This document provides an overview of common string, data structure, file, operating system, security, XML, SQL, and web service operations in PowerShell. It discusses how to work with strings, arrays, dictionaries, hashtables, files, environment variables, events, services, WMI, encryption, XML processing, SQL queries and transactions, sending emails, downloading files from URLs, and using proxies. The document is a helpful reference for many PowerShell tasks.

1. EVERYTHING YOU
ALWAYS WANTED TO KNOW
ABOUT POWERSHELL *
©2016 LINKEDIN.COM/IN/GAETANOCAUSIO
* BUT WERE AFRAID TO ASK

2. WORKING WITH STRINGS

3. WORKING WITH STRINGS
# Some operations on strings
$line = "Hallo, this is a test string"
$line = $line.Replace("test", "123")
$idx = $line.IndexOf("this")
If ( [string]::Compare($stra, $strb, $True) ) { } # case sensitive compare
If ($line.StartsWith("Script")) { }
$line.Substring(2,3)
$line[2]
$line[2..4] # not a substring, this is an array !
$items = [Array]($line -split " ")
$lineArray = $line.ToCharArray()
"Hello $($MyName), today is $(get-date -format 'dd-MM')“ # string concatenation
# Formatting
"Today is {0:dddd}" -f (Get-Date) # Show day of the week
"{0:N2}" -f 1554.22272 # Two decimal positions
"{0:P}" -f (5/10) # Percentage
"{0:C}" -f 5 # Currency
"0x{0:x}" -f 55 # Convert to Hex

4. WORKING WITH STRINGS
# Be careful…
if ($abc -eq "") { Write-Host "is null" } # may not work as you expected!
if ([string]::IsNullOrEmpty($abc)) { Write-Host "is null" } # this is better...
-contains # is designed to work on arrays, not strings
-match # looks for a match inside a string and supports regexes
–like # looks for a match inside a string and supports wildcards
# Regular Expressions
If ("192.168.15.20" -match "d{1,3}.d{1,3}.d{1,3}.d{1,3}“) { }
If (([regex]::Matches($email, "[0-9]" )).count -gt 0) { }
$var = $var -replace '[{]?[0-9a-fA-F]{8}[-]?([0-9a-fA-F]{4}[-]?){3}[0-9a-fA-F]{12}[}]?', '[GUID]‘
$var = $var -replace '(19|20)dd(-)(0[1-9]|1[012])2(0[1-9]|[12][0-9]|3[01]) dd(:)dd(:)dd',
'[DATETIME]‘

5. DATA STRUCTURES

6. DATA STRUCTURES
# Array
[Array]$ErrorMessages = @("File does not exist.")
$ErrorMessages += "Unable to open file.“ # add item to an array
$ErrorMessages[1] = "Unable to open file for writing.“ # change item in an array
Write-Host $ErrorMessages[0] # access item from an array
# ! you cannot remove items from an array, use a .NET System.Collections.ArrayList instead
# reading items in an array:
foreach ($message in $ErrorMessages) { Write-Host $message }
$mixArray = @(12,"David",1.2,$(Get-Date))
$mixArray.length # items in de array
# Array of Array
[Array]$SkipFiles = @()
$SkipFiles +=, @("test.dat", 123)
$SkipFiles +=, @("file.dat", 7)
Write-Host $SkipFiles[1][0]

7. DATA STRUCTURES
# Dictionary
$dict = New-Object 'system.collections.generic.dictionary[string,int]'
$dict["David"] = 36
$dict["Joe"] = 27
# Hash Table
[hashtable]$ReturnData = @{}
$ReturnData.ErrorCode = 23
$ReturnData.ErrorMessage = "Failed to read database"
$ReturnData.ProcessedRecords = 0
$ReturnData.DataTable = new-object system.data.datatable
return $ReturnData

8. OPERATIONS ON FILES

9. OPERATIONS ON FILES
# Search or replace text in files
Get-ChildItem -Filter "*.xml" -Path "D:data" -Recurse | Select-String -pattern "123456“
(Get-Content "c:temptest.xml").replace('[ID]', '123456') | Set-Content "c:temptest.xml"
# Operations on file system
Copy-Item "d:datatest.log" "d:temp"
Move-Item -path "d:datatest.log" -destination "d:temp"
Rename-Item -path "d:datatest.xml" "test.xml.processed"
if ($(Test-Path "d:datalogs") -eq $false) {
New-Item -Name "logs" -Path "d:data" -ItemType directory
}
$data | Out-File -Append "d:datafile.dat“
# this will ask for confirmation, not handy in a script:
Remove-Item -Path "C:temp" -Filter "*.log" -Force
# this works better on a script:
Get-ChildItem -Path "C:temp" -Filter "*.log" | Remove-Item -force

10. OPERATIONS ON FILES
# Reading Files
[Array]$InRecords = Import-Csv -Path "d:test.csv" -Delimiter ',‘ -Header ID, Name, Age
$Data = Get-Content -Path $InputFile
[System.Object[]]$Triggers = Get-ChildItem -Filter "*.test.*.trg" -Path "d:data"
ForEach ($Trigger in $Triggers) {
$Trigger.BaseName
$Trigger.Name
$Trigger.FullName
}
# Handy
$HashCode = Get-FileHash -Path "$FileName" -Algorithm MD5
$HashCode.Hash

11. INTERACTIONS WITH OS

12. INTERACTIONS WITH OS
# Accessing environment variables
[Environment]::SetEnvironmentVariable("SYS_LOGS", "D:dataLogs", "Machine")
$logs = $([Environment]::GetEnvironmentVariable('SYS_LOGS','Machine'))
# Accessing Windows Events
if(![System.Diagnostics.EventLog]::SourceExists("CleanUp")) {
[System.Diagnostics.EventLog]::CreateEventSource("CleanUp",'Application')
}
Write-Eventlog -logname 'Application' -source "CleanUp" –eventID 17532 -EntryType Information
-message "your event message"
# Start a DOS batch command
Start-Process "D:batchrun.cmd" "-f -v" -Wait -WindowStyle Hidden-WorkingDirectory "D:batch"
# Start a PowerShell script from DOS
CALL %SystemRoot%system32WindowsPowerShellv1.0powershell.exe -NoLogo
-NonInteractive -File "D:scriptstest.ps1"

13. INTERACTIONS WITH OS
# Start - Stop Services
Disable-ScheduledTask -TaskName "Run Batch" -TaskPath "MyServices"
Stop-Service -DisplayName "MyWindowService"
iisreset /restart
Stop-Process -processname doc1gen* -Force
Restart-WebAppPool "MyWindowService“
# Get information from OS
Get-WmiObject -Query "SELECT TotalPhysicalMemory FROM Win32_ComputerSystem"
Get-WmiObject -Query "SELECT * FROM Win32_LogicalDisk" -ComputerName CLSERVER3
Get-WmiObject Win32_Processor -cn CLSERVER3
# list of all possible query options for above commands:
Get-WmiObject -List | Where-Object { $_.name -match 'memory' }

14. ABOUT SECURITY

15. ABOUT SECURITY
# Get user information
$userAccount = [System.Security.Principal.WindowsIdentity]::GetCurrent()
[System.Security.Principal.WindowsPrincipal]$userAccount).IsInRole("Administrator")
Get-ADUser -Filter { SAMAccountName -eq ‘USR01A' } -Properties extensionAttribute6
Get-ADUser -Filter { SAMAccountName -like 'usr*' } -Properties SamAccountName
# Encrypt a string (i.e. password)
ConvertTo-SecureString 'testtest' -AsPlainText -Force | ConvertFrom-SecureString | Out-File
-FilePath “c:temppassword.dat"
# Decrypt a string
$pswdSec = Get-Content "c:temppassword.dat" | ConvertTo-SecureString
$bPswd = [System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($pswdSec)
$pswd = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto($bPswd)

16. USING XML

17. USING XML
# Example of processing an XML file
[XML]$XML = Get-Content -Path "d:datafile.xml"
if ($XML.HasChildNodes) {
if ( $XML.'header'.'data'.HasChildNodes) {
foreach ($XMLData in $XML.'header'.'data') {
$XMLData.CustomerName
$XMLData.Children.Child[0].Name
$XMLData.InnerXml
if ($XMLData.SelectSingleNode("Age") -eq $null) {
# Node does not exist
[System.Xml.XmlElement]$Node = $XMLData.CreateElement("Age")
$Node.InnerText = "34"
$XMLData.AppendChild($Node) | Out-Null
} else {
# Update existing node
[System.Xml.XmlElement]$Node = $XMLData.SelectSingleNode("Age")
$Node.InnerText = "34"
}
}
$XMLData.Save("$OutputFile")
}
}

18. WORKING WITH SQL

19. WORKING WITH SQL
# Prepare SQL Connections
$SqlConnection = New-Object System.Data.SQLClient.SQLConnection
$SqlCommand = New-Object System.Data.SQLClient.SQLCommand
$SqlConnection.ConnectionString ="Server=MYSERVER;Database=TestDB;User
Id=SA_Account;Password=Passw0rd!;trusted_connection=False;"
$SqlCommand.Connection = $SqlConnection
# Fetch data via SQL query into a DataTable object
$SqlQuery = "SELECT BatchId, Status from [DataTable]“
$adapter = new-object system.data.sqlclient.sqldataadapter ($SqlQuery, $SqlConnection)
[system.data.datatable]$Batches = new-object system.data.datatable
$adapter.Fill($Batches) | out-null
foreach ($Row in $Batches)
{
"$($Row["BatchId"]) - $($Row["Status"])"
}

20. WORKING WITH SQL
# Execute an SQL statement
$SqlCommand.CommandText = "UPDATE [Table] SET Status=3 WHERE BatchId=$ID"
$SqlConnection.Open()
$result = $SqlCommand.ExecuteNonQuery()
$SqlConnection.Close()
# Working with Transactions
$SqlConnection.Open()
$SqlTransaction =
$SqlConnection.BeginTransaction([System.Data.IsolationLevel]::Serializable)
$SqlCommand.Transaction = $SqlTransaction
$result = $SqlCommand.ExecuteNonQuery()
if ($errors) {
$SqlTransaction.Rollback()
} else {
$SqlTransaction.Commit()
}
$SqlConnection.Close()

21. LAST BUT NOT LEAST

22. LAST BUT NOT LEAST
# Test for a valid email address
if ([bool]($record["EmailAdres"] -as [Net.Mail.MailAddress])) { }
# Report execution progress
Write-Progress -activity "Processing files" -status "Files read: " -PercentComplete 40
# Check speed of a command
Measure-Command -Expression { get-service | ForEach-Object { Write-Host $PSItem.Name -ForegroundColor
"green“ } }
# Ask for user input
$serverName = Read-Host "Enter server name:"
# It’s all about pipes:
function test {
begin { write-host "start" }
process { write-host "$_" }
end { write-host "end" }
}
"a", "b", "c" | test

23. BONUS WEBSERVICES

24. BONUS WEBSERVICES
# Send simple mail message
send-mailmessage -from "no-reply@company.com" -to david.john@domain.com
-subject "Test Email" -body "TEST" -smtpServer smtpmail.myserver.com
# Send HTML mail message with attachments
$smtpServer = "smtpmail.myserver.com"
$mailfrom = "no-reply@company.com"
$msg = new-object Net.Mail.MailMessage
$smtp = new-object Net.Mail.SmtpClient($smtpServer)
$msg.To.Add($MailAdres)
$msg.CC.Add($MailAdres)
$msg.From = $mailfrom
$msg.Bcc.Add("david.john@domain.com")
$msg.Subject = $MailSubject
$msg.Attachments.Add($attFile)
$msg.IsBodyHtml = $True
$msg.Body = $HTMLBody
$smtp.Send($msg)

25. BONUS WEBSERVICES
# Post URL http://service.com/send?op=set&form=report&id=1234
[hashtable]$postParams = @{}
$postParams.OP = 'set'
$postParams.FORM = 'report'
$postParams.ID = '1234'
$url = "http://service.com/send"
$rc = Invoke-WebRequest -Uri $url -Method GET -Body $postParams
# Download file from a URL web service
$webClient = New-Object System.Net.WebClient
$webClient.UseDefaultCredentials = $true
$url = "http://download.aspx?action=get&area=$($area)&id=$($id)"
$bron = $webClient.DownloadString($url)
# you may need to use a proxy for urls outside your network
If (Test-Connection "myserver.com" -Count 1 -Quiet ) {
$global:PSDefaultParameterValues = @{
'Invoke-RestMethod:Proxy'='http://myproxy.com/acc_base.pac'
'Invoke-WebRequest:Proxy'='http://myproxy.com/acc_base.pac'
'*:ProxyUseDefaultCredentials'=$true
}
}

26. BONUS WEBSERVICES
# SOAP request
$webService = "http://myserver/myservice/interfaceWcfService.svc"
$Action = "http://mycompany.com/interfaceWcfService/Contract/IinterfaceWcfService/Start"
[XML]$SOAPRequest = '<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/
envelope/" xmlns:con="http://mycompany.com/interfaceWcfService/Contract"><soapenv:Header/
><soapenv:Body><con:StartID><con:appName>APP_ID</con:appName></con:StartID></soapenv:Body></
soapenv:Envelope>‘
$soapWebRequest = [System.Net.WebRequest]::Create( $webService)
$soapWebRequest.Headers.Add( "SOAPAction", $Action)
$soapWebRequest.ContentType = "text/xml;charset=`"utf-8`""
$soapWebRequest.Accept = "application/xop+xml, application/dime, multipart/related, text/xml";
$soapWebRequest.Method = "POST"
$requestStream = $soapWebRequest.GetRequestStream()
$SOAPRequest.Save($requestStream)
$requestStream.Close()
# perform SOAP request
$resp = $soapWebRequest.GetResponse()
$responseStream = $resp.GetResponseStream()
# get response
$soapReader = [System.IO.StreamReader]($responseStream)
$ReturnXml = $soapReader.ReadToEnd()
$responseStream.Close()
"Webservice Response = $($resp.StatusDescription)"

27. THE END
©2016 LINKEDIN.COM/IN/GAETANOCAUSIO