How To: Find what PowerShell Functions are in what files and/or modules

As you create larger and larger PowerShell scripts, developing the habit of organizing them into separate files and modules is important for two reasons. Managing complexity and maintaining the ability to reason about what you’ve built.

One system I wrote contained:

• 105 PowerShell script files
• 151 functions
• Over 4 KLOCs (read Kay-Locks, meaning 4,000 lines of code). 

Compared to the PowerShell Pack WPK set of scripts having:

• 73 files
• 722 functions
• More than 100 KLOCs

Maybe you keep your scripts in separate directory and each are for a different task.

Select-String – Finds text in strings and files

While Select-String is a useful and must know cmdlet, if searching for a function name you will find that name when it is contained in a comment or random string. Sometimes you don’t want to see that.

Get-Function Finds and Returns Only Function Names

Get-Function searches all PowerShell files from the current directory and returns only function names. Plus, you can provide a partial name and Get-Function will do a match. The following output is the result of running Get-Function in the $PSHOME\Modules\PSDiagnostics directory.

FunctionName                 FileName                     Line
------------                 --------                     ----
Start-Trace                  C:\Windows\System32\Wind...    20
Stop-Trace                   C:\Windows\System32\Wind...    96
Enable-WSManTrace            C:\Windows\System32\Wind...   122
Disable-WSManTrace           C:\Windows\System32\Wind...   152
Enable-PSWSManCombinedTrace  C:\Windows\System32\Wind...   157
Disable-PSWSManCombinedTrace C:\Windows\System32\Wind...   179
Set-LogProperties            C:\Windows\System32\Wind...   184
ConvertTo-Bool               C:\Windows\System32\Wind...   223
Get-LogProperties            C:\Windows\System32\Wind...   235
Enable-PSTrace               C:\Windows\System32\Wind...   262
Disable-PSTrace              C:\Windows\System32\Wind...   269

The Script

Get-Function recursively searches from the current directory (the default that can be overridden), then uses the PowerShell tokenizer (see line 8 ) to select only script statements that are functions and returns the name of that function (see lines 13 and 14). It creates and emits to the pipeline a PSObject that holds the FileName, FunctionName and Line Number. Finally, the where cmdlet is used to filter only the function names you’d like, if provided.

As with other PowerShell output, the results from Get-Function can be saved to a file, piped to Out-GridView or piped to other cmdlets like Group-Object.

Function Get-Function ($pattern, $path="$pwd") {            
             
 $parser  = [System.Management.Automation.PSParser]            
             
 Get-ChildItem $path -Recurse -Include *.ps1, *.psm1 | ForEach {             
             
   $content = [IO.File]::ReadAllText($_.FullName)            
   $tokens  = $parser::Tokenize($content, [ref] $null)            
   $count   = $tokens.Count             
                   
   $(            
       for($idx=0; $idx -lt $count; $idx += 1) {            
            if($tokens[$idx].Content -eq 'function') {            
                $targetToken = $tokens[$idx+1]            
                New-Object PSObject -Property @{            
                   FileName = $_.FullName            
                   FunctionName = $targetToken.Content             
                   Line = $targetToken.StartLine            
                } | Select FunctionName, FileName, Line            
            }            
       }             
   ) | Where {$_.FunctionName -match $pattern}            
 }            
}