Version strings to "System.Version" too long (or short) in PowerShell-CodePudding

How can I force conversion to type System.Version in PowerShell, or more likely, better understand why I cannot arbitrarily assign number strings type System.Version?

We ingest some software updates in folders whose titles include version numbers. In trying to get reports on what the latest versions ingested are, I have been doing the following quick and dirty:

ForEach ($Folder in $(Get-ChildItem -Path $SoftwareDirectory -Directory))
{
    $CurrentVersion = $Folder -Replace "[^0-9.]"
    If ($CurrentVersion -ne $null)
    {
        If ([System.Version]$CurrentVersion -gt [System.Version]$MaxVersion)
        {
            $MaxVersion = $CurrentVersion
            $MaxFolder = $Folder
        }
    }
}

This would be fed directory titles like the following,

foo-tools-1.12.file
bar-static-3.4.0.file

Most of the time, this is acceptable. However, when encountering some oddballs with longer numbers, like the following,

applet-4u331r364.file

In which case, System.Version refuses the resulting string as being too long.

Cannot convert value "4331364" to type "System.Version". Error: "Version string portion was too short or too long."

CodePudding user response：

You need to ensure that your version strings have at least two components in order for a cast to [version] to succeed:

(
  @(
    'oo-tools-1.12.file'
    'bar-static-3.4.0.file'
    'applet-4u331r364.file'
  ) -replace '[^0-9.]'
).TrimEnd('.') -replace '^[^.] $', '$&.0' | ForEach-Object { [version] $_ }

The above transforms 'applet-4u331r364.file' into '4331364.0', which works when cast to [version].

Note that you can avoid the need for .TrimEnd('.') if you exclude the filename extension to begin with: $Folder.BaseName -replace '[^0-9.]'

-replace '^[^.] $', '$&.0' matches only strings that contain no . chars., in full, i.e. only those that don't already have at least two components; replacement expression $&.0 appends literal .0 to the matched string ($&).

Output (via Format-Table -AutoSize):

Major   Minor Build Revision
-----   ----- ----- --------
1       12    -1    -1
3       4     0     -1
4331364 0     -1    -1