Powershell

My latest hobby has been learning Powershell.

Powershell is the long-awaited Windows equivalent of the Unix shell.  It doesn’t have things like grep, awk, sed, ps, that would be way too sensible. It can however do everything a UNIX shell can and a whole lot more, as it plugs into all of Microsoft’s application APIs.

However, like the UNIX shell it comes with a steep learning curve, but once climbed, it’s an inseparable tool, leaving Cygwin struggling in the dust.

Some example queries:

Show me all xml files containing “con” in the title, and “connect” in the contents:

gci -include *con*.xml -recurse |select-string “connect”

Or even better: Show me all .xml and .ini files modified in the last 15 days, larger than 5 MB which contain “connect” or “open” in the contents

gci -recurse -include *.xml, *.ini | Where-object {$_.Length -gt 5000000} | Where-Object {$_.LastWriteTime -gt (get-date).AddDays(-15)}| select-String “connect|open”

Mark all .ini files as read-only:

get-childitem -force -recurse -include *.ini -erroraction continue $directoryLocation | foreach { $_.Set_IsReadOnly($true)}

Find all .xml files and replace all occurrences of Value=”.*” with Value=”YYY”

gci -include *.xml -recurse | foreach {gc $_ | foreach { [regex]::Replace($_, “(VALUE=\s*`”)(.*?)(`”.*$)”,’$1YYYY$3′) } set-content $_;}

List all duplicated files in a given directory:

$dupList=get-childitem -force -recurse -filter $fileType -erroraction continue $directory | Group-Object -Property name | ? { $_.count -gt 1 }

Start a service on a remote computer:

Get-WmiObject -computer akl-tfs01 Win32_Service -Filter “Name=’MichellesService’” | Start-Service

Restart a remote computer:

(gwmi win32_operatingsystem -ComputerName MyServer -cred(get-credential)).Win32Shutdown(6)

Connect to a database and execute a query:

$SqlConnString = “Server = $SqlServer; Database = $Database; user = $SqlUser; password = $SqlPass”

$SqlConnection = New-Object System.Data.SqlClient.SqlConnection

$SqlConnection.ConnectionString = $SqlConnString

$SqlCmd = New-Object System.Data.SqlClient.SqlCommand

$SqlCmd.CommandText = “Select * from mytable”

$SqlCmd.Connection = $SqlConnection

$SqlAdapter = New-Object System.Data.SqlClient.SqlDataAdapter

$SqlAdapter.SelectCommand = $SqlCmd

$DataSet = New-Object System.Data.DataSet

$a = $SqlAdapter.Fill($DataSet)

$SqlConnection.Close()

$DataSet.Tables | Select-Object -ExpandProperty Rows

Send an email (with attachment):

$SmtpClient = new-object system.net.mail.smtpClient

$SmtpClient.host = “localhost”

$msg = new-object System.Net.Mail.MailMessage $from, $to, $Title, $Body

$msg.IsBodyHTML=$true

$attachment = new-object System.Net.Mail.Attachment $file

$msg.Attachments.Add($attachment)

$SmtpClient.Send($msg)

$attachment.Dispose()

Powershell is available for download here.

(Alas learning Powershell comes at the cost of bash atrophy, so unable to provide the Linux equivalents.)