Exchange cmdlet syntax

Exchange cmdlet reference articles use a standardized method that describes key aspects about the cmdlet. For example:

• Parameters that are available on the cmdlet.
• Values that each parameter accepts.
• Parameters that can be used together, and parameters that need to be used separately.

This article explains these conventions, and also the syntax that's required to run commands in Exchange PowerShell.

Command conventions in Exchange PowerShell

Exchange PowerShell help follows conventions that indicate what's required or optional, and how to enter parameters and values when you run a command. These command conventions are listed in the following table.

Symbol	Description
-	A hyphen indicates a parameter. For example, -Identity.
< >	Angle brackets indicate the possible values for a parameter. For example, -Location <ServerName> or -Enabled <$true | $false>.
[ ]	Square brackets indicate optional parameters and their values. For example, [-WhatIf] or [-ResultSize <Unlimited>]. Parameter-value pairs that aren't enclosed in square brackets are required. For example, -Password <SecureString>. Square brackets around the parameter name itself indicates a positional parameter (you can use the parameter value without specifying the parameter name), and positional parameters can be required or optional. For example, Get-Mailbox [[-Identity] <MailboxIdParameter>] means the Identity parameter is positional (because it's enclosed in square brackets) and optional (because the whole parameter-value pair is enclosed in square brackets), so you can use Get-Mailbox -Identity <MailboxIdParameter> or Get-Mailbox <MailboxIdParameter>. Similarly, Set-Mailbox [-Identity] <MailboxIdParameter> means the Identity parameter is positional (because it's enclosed in square brackets) and required (because the whole parameter-value pair isn't enclosed in square brackets), so you can use Set-Mailbox -Identity <MailboxIdParameter> or Set-Mailbox <MailboxIdParameter>.
|	Pipe symbols in parameter values indicate a choice between values. For example, -Enabled <$true | $false> indicates the Enabled parameter can have the value $true or $false.

These command conventions help you understand how a command is constructed. Except for the hyphen that indicates a parameter, you don't use these symbols as they're described in the table when you run cmdlets in Exchange PowerShell.

Parameter sets in Exchange PowerShell

Parameter sets are groups of parameters that can be used with each other in the same command. Each parameter set contains at least one parameter that isn't available in the other parameter sets, but parameter sets typically share some parameters.s.

Many cmdlets have only one parameter set, which means that all parameters can be used with each other. Other cmdlets have several parameter sets, which means some parameters can't be used with other parameters. For example, suppose the following parameter sets are available on the New-SystemMessage cmdlet:

New-SystemMessage -DsnCode <EnhancedStatusCode> -Internal <Boolean> -Language <CultureInfo> -Text <String> [-Confirm] [-DomainController <Fqdn>] [-WhatIf] <CommonParameters>

New-SystemMessage -QuotaMessageType <QuotaMessageType> -Language <CultureInfo> -Text <String> [-Confirm] [-DomainController <Fqdn>] [-WhatIf] <CommonParameters>

The following parameters are available in the first parameter set, so you can use them in the same command:

• DsnCode
• Internal
• Language
• Text
• Confirm
• DomainController
• WhatIf

The following parameters are available in the second parameter set, so you can use them in the same command:

• QuotaMessageType
• Language
• Text
• Confirm
• DomainController
• WhatIf

The parameters DsnCode and Internal are available only in the first parameter set. The parameter QuotaMessageType is available only in the second parameter set. So, you can't use the following parameters in the same command:

• DsnCode and QuotaMessageType.
• Internal and QuotaMessageType.

The following parameters are available in both parameter sets, so you can use them in any New-SystemMessage command:

• Language
• Text
• Confirm
• DomainController
• WhatIf

The <CommonParameters> entry indicates the cmdlet supports the basic Windows PowerShell parameters that are available on virtually any cmdlet (for example, Verbose). You can use common parameters with parameters from any parameter set. For more information, see about_CommonParameters.

Quotation marks in Exchange PowerShell

In Exchange PowerShell, you use single quotation marks ( ' ) or double quotation marks ( " ) to enclose parameter values that contain spaces. For example, the following commands behave the same:

• Get-ReceiveConnector -Identity "Contoso Receive Connector"

• Get-ReceiveConnector -Identity 'Contoso Receive Connector'

In the previous examples, if you don't enclose the value in single or double quotation marks, the command fails because PowerShell treats each word as a new argument (it thinks Contoso is the value of the Identity parameter, and Receive is the value of an unspecified positional parameter). In this example, the error looks like this:

A positional parameter cannot be found that accepts argument 'Receive'

For plain text values, single quotation marks vs. double quotation marks don't really matter. But, the choice is important when variables are involved:

• Double quotation marks: Variables are substituted with their actual values.
• Single quotation marks: Variables are treated literally.

For example, $Server = Mailbox01 results in the following output based on which quotation marks you use:

• "$Server Example" results in Mailbox01 Example.
• '$Server Example' results in $Server Example.

For more information about variables, see about_Variables and about_Automatic_Variables.

Escape characters in Exchange PowerShell

In any programming language, an escape character is used to identify special characters literally, and not by their normal function in that language. In Exchange PowerShell, when you enclose a text string in double quotation marks, the escape character is the back quotation mark escape character ( ` ).

For example, if you want the output The price is $23, enter the value "The price is `$23". The escape character is required on the dollar sign character ( $ ) because $ defines variables in PowerShell.

If you enclose the string in single quotation marks, the only special character you need to worry about is the single quotation mark character itself, which requires two single quotation marks to escape ( '' ).

For example, if you want the output Don't confuse two single quotation marks with a double quotation mark!, enter the value 'Don''t confuse two single quotation marks with a double quotation mark!'.

Command operators in Exchange PowerShell

The following table shows the valid operators that you can use in an Exchange command. Some of these symbols were also described in the earlier Command conventions in Exchange PowerShell section. However, these symbols have different meanings when they're used on the command line as operators. For example, the minus sign that's used to indicate a parameter can also be used in a command as a mathematical operator.

Operator	Description
=	The equal sign is an assignment character. The value on the right side of the equal sign is assigned to the variable on the left side of the equal sign (for example, $x= Get-Mailbox). You can also use other characters with the equal sign: +=: Add the value on the right side of the equal sign to the current value that's contained in the variable on the left side of the equal sign. -=: Subtract the value on the right side of the equal sign from the current value that's contained in the variable on the left side of the equal sign. *=: Multiply the current value of the variable on the left side of the equal sign by the value that's specified on the right side of the equal sign. /=: Divide the current value of the variable on the left side of the equal sign by the value that's specified on the right side of the equal sign. %=: Modify the current value of the variable on the left side of the equal sign by the value that's specified on the right side of the equal sign.
:	Use a colon to separate a parameter's name from the parameter's value. For example, -Enabled:$True. A colon separator works and is optional on virtually all parameter-value pairs. A colon separator is required on switch parameters. For more information about switch parameters, see about_Parameters.
!	The exclamation point is the logical NOT operator. The combined pair != means "not equal to."
[ ]	Brackets specify the index value of an array position. Index values are offsets that always start at zero. For example, in the array named $Red, the value of the tenth position in the array is $Red[9]. Brackets can also assign a type to a variable. For example, to identify the variable named $A as XML, use $A=[XML] "<Test><A>value</A></Test>". The following variable types are available: Array, Bool, Byte, Char, Char[], Decimal, Double, Float, Int, Int[], Long, Long[], RegEx, Single, ScriptBlock, String, Type, and XML.
{ }	Use braces to include an expression in a command. For example, Get-Process | Where {$_.HandleCount -gt 400}
|	Use the pipe symbol to pipe the output of one command to another command. For example, Get-Mailbox -Server SRV1 | Set-Mailbox -ProhibitSendQuota 2GB.
>	Use the right-angle bracket to send the output of a command to a file. If the file already exists, the contents are overwritten. For example, Get-TransportRule > "C:\My Documents\TransportRules.txt".
>>	Use double right-angle brackets to append the output of a command to an existing file. If the file doesn't exist, a new file is created. For example, Get-TransportRule >> "C:\My Documents\TransportRules.txt".
"	Use double quotation marks to enclose text strings that contain spaces. As previously described, variables are replaced with their actual values.
$	The dollar sign indicates a variable. For example, to create a variable named $Blue with the value 10, use $Blue = 10. After you store the variable, you can use it as the value of a parameter.
@	The at symbol references an associative array. For more information, see about_Arrays.
$( )	A dollar sign with parentheses indicates command substitution. You can use command substitution when you want to use the output of one command as an argument in another command. For example, Get-ChildItem $(Read-Host -Prompt "Enter FileName: ").
..	Double-periods indicate a value range. For example, if an array contains several indexes, you can return the values of all indexes between the second and fifth indexes by running the command: $Blue[2..5].
+	The plus sign operator adds two values together. For example, 6 + 6 equals 12.
-	The minus sign operator subtracts one value from another value (for example, 12 - 6 equals 6) or indicates a negative number (for example, -6 * 6 equals -36).
*	You can use an asterisk to: Match strings: For example, Get-User | Where-Object {$_.Department -like 'Sales*'}) Multiply numeric values: For example, 6 * 6 equals 36 Repeat the string value a specified number of times: For example, "Test" * 3 equals TestTestTest
/	A forward slash divides one value by another. For example, 6 / 6 equals 1.
%	The percent sign has the following uses: In a numerical evaluation, it returns the remainder from a division operator. For example, 6 % 4 equals 2. In a pipeline, it's shorthand for the ForEach-Object cmdlet. For example, Import-Csv C:\MyFile.csv | ForEach-Object {Set-Mailbox $_.Identity -Name $_.Name} is the same as Import-Csv C:\MyFile.csv | % {Set-Mailbox $_.Identity -Name $_.Name}.
?	The question mark character is shorthand for the Where-Object cmdlet. For example, Get-Alias | Where-Object {$_.Definition -eq "Clear-Host"} is the same as Get-Alias | ? {$_.Definition -eq "Clear-Host"}.