about_uid
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
"/[email protected]: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:
"/[email protected]:443/VirtualMachine=VirtualMachine-vm-88/CDDrive=3001/"
#Then $UidUtil.GetParentUid($uid) will return:
"/[email protected]:443/VirtualMachine=VirtualMachine-vm-88/"
Example 2: GetParentUid(string uid, string parentKey)
# If $uid is equal to:
"/[email protected]:443/VirtualMachine=VirtualMachine-vm-88/CDDrive=3001/"
# Then the call below
$UidUtil.GetParentUid($uid, "VirtualMachine")
#will return:
"/[email protected]:443/VirtualMachine=VirtualMachine-vm-88/"
#And
$UidUtil.GetParentUid($uid, "VIServer")
#will return:
"/[email protected]:443/"
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U.S. Patents listed at http://www.vmware.com/go/patents.
Copyright © VMware, Inc. All rights reserved.