MicrosoftВ® Windows PowerShell(TM) Step By Step (Step By Step (Microsoft))

The Get-Member cmdlet retrieves information about the members of objects. Although this may not seem very exciting, remember that because everything returned from a cmdlet is an object, we can use the Get-Member cmdlet to examine the methods and properties of objects. When the Get-Member cmdlet is used with Get-ChildItem on the filesystem, it returns a listing of all the methods and properties available to work with the filesystem object.

One of the more interesting features of Windows PowerShell is that cmdlets return objects. An object is a thing that gives us the ability to either describe something or do something. If we are not going to describe or do something, then there is no reason to create the object. Depending on the circumstances, we may be more interested in the methods, or the properties. As an example, let’s consider rental cars. I travel a great deal in my role as a consultant at Microsoft, and I often need to obtain a rental car.

When I get to the airport, I go to the rental car counter, and I use the New-Object cmdlet to create the rentalCAR object. When I use this cmdlet, I am only interest in the methods available from the rentalCAR object. I will need to use the DriveDowntheRoad method, the StopAtaRedLight method, and perhaps the PlayNiceMusic method. I am not, however, interested in the properties of the rentalCAR object.

At home, I have a cute little sports car. It has exactly the same methods as the rentalCAR object, but I created the sportsCAR object primarily because of its properties. It is green and has alloy rims, a convertible top, and a 3.5-liter engine. Interestingly enough, it has exactly the same methods as the rentalCAR object. It also has the DriveDowntheRoad method, the StopAtaRedLight method, and the PlayNiceMusic method, but the deciding factor in creating the sportsCAR object was the properties, not the methods.

1. Start Windows PowerShell by using Start | Run | Windows PowerShell. The PowerShell prompt will open by default at the root of your Documents And Settings.

2. Use an alias to refer to the Get-Alias cmdlet. To find the correct alias, use the Get-Alias cmdlet as follows:

   get-alias g*

3. After you have retrieved the alias for the Get-Alias cmdlet, use it to find the alias for the Get-Member cmdlet. One way to do this is to use the following command, simply using gal in place of the Get-Alias name you used in the previous command:

   gal g*

4. The listing of aliases defined that begin with the letter g appears as a result of the previous command. The output is shown here:

   CommandType Name Definition ----------- ---- ---------- Alias gal Get-Alias Alias gc Get-Content Alias gci Get-ChildItem Alias gcm Get-Command Alias gdr Get-PSDrive Alias ghy Get-History Alias gi Get-Item Alias gl Get-Location Alias gm Get-Member Alias gp Get-ItemProperty Alias gps Get-Process Alias group Group-Object Alias gsv Get-Service Alias gsnp Get-PSSnapin Alias gu Get-Unique Alias gv Get-Variable Alias gwmi Get-WmiObject Alias gh Get-Help

5. Use the gal alias to obtain a listing of all aliases that begin with the letter g. Pipe the results to the Sort-Object cmdlet, and sort on the property attribute called definition. This is shown here:

   gal g* |sort-object -property definition

6. The listings of cmdlets that begin with the letter g are now sorted, and the results of the command are as follows:

   CommandType Name Definition ----------- ---- ---------- Alias gal Get-Alias Alias gci Get-ChildItem Alias gcm Get-Command Alias gc Get-Content Alias gh Get-Help Alias ghy Get-History Alias gi Get-Item Alias gp Get-ItemProperty Alias gl Get-Location Alias gm Get-Member Alias gps Get-Process Alias gdr Get-PSDrive Alias gsnp Get-PSSnapin Alias gsv Get-Service Alias gu Get-Unique Alias gv Get-Variable Alias gwmi Get-WmiObject Alias group Group-Object

7. Use the alias for the Get-ChildItem cmdlet and pipe the output to the alias for the Get-Member cmdlet. This is shown here:

   gci | gm

8. To only see properties available for the Get-ChildItem cmdlet, use the membertype argument and supply a value of property. Use Tab Completion this time, rather than the gci | gm alias. This is shown here:

   get-childitem | get-member -membertype property

9. The output from this command is shown here:

   TypeName: System.IO.DirectoryInfo 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;} Exists Property System.Boolean Exists {get;} Extension Property System.String Extension {get;} FullName Property System.String FullName {get;} 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;} Name Property System.String Name {get;} Parent Property System.IO.DirectoryInfo Parent {get;} Root Property System.IO.DirectoryInfo Root {get;} TypeName: System.IO.FileInfo 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;}

10. Use the membertype argument of the Get-Member cmdlet to view the methods available from the object returned by the Get-ChildItem cmdlet. To do this, supply a value of method to the membertype argument, as follows:

    get-childitem | get-member -membertype method

11. The output from the previous list returns all the methods defined for the Get-ChildItem cmdlet. This output is shown here:

    TypeName: System.IO.DirectoryInfo Name MemberType Definition ---- ---------- ---------- Create Method System.Void Create(), System.Void Creat... CreateObjRef Method System.Runtime.Remoting.ObjRef CreateOb... CreateSubdirectory Method System.IO.DirectoryInfo CreateSubdirect... Delete Method System.Void Delete(), System.Void Delet... Equals Method System.Boolean Equals(Object obj) GetAccessControl Method System.Security.AccessControl.Directory... GetDirectories Method System.IO.DirectoryInfo[] GetDirectorie... GetFiles Method System.IO.FileInfo[] GetFiles(String se... GetFileSystemInfos Method System.IO.FileSystemInfo[] GetFileSyste... GetHashCode Method System.Int32 GetHashCode() GetLifetimeService Method System.Object GetLifetimeService() GetObjectData Method System.Void GetObjectData(Serialization... GetType Method System.Type GetType() get_Attributes Method System.IO.FileAttributes get_Attributes() get_CreationTime Method System.DateTime get_CreationTime() get_CreationTimeUtc Method System.DateTime get_CreationTimeUtc() get_Exists Method System.Boolean get_Exists() get_Extension Method System.String get_Extension() get_FullName Method System.String get_FullName() get_LastAccessTime Method System.DateTime get_LastAccessTime() get_LastAccessTimeUtc Method System.DateTime get_LastAccessTimeUtc() get_LastWriteTime Method System.DateTime get_LastWriteTime() get_LastWriteTimeUtc Method System.DateTime get_LastWriteTimeUtc() get_Name Method System.String get_Name() get_Parent Method System.IO.DirectoryInfo get_Parent() get_Root Method System.IO.DirectoryInfo get_Root() InitializeLifetimeService Method System.Object InitializeLifetimeService() MoveTo Method System.Void MoveTo(String destDirName) Refresh Method System.Void Refresh() SetAccessControl Method System.Void SetAccessControl(DirectoryS... set_Attributes Method System.Void set_Attributes(FileAttribut... set_CreationTime Method System.Void set_CreationTime(DateTime v... set_CreationTimeUtc Method System.Void set_CreationTimeUtc(DateTim... set_LastAccessTime Method System.Void set_LastAccessTime(DateTime... set_LastAccessTimeUtc Method System.Void set_LastAccessTimeUtc(DateT... set_LastWriteTime Method System.Void set_LastWriteTime(DateTime ... set_LastWriteTimeUtc Method System.Void set_LastWriteTimeUtc(DateTi... ToString Method System.String ToString()

12. Use the up arrow key to retrieve the previous Get-ChildItem | Get-Member -MemberType method command, and change the value method to m* to use a wild card to retrieve the methods. The output will be exactly the same as the previous listing of members because the only membertype beginning with the letter m on the Get-ChildItem cmdlet is the MemberType method. The command is as follows:

    get-childitem | get-member -membertype m*

13. Use the -inputobject argument to the Get-Member cmdlet to retrieve member definitions of each property or method in the list. The command to do this is as follows:

    get-member -inputobject get-childitem

14. The output from the previous command is shown here:

    PS C:\> get-member -inputobject get-childitem TypeName: System.String Name MemberType Definition ---- ---------- ---------- Clone Method System.Object Clone() CompareTo Method System.Int32 CompareTo(Object value),... Contains Method System.Boolean Contains(String value) CopyTo Method System.Void CopyTo(Int32 sourceIndex,... EndsWith Method System.Boolean EndsWith(String value)... Equals Method System.Boolean Equals(Object obj), Sy... GetEnumerator Method System.CharEnumerator GetEnumerator() GetHashCode Method System.Int32 GetHashCode() GetType Method System.Type GetType() GetTypeCode Method System.TypeCode GetTypeCode() get_Chars Method System.Char get_Chars(Int32 index) get_Length Method System.Int32 get_Length() IndexOf Method System.Int32 IndexOf(Char value, Int3... IndexOfAny Method System.Int32 IndexOfAny(Char[] anyOf,... Insert Method System.String Insert(Int32 startIndex... IsNormalized Method System.Boolean IsNormalized(), System... LastIndexOf Method System.Int32 LastIndexOf(Char value, ... LastIndexOfAny Method System.Int32 LastIndexOfAny(Char[] an... Normalize Method System.String Normalize(), System.Str... PadLeft Method System.String PadLeft(Int32 totalWidt... PadRight Method System.String PadRight(Int32 totalWid... Remove Method System.String Remove(Int32 startIndex... Replace Method System.String Replace(Char oldChar, C... Split Method System.String[] Split(Params Char[] s... StartsWith Method System.Boolean StartsWith(String valu... Substring Method System.String Substring(Int32 startIn... ToCharArray Method System.Char[] ToCharArray(), System.C... ToLower Method System.String ToLower(), System.Strin... ToLowerInvariant Method System.String ToLowerInvariant() ToString Method System.String ToString(), System.Stri... ToUpper Method System.String ToUpper(), System.Strin... ToUpperInvariant Method System.String ToUpperInvariant() Trim Method System.String Trim(Params Char[] trim... TrimEnd Method System.String TrimEnd(Params Char[] t... TrimStart Method System.String TrimStart(Params Char[]... Chars ParameterizedProperty System.Char Chars(Int32 index) {get;} Length Property System.Int32 Length {get;}

15. This concludes the procedure for using the Get-Member cmdlet.

    Quick Check

    Q. To retrieve a listing of aliases beginning with the letter g that is sorted on the definition property, what command would you use?

    A. gal g* | sort-object -property definition