Powershell: Incrementing number while ignoring string tag

Question

this is my first stack question so go easy on me.

Currently working on a project to create a new folder on a network drive by incrementing off of the previous folders version number.

For example: 5.2.0.0110 -> 5.2.0.0111

Here is my current powershell solution that does the trick:

$SourceFolder = "\\corpfs1\setup\ProtectionSuite\Version 5.2.0.x\5.2.0.0001"
$DestinationFolder = "\\corpfs1\setup\ProtectionSuite\Version 5.2.0.x"
$msiSourceFolder = "\\SourceMsiPath"
$exeSourceFolder = "\\SourceExePath"
if (Test-Path $SourceFolder)
{
        $latest = Get-ChildItem -Path $DestinationFolder| Sort-Object Name -Descending | Select-Object -First 1 
        #split the latest filename, increment the number, then re-assemble new filename:
        $newFolderName = $latest.BaseName.Split('.')[0] + "." + $latest.BaseName.Split('.')[1] + "."+ $latest.BaseName.Split('.')[2] + "." + ([int]$latest.BaseName.Split('.')[3] + 1).ToString().PadLeft(4,"0")
        New-Item -Path $DestinationFolder"\"$newFolderName -ItemType Directory

        Copy-Item $msiSourceFolder -Destination $DestinationFolder"\"$newFolderName
        Copy-Item $exeSourceFolder -Destination $DestinationFolder"\"$newFolderName
}

However, one thing that this does not account for is version numbers with string at the end. This solution attempts to covert the string -> int which fails. Some of the folders have strings as they are for internal releases so there is no way to just change my naming semantics.

For example: 5.2.0.1234 (eng) -> 5.2.0.1235

I would like to ignore any text after the last four digits and increment as shown in the example above. If anyone has a suggestion I am all ears! Thank you.

Answer 1

Assuming that your folder names contain only one 4-digit sequence preceded by a ., it is simpler to match and replace only it, using the regular-expression-based -replace operator with a script block-based substitution:

Update:

• A later clarification revealed that the post-version suffix in the input string should be (b) removed from the output rather than (a) just ignored for the purpose of incrementing while getting preserved in the output - see the bottom section for a solution to (b).

---

SOLUTION (a): If the post-version suffix should be preserved:

In PowerShell (Core) v6.1+:

# Replace the sample value '5.2.0.1234 (eng)' with the following in your code:
#   $newFolderName = $latest.BaseName [-replace ...]
'5.2.0.1234 (eng)' -replace '(?<=\.)\d{4}', { '{0:0000}' -f  (1 + $_.Value) }

The above yields 5.2.0.1235 (eng) - note the incremented last version-number component and the preservation of the suffix.

In Windows PowerShell (versions up to 5.1), where script block-based substitutions aren't supported, direct use of the underlying .NET API is required:

[regex]::Replace('5.2.0.0110 (eng)', '(?<=\.)\d{4}', { '{0:0000}' -f  (1 + $args[0].Value) })

Explanation:

• (?<=\.)\d{4} is a regex (regular expression) that matches a literal . (\.) inside a look-behind assertion ((?<=...)), followed by 4 ({4}) digits (\d). The look-behind assertion ensures that the literal . isn't included in the text captured by the match.

• The script block ({ ... }) receives information about (each) match, as a System.Text.RegularExpressions.Match instance, via the automatic $_ variable in the PowerShell (Core) solution, via the automatic $args variable in the Windows PowerShell solution with the direct .NET call.

• The script block's output (return value) is used to replace the matched text:

  • '{0:0000}' -f ... uses -f, the format operator, to format the RHS with 4-digit 0-padding.

  • (1 + $_.Value) / (1 + $args[0].Value) adds 1 to the 4-digit sequence captured by the match, which is implicitly converted to a number due to the LHS of the + operation being a number.

---

SOLUTION (b): If the post-version suffix should be removed:

In PowerShell (Core) v6.1+:

'5.2.0.1234 (eng)' -replace '\.(\d{4}).*', { '.{0:0000}' -f  (1 + $_.Groups[1].Value) }

The above yields 5.2.0.1235 - note the incremented last version-number component and the absence of the suffix.

In Windows PowerShell:

[regex]::Replace('5.2.0.1234 (eng)', '\.(\d{4}).*', { '.{0:0000}' -f  (1 + $args[0].Groups[1].Value) })

Answer 2

You can do:

$version = ($latest.BaseName -replace '^((?:\d+\.){3}\d{4}).*', '$1').Split('.')
$version[-1] = '{0:D4} -f ([int]$version[-1] + 1)
$newFolderName = $version -join '.'

# '5.2.0.0110 (eng)' --> '5.2.0.0111'

---

As per your comment, you should use Join-Path for constructing the full target path:

$targetPath = Join-Path -Path $DestinationFolder -ChildPath $newFolderName
$null = New-Item -Path $targetPath -ItemType Directory -Force

Copy-Item $msiSourceFolder -Destination $targetPath
Copy-Item $exeSourceFolder -Destination $targetPath