Working with Cmdlets: Step-by-Step Exercises | MicrosoftВ® Windows PowerShell(TM) Step By Step (Step By Step (Microsoft))

In this exercise, we explore the use of the Get-ChildItem and Get-Member cmdlets in Windows PowerShell. You will see that it is easy to use these cmdlets to automate routine administrative tasks. We also continue to experiment with the pipelining feature of Windows PowerShell.

Start Windows PowerShell by using Start | Run | Windows PowerShell. The PowerShell prompt will open by default at the root of your Documents And Settings.
Use the Get-Alias cmdlet to retrieve a listing of all the aliases defined on the computer. Pipe this output to a Where-Object cmdlet. Specify a match argument against the definition property that matches the name of the Get-ChildItem cmdlet. The code is as follows:
```
 gal | where-object {$_.definition -match "get-childitem"}
```

The results from the previous command show three aliases defined for the Get-ChildItem cmdlet, as shown here:

 CommandType     Name                            Definition ----------- ----                   ---------- Alias           gci                             Get-ChildItem Alias           ls                              Get-ChildItem Alias           dir                             Get-ChildItem

Using the gci alias for the Get-ChildItem cmdlet, obtain a listing of files and folders contained in the root directory. This is shown here:
```
 gci
```
To identify large files more quickly, pipe the output to a Where-Object cmdlet, and specify the gt argument with a value of 1,000 to evaluate the length property. This is shown here:
```
 gci | where-object {$_.length -gt 1000}
```
To remove the cluttered data from your Windows PowerShell window, use cls to clear the screen. This is shown here:
```
 cls
```
Use the Get-Alias cmdlet to resolve the cmdlet to which the cls alias points. You can use the gal alias to avoid typing get-alias if you wish. This is shown here:
```
 gal cls
```
Use the Get-Alias cmdlet to resolve the cmdlet to which the mred alias points. This is shown here:
```
 gal mred
```
It is likely that no mred alias is defined on your machine. In this case, you will see the following error message:
```
 Get-Alias : Cannot find alias because alias 'mred' does not exist. At line:1 char:4 + gal <<<< mred
```
Use the Clear-Host cmdlet to clear the screen. This is shown here:
```
 clear-host
```
Use the Get-Member cmdlet to retrieve a list of properties and methods from the Get-ChildItem cmdlet. This is shown here:
```
 get-childitem | get-member -membertype property
```

The output from the above command is shown here. Examine the output, and identify a property that could be used with a Where-Object cmdlet to find the date that files have been modified.

 Name              MemberType Definition ----              ---------- ---------- Attributes        Property   System.IO.FileAttributes Attributes {get;set;} CreationTime      Property   System.DateTime CreationTime {get;set;} CreationTimeUtc   Property   System.DateTime CreationTimeUtc {get;set;} Directory         Property   System.IO.DirectoryInfo Directory {get;} DirectoryName     Property   System.String DirectoryName {get;} Exists            Property   System.Boolean Exists {get;} Extension         Property   System.String Extension {get;} FullName          Property   System.String FullName {get;} IsReadOnly        Property   System.Boolean IsReadOnly {get;set;} LastAccessTime    Property   System.DateTime LastAccessTime {get;set;} LastAccessTimeUtc Property   System.DateTime LastAccessTimeUtc {get;set;} LastWriteTime     Property   System.DateTime LastWriteTime {get;set;} LastWriteTimeUtc  Property   System.DateTime LastWriteTimeUtc {get;set;} Length            Property   System.Int64 Length {get;} Name              Property   System.String Name {get;}

Use the Where-Object cmdlet and choose the LastWriteTime property. This is shown here:
```
 get-childitem | where-object {$_.LastWriteTime}
```
Use the up arrow and bring the previous command back up onto the command line. Now specify the gt argument and choose a recent date from your previous list of files, so you can ensure the query will return a result. My command looks like the following:
```
 get-childitem | where-object {$_.LastWriteTime -gt "12/25/2006"}
```
Use the up arrow and retrieve the last command. Now direct the Get-ChildItem cmdlet to a specific folder on your hard drive, such as C:\fso, which may have been created in the step-by-step exercise from Chapter 1. You can, of course, use any folder that exists on your machine. This command will look like the following:
```
 get-childitem "C:\fso"| where-object {$_.LastWriteTime -gt "12/25/2006"}
```
Once again, use the up arrow and retrieve the last command. Add the recurse argument to the Get-ChildItem cmdlet. If your previous folder was not nested, then you may want to change to a different folder. You can, of course, use your Windows folder, which is rather deeply nested. I used my VBScript workshop folder, and the command is shown here (keep in mind that this command has wrapped and should be interpreted as a single line):
```
 get-childitem -recurse "d:\vbsworkshop"| where-object {$_.LastWriteTime -gt "12/25/2006" }
```
This concludes this step-by-step exercise. Completed commands for this exercise are in the StepByStep.txt file.