about_uid.help.txt

TOPIC
    about_uid
 
SHORT DESCRIPTION
    You can uniquely identify a PowerCLI object on a server or across multiple
    servers by specifying its Uid.
 
LONG DESCRIPTION
    A Uid is a string that consists of one or more key-value pairs separated by
    a slash ("/"). The key and the value within a pair are separated by an equal
    sign ("="). For example, the Uid if a virtual CD Drive might be
    "/VIServer=powershell@vc41-ga.pc:443/VirtualMachine=VirtualMachine-vm-88/CDDrive=3001/".
    To retrieve the Uid of an object, use its Uid property. For example:
 
    $vm = Get-VM -Name aaa
    $vm.Uid
 
    To ease work with Uids, there is a global Powershell variable $UidUtil that
    provides methods for processing Uids. Although the name of an object is
    unique within a server, PowerCLI allows you to run cmdlets on multiple
    servers and this can lead to ambiguity. This means that the name or the
    short ID you have provided to a cmdlet might correspond to multiple objects
    on different servers. To avoid this, you can identify a PowerCLI object on a
    server or across multiple servers by specifying its Uid (unique identifier).
    The Uid contains information about the target server. A Uid is a string that
    consists of one or more key-value pairs separated by a slash ("/"). The key
    and the value within a pair are separated by an equal sign ("="). The first
    key-value pair represents the server connection. The objects which have no
    server-side analog and only live in the local memory start with "/Local=/".
    A Uid is said to be parent of another Uid if it can be obtained from the
    child Uid by removing one or more key-value pairs from the end of the child
    Uid.
 
Processing UIDs
    The global variable $UidUtil provides the following methods for processing UIds:
    bool IsUid(string str) - Checks if the specified string is a valid Uid.
    string Append(string uid, string key, string value) - Appends the
    specified key and value to the specified Uid to form a child Uid. Any
    special characters will be encoded (in the same way as EncodeValue method).
    string GetKey(string uid) - Retrieves the key of the rightmost Uid element.
    string GetValue(string uid) - Retrieves the value of the rightmost Uid element.
    string GetValue(string uid, string key) - Retrieves the value of the
    leftmost Uid element which has the specified key. If the key is not present,
    returns $null.
    string EncodeValue(string plainString) - Encodes a string so that it can
    be used as a value of a Uid element (escapes delimiters).
    string DecodeValue(string encodedString) - Reverses the effect of Encode.
    string GetParentUid(string uid) - Returns the parent Uid of 'uid'.
    string GetParentUid(string uid, string parentKey) - Returns the shortest
    parent Uid of 'uid' which has a rightmost Uid element with the specified
    key. If the key is not present, returns $null.
    string GetConnectionUid(string uid) - Gets the Uid which represents the
    connection for this object. The connection Uid element is the first Uid element.
    bool IsOnConnection(string uid, string connectionKey, string
    connectionValue) - Reports whether uid belongs to the specified connection.
    void GetHelp() - Displays an about_ article with help information about the
    Uid concept and description of the methods functionality.
    The $UidUtil Powershell variable also exposes the following properties:
    string ElementDelimiter - The delimiter used to separate the different
    elements of a Uid.
    string KeyValueDelimiter - The delimiter used to separate the key and the
    value of a Uid element.
 
EXAMPLES
Example 1: GetParentUid(string uid)
    #if $uid is equal to:
    "/VIServer=powershell@vc41-ga.pc:443/VirtualMachine=VirtualMachine-vm-88/CDDrive=3001/"
     
    #Then $UidUtil.GetParentUid($uid) will return:
    "/VIServer=powershell@vc41-ga.pc:443/VirtualMachine=VirtualMachine-vm-88/"
 
Example 2: GetParentUid(string uid, string parentKey)
    # If $uid is equal to:
    "/VIServer=powershell@vc41-ga.pc:443/VirtualMachine=VirtualMachine-vm-88/CDDrive=3001/"
     
    # Then the call below
    $UidUtil.GetParentUid($uid, "VirtualMachine")
    #will return:
    "/VIServer=powershell@vc41-ga.pc:443/VirtualMachine=VirtualMachine-vm-88/"
     
    #And
    $UidUtil.GetParentUid($uid, "VIServer")
    #will return:
    "/VIServer=powershell@vc41-ga.pc:443/"
 
COPYRIGHT
    Copyright (C) VMware, Inc. All rights reserved. Protected by one or more
    U.S. Patents listed at http://www.vmware.com/go/patents.