[DJ Mogarych]

Powershell

Код:

$file = 'C:\Temp\1.txt'

$content = gc $file |
group {$_ -replace '.*/(.+)\..+?$','$1'} |% {
    if ($_.count -eq 1) {
        $_.group
    }
    else {
        if ($_.group -match 'mp4$') {($_.group -match 'mp4$')[-1]}
        else {($_.group)[-1]}
    }
}

Set-Content -Path $file -Value $content