$($today.AddYears(-7).Year)"} -WhatIf

I have added safety switch -WhatIf to the Rename-Item cmdlet.
This makes the command only show in the console what would happen and nothing actually gets renamed. Once you are satisfied the code will rename correctly, remove that -WhatIf switch and run again.

If the dates in the replacement need to be valid (like when today would be the 29th of Februari and changing the year to 7 years ago, you will end up with an invalid date), use this code:

$today        = Get-Date
$todayPattern = '{0:yyyyMMdd}'-f $today
$olderPattern = '{0:yyyyMMdd}'-f $today.AddYears(-7)
$filter       = '*_{0:yyyyMMdd}.csv' -f $today
Get-ChildItem -Path 'X:\somewhere' -Filter $filter -File | 
    Rename-Item -NewName { $_.Name -replace "_$todayPattern", "_$olderPattern"} -WhatIf