Powershell Rename Multiple Files with LastWriteTime Prefix
This script should do exactly what you want
- Search recursively from a root directory
- Exclude files with existing "yyyyMMdd " file name prefix
- Rename the files not excluded above with ""yyyyMMdd " file name prefix based on their specific LastWriteTime
Warning: You should test this script first because renaming could be dangerous. Remove the #
in front of Rename-Item
after you have verified that only intentional files will be renamed.
Long version
$folder = "C:\somefolder"
$files = get-childitem -path $folder -recurse | where { -not $_.PSIsContainer }
[datetime]$dirDate = New-Object DateTime
foreach ($file In $files) {
$strDate = $file.Name.substring(0,8)
if (-Not [DateTime]::TryParseExact($strDate, "yyyyMMdd",
[System.Globalization.CultureInfo]::InvariantCulture,
[System.Globalization.DateTimeStyles]::None, [ref]$dirDate)) {
$newName = $file.lastwritetime.tostring("yyyyMMdd ") + $file.name
echo $newName
#Rename-Item -path $file.Fullname -newname $newName
}
}
Short version
[datetime]$dirDate = New-Object DateTime
dir "C:\somefolder" -r | ? { ! $_.PSIsContainer } | % {
if ( ! [DateTime]::TryParseExact($_.Name.substring(0,8), "yyyyMMdd",
[System.Globalization.CultureInfo]::InvariantCulture,
[System.Globalization.DateTimeStyles]::None, [ref]$dirDate)) {
$newName = $_.lastwritetime.tostring("yyyyMMdd ") + $_.name
echo $newName
#Ren $_.Fullname $newName
}
}
Used stackoverflow answers
[DateTime]::TryParseExact
to test if the first 8 characters can be a valid date$_.lastwritetime.tostring("yyyyMMdd ")
to format the lastwrite stamp