Script Template with built-in Help and Argument Checking

$psScriptName = "MyScript.ps1"
$psScriptAuth = "Kahuna at PoshTips.com"
$psScriptDate = "11/18/2009"
##############################################################################
## MyScript.ps1 - powershell script template
##
## Original Script by Kahuna at PoshTips.com - 11/18/2009
##
## Maintenance (most recent updates at top):
## Date        By   Comments
## ----------  ---  ----------------------------------------------------------
## 11/18/2009  KPS  new script
##
##############################################################################
$scriptUsage = @"
==============================================================================
 SCRIPT  : $psScriptName
 AUTHOR  : $psScriptAuth
 VERSION : $psScriptDate
==============================================================================
 PURPOSE:
    powershell script to <decribe functionality here>
 
 USAGE:
 
    MyScript [hostname(s) | filename(s)][-OPTION1][-OPTION2][-?|-H]
 
    - From the PowerShell command-line, invoke the script, passing any combination
      of hostnames and filenames (text file(s) containing a hostname listing
    - Any combinations and number of arguments can be used
    - if an argument is a filename:
         - each line in the file will processed as a hostname
         - any lines starting with `# will be treated as comments and ignored
    - if an argument is not a filename:
         - the argument will processed as a hostname
  FLAGS:
    -OPTION1  = Describe option here or remove
    -OPTION2  = Describe option here or remove
    -? or -H  = Display this help
 
  EXAMPLES:
              ./MyScript server1 hostlist.txt server2 server3 -OPTION1 -OPTION2
 
              ./MyScript host1 host2 host2
 
==============================================================================
"@
 
Set-PSDebug -Trace 0
$script:recCount = 0
 
function ShowUsage([string]$message=""){
	$message
	$scriptUsage
	exit
	}
 
function DoSomething([string]$hostName) {
    #Here is where you will do some work with $hostname parameter
    ++$script:recCount;
    "$script:recCount,$hostName"
	}
 
######################################################
## MAIN
######################################################
if ($args.count)
	{
    # Process command-line flags
	foreach ($item in $args)
		{
		if ($item -like "-*")
			{
			switch ($item)
				{
				"-OPTION1"
					{
					#setup this option here or in a new function
					}
				"-OPTION2"
					{
					#setup this option here or in a new function
					}
				"-H" {ShowUsage;}
				"-?" {ShowUsage;}
				default {ShowUsage "ERROR: $item is invalid!";}
				}
            }
        }
    # Write the CSV header
    "LN,HostName"
    # Process non-flag arguments
	foreach ($item in $args) {
        if ($item -notlike "-*") {
 
	        # if argument is filename: process file contents
	        if (test-path($item))
	        	{
			    foreach ($hostname in get-content $item)
			    	{
				    $hostname = $hostname.trim()
				    if ($hostname -notlike "#*") {
					    DoSomething $hostname
		   			    }
	    		    }
	            }
 
            # else treat as hostname
            else
            	{
                DoSomething($item)
                }
            }
        }
    }
else
	{
	ShowUsage "ERROR: This script requires arguments"
	}