MS WINDOWS POWER SHELL

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MS WINDOWS POWER SHELL

• CSE 535 Operating Systems

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What is Power Shell

• PowerShell is Microsoft Windows
• object-oriented programming language
• interactive command line shell
• PowerShell designed to
• automate system tasks
• such as batch processing
• create systems management tools
• for commonly implemented processes

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What is it for?

• The PowerShell language is similar to Perl.
• PowerShell includes
• more than 130 standard command line tools
• for functions that formerly required users
• to create scripts in VB, VBScript or C.

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Where to Download?

• http//www.microsoft.com/downloads/details.aspx?Fa
  milyID50633a1f-a665-425d-923c-1a269f8ac084displa
  yLangen

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Windows PowerShell Cmdlet

• Cmdlet (or Command-let)
• which .NET objects can be accessed
• from the command line.
• A Cmdlet name consists of two elements
• a verb and a noun
• Example
• one of the most useful Cmdlets
• Get-help

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Automating Tasks

• PowerShell offers ways
• to automate tasks
• Cmdlets
• very small .NET classes
• appear as system commands
• Scripts
• combinations of cmdlets and associated logic.
• Executables
• standalone tools
• Instantiation of standard .NET classes.

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Integrating with .NET

• PowerShell
• integrates with the .NET environment
• Can be embedded within other applications.
• Over a hundred cmdlets are included
• to be used separately
• or combined with others
• to automate more complex tasks
• Users can
• also create and share cmdlets.

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Abbreviations for Cmdlets

• there are abbreviations
• for some of the Cmdlets, for example
• Get-Process
• Can also be typed as
• ps

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Linux-similar Cmdlets

• ps
• is command familiar to Linux users
• as the command
• to view details about currently running
  processes.
• there are a number of
• other Linux-PowerShell parallels
• man is the same as Get-Help detailed
• ls is the same as Get-ChildItem
• pwd is the same as Get-Location

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Understanding Aliases

• PowerShell commands are usually long.
• example Get-ChildItem.
• However, PowerShell has aliases.
• Example
• dir is the same as Get-ChildItem
• get-alias
• get-alias dir

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Obtaining PowerShell

• PowerShell is installed
• in Windows Server 2008
• is also part of Windows 7,
• it does not come ready loaded with XP or Vista!

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Running PowerShell

• Once PowerShell has been installed
• then it can be run in two ways
• Click on Start, Run
• and then type in powershell
• Start a new command prompt
• and then type in powershell
• the user can start using
• the PowerShell commands.

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Cmdl ps

• One very useful Cmdlet is ps
• or get-process
• lists the currently running processes
• the number of memory page (frame)s
• the percentage of processor usage

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Pipe and Sort

• The list is sorted alphabetically
• according to the process name.
• You can sort WS field
• According to the memory usage
• To do this the user
• pipes the output of ps
• to a second Cmdlet sort-object
• ps sort-object WS descending

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Sorting wrt Memory Usage
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Filtering Splitting the Commands

• User can filter that
• the powershell not to be seen in output
• Add a filter
• piped Cmdlets can be
• split over multiple lines
• ps where-object FilterScript
• _.processname -ne "powershell"
• sort-object WS descending

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Filtered
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To concatenation symbol

• The concatenation symbol (gt)
• will send the result output file
• after the information has been converted to HTML
• so that it can then be viewed in a web browser
• ps
• where-object -FilterScript
• _.processname -ne "powershell"
• sort-object WS descending
• convertto-html -property Name,
• WS gt ps.html

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Displaying in Browser
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Find all the processes on a computer that started
today

• Get-Process Where _.starttime -ge
  datetimetoday

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Find the processes that use more than 1000 MB of
memory and kill them

• get-process where-object _.WS -gt 1000MB
  stop-process -whatif

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Calculate the number of bytes in the files in a
directory

• get-childitem measure-object -property length
  -sum

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Defining Variables

• PS C\gt a 5
• PS C\gt a
• 5
• PS C\gt

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Determine Variable

• PS C\gt a.GetType()

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Piped Commands

• dir sort LastWriteTime more

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• PS C\WINDOWSgt a dir sort LastWriteTime
• PS C\WINDOWSgt a0
• PS C\WINDOWSgt a1