Introducing Microsoft PowerShell

5/9

Key concepts: PowerShell Pipeline and PowerShell Objects

Source:  Microsoft

PowerShell is an object-oriented language, which makes it different than other command shells even though it may look similar. For example, if you type dir you get a list of files in the current directory, similar but not identical to that in a standard Windows command shell. However in PowerShell, dir (as well as ls, for those familiar with Linux or UNIX) is an alias for get-childitem which returns a collection of objects. By default, the output from dir only shows four properties of each file object: Mode, LastWriteTime, Length and Name. What if you wanted to know the CreationTime? How do you even know that there is a CreationTime property?

You can explore PowerShell objects using a couple of key features. One is the PowerShell pipeline. The pipeline character is | and using this passes the output to the following cmdlet. The format-list cmdlet will show all the properties, when used with the * argument. So by typing:

dir | format-list *

you can see all the properties of each file object, including CreationTime. You could also use the Select-Object (or select) cmdlet to display the exact properties you want, or the Where-Object (or where) cmdlet to filter the output. So this would show files larger than 100MB in or below the current folder and save the results in a text file:

dir -r | where length -gt 100mb | select fullname,length  | out-file bigfiles.txt

View All Photo Stories

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

SearchCIO

SearchSecurity

SearchNetworking

SearchDataCenter

SearchDataManagement

Close