Script Snippets
1. Create a Unique Folder Name
(From: “Hey PowerShell guy, how can I create a new folder using a name based on the current date”)
function Create-UniqueFolder([string]$path) {
md ($path + "\result_$((get-date).toString('yyyyMMddHHmmss'))")
}
2. Check if Script Runs on x86 or x64 Platform
(From: “What is the best way to program against PowerShells x64 vs x86 Variability”)
function Is-Wx64 {
return test-path (join-path $env:WinDir "SysWow64")
}
3. Locate an Assembly (in Known Path, such As GAC)
function Get-AssemblyPathByName([string]$name) {
return [System.Reflection.Assembly]::LoadWithPartialName($name).Location
}
4. Read XML File
$file = "XML file path"
[System.Xml.XmlDocument] $xd = new-object System.Xml.XmlDocument
$xd.load($file)
# ... for example ...
$xd.SelectSingleNode("/mynode").getAttribute("myattribute")
5. Replace All Occurrences of a String in File
function Replace-InFile([string]$file, [string]$find, [string]$replace) {
(Get-Content $file) | Foreach-Object {$_ -replace $find, $replace} | Set-Content $file
}
6. Handle a Process
Start a Process, Get Process Output and Standard Error Output, Wait for Process to Complete
# ... example doesn't load user profile, but redirects and retrieves stdout and stderr
$StartInfo = New-Object System.Diagnostics.ProcessStartInfo
$StartInfo.FileName = "process path and name"
$StartInfo.Arguments="process arguments, if any"
$StartInfo.LoadUserProfile = $false
$StartInfo.RedirectStandardOutput = $true
$StartInfo.RedirectStandardError = $true
$StartInfo.UseShellExecute = $false
$StartInfo.WorkingDirectory = "working directory path"
$process = [System.Diagnostics.Process]::Start($StartInfo)
# At this point can access process properties, e.g.:
Write-Host ("Started process with PID=" + $process.Id)
# Saving output to a file
$stderr = $process.StandardError
if ($stdout -ne $null) {
$output = $stdout.ReadToEnd()
$outfile = "location and name of file to save output to"
if ($output -ne "") { $output | Out-File $outfile }
}
# Saving standard error output to a file
$stdout = $process.StandardOutput
if ($stderr -ne $null) {
$errors = $stderr.ReadToEnd()
$errfile = "file to save errors to"
if ($errors -ne "") { $errors | Out-File $errfile }
}
[void] $process.WaitForExit
7. Get Script Own Path
(From: Get Script Directory)
$scriptPath = Split-Path $MyInvocation.MyCommand.Path
Syntax and Cmdlets
1. Show Something on Screen
Write-Host "whatever you want to show on screen"
2. Run WMI Query
gwmi win32_service # or other class
Also handy in conjunction with filter:
gwmi win32_service | where-object {$_.Name -eq "service name" }
… And query on top of that:
gwmi win32_service | where-object {$_.Name -eq "service name" } | select Status,State,StartName,StartMode
3. Text File
Reading:
Get-Content "my file"
Writing:
Set-Content "my file" "my content"
Appending:
Add-Content "my file" "my content"
4. Check if File Exists
test-path "file path and name"
5. String Functions
See: The String’s the Thing
6. Comparison Operators
See: About Comparison Operators
7. Special Characters (like tab, newline)
`0 -- Null
`a -- Alert
`b -- Backspace
`n -- New line
`r -- Carriage return
`t -- Horizontal tab
`' -- Single quote
`" -- Double quote
…
KSBYTES 