Birth of a Script/Function
I know my post have been few and far between, but I have been super swamped at work and will be for a few more months at least.
That said I am writing some scripts and functions for work and as I was writing one today I though maybe I should share how I go about writing a function slash script. I like step-by-step lists so I decided at that format.
1> A purpose
- All Scripts must start with a purpose. Be it install something or check something. It needs to do something.
2> I figure the best process to do what I want
- Can what I want done be remoted?
- Do I use WMI?
- Do I use .NET?
- Do I use external Commands?
- Who is going to be doing it? What rights do they need?
- Does it have potential to break stuff (BIGGY!!!)
3> Write a function or functions that do what I want done on one Server, Device, or file
Example
Param($srv,$ptch)
$hf = get-WmiObject Win32_QuickfixEngineering -ComputerName $srv | where-Object{$_.HotfixID -match $ptch}
if($hf)
{
return $true
}
else
{
return $false
}
}
4> Cut and Paste function into my templates (At the bottom of post)
- Add any missing parameters
- Add any extra parsing
- Add error control if needed
5> Now it looks like this
Param([string]$server,[string]$hotfix)
Begin{
function PingServer {
param([string]$srv)
$pingresult = Get-WmiObject win32_pingstatus -f "address=’$srv’"
if($pingresult.statuscode -eq 0) {$true} else {$false}
}
function Checkhf{
Param($srv,$ptch)
$hf = get-WmiObject Win32_QuickfixEngineering -ComputerName $srv | where-Object{$_.HotfixID -match $ptch}
if($hf)
{
return $true
}
else
{
return $false
}
}
Write-Host
$process = @()
}
Process{
if($_)
{
if($_.ServerName)
{
$process += $_.ServerName
}
else
{
$process += $_
}
}
}
End{
if($Server){$Process += $Server}
if($process.Length -eq 0){$Process += get-content env:COMPUTERNAME}
foreach($s in $process)
{
if(PingServer $s)
{
$myobj = "" | select-Object Server,Result
$myobj.Server = $s
$myobj.Result = Checkhf -srv $s -ptch $hotfix
Write-Output $myObj
}
}
}
}
6> Final Test
Here are my Templates
- By default they take a Pipe, Server, or File and will process all three
Template for Script
Begin{
function PingServer {
param($srv)
$pingresult = Get-WmiObject win32_pingstatus -f "address=’$srv’"
if($pingresult.statuscode -eq 0) {$true} else {$false}
}
function InsertFunctionHere{
}
Write-Host
$process = @()
}
Process{
if($_)
{
if($_.ServerName)
{
$process += $_.ServerName
}
else
{
$process += $_
}
}
}
End{
# Check if $server is populated and add to Process Array
if($Server){$Process += $Server}
# Check if $file is populated and add to Process Array
if($file)
{
foreach($entry in (get-content $file))
{
$Process += $entry
}
}
# If Process Array is empty… Add self
if($process.Length -eq 0){$Process += get-content env:COMPUTERNAME}
foreach($s in $process)
{
if(pingserver $s)
{
InsertFunctionHere $s
}
Write-Host
}
}
Template for Function
Param([string]$server,[string]$file)
Begin{
function PingServer {
param($srv)
$pingresult = Get-WmiObject win32_pingstatus -f "address=’$srv’"
if($pingresult.statuscode -eq 0) {$true} else {$false}
}
function InsertFunctionHere{
}
Write-Host
$process = @()
}
Process{
if($_)
{
if($_.ServerName)
{
$process += $_.ServerName
}
else
{
$process += $_
}
}
}
End{
# Check if $server is populated and add to Process Array
if($Server){$Process += $Server}
# Check if $file is populated and add to Process Array
if($file)
{
foreach($entry in (get-content $file))
{
$Process += $entry
}
}
# If Process Array is empty… Add self
if($process.Length -eq 0){$Process += get-content env:COMPUTERNAME}
foreach($s in $process)
{
if(pingserver $s)
{
InsertFunctionHere $s
}
Write-Host
}
}
}
tshell :: Apr.24.2007 :: HowTo, Powershell, functions :: No Comments »
Hi, can you explain this construct for me?
myobj = “” | select-Object Server,Result