PowerShell for Microsoft SharePoint 2010 : Comparison Operators

The -eq operator returns True or an array of matching values if it can match the value on the right with one or more values on the left. The operator returns True if an exact match is made.

PS > "http://SPServer01" -eq "http://SPServer01"
True
PS > "http://SPServer01" -eq "http://SPServer01/Site"
False

In the first example, we use the –eq operator to compare two identical strings. In the second example, we add a few lines to the value on the right. Since the strings are not identical, False is returned.

We can also use the –eq operator to match an argument on the right side with an array of values on the left.

PS > "http://SPServer01", "http://SPServer02" -eq "http://SPServer02"
http://SPServer02

The -ne operator returns True if the left value and the right value are not identical. If the left side of the operation contains multiple values, the operator returns ones that do not match the value on the right.

PS > "http://SPServer01" -ne "http://SPServer01"
False
PS > "http://SPServer01","http://SPServer02" -ne "http://SPServer01"
http://SPServer02

The -gt operator returns True if the left value is greater than the right value. The -ge operator returns True if the left value is greater than or equal to the right value.

PS > (Get-SPSiteAdministration -Identity http://SPServer01).UsersCount
9
PS > (Get-SPSiteAdministration -Identity http://SPServer01).UsersCount -ge 9
True
PS > (Get-SPSiteAdministration -Identity http://SPServer01).UsersCount -gt 9
False


					  

In this example, we use the Get-SPSiteAdministration cmdlet to retrieve the number of users of a site. In this case, there are nine users. We then use the –ge operator to check if the number of users is greater than or equal to nine, which returns True. Next, we check if the number of users is greater than nine, which returns False.

To see if the left value is less than the right value, use the -lt operator. The –le operator is for less-than or equal-to comparisons.

PS > (Get-SPSiteAdministration -Identity http://SPServer01).UsersCount -lt 9
False
PS > (Get-SPSiteAdministration -Identity http://SPServer01).UsersCount -le 9
True


					  

The –like and –notlike operators are similar to the –eq and –ne operators, but instead of matching exact values, they allow wildcards to be used.

PS > "http://SPServer01" -like "http://SPServer01"
True
PS > "http://SPServer01/Site" -like "http://SPServer01*"
True

In the first example, we use the –like operator to compare two identical strings. Since the strings match, True is returned. In the second example, we use a wildcard character when we compare the values. The wildcard character matches any given character. If the left side of the operation contains multiple values, the operator returns matching values, rather than True or False, as shown in the next example.

PS > "http://SPServer01/internal/site1",
>> "http://SPServer01/external/site1" -like "*external*"
>>
http://SPServer01/external/site1

For case-sensitive evaluation, use the –clike operator, as demonstrated here:

PS > "http://SPServer01" -clike "http://SPServer01"
True
PS > "http://SPServer01" -clike "http://SPSERVER01"
False

The following examples demonstrate how to use the –notlike operator.

PS > "http://SPServer01" -notlike "http://SPServer01"
False
PS > "http://SPServer01/Site" -notlike "http://SPServer01"
True
PS > "http://SPServer01/Site" -notlike "http://SPServer01*"
False

If the left side of the operation contains multiple values, the operation returns values that do not match, as shown here:

PS > "http://SPServer01/internal/site1",
>> "http://SPServer01/external/site1" -notlike "*external*"
>>
http://SPServer01/internal/site1

The –match and –notmatch operators try to match one or more of the set of string values on the left side of the operation using regular expressions. Regular expressions are a very powerful means of pattern matching (not specific to PowerShell or any other technology), which allow you to create very complex and effective comparisons. Here are some examples:

• Match http://SPServer01/Site with http://SPServer01:

  PS > "http://SPServer01/Site" -match "http://SPServer01"
  True
  

• Match http://SPServer01/Site with a regular expression that checks if the string starts with http://:

  PS > "http://SPServer01/Site" -match "^http://"
  True
  

• Check if http://SPServer01/Site starts with http://, followed by any number of alphanumeric characters, followed by /, followed by any number of alphanumeric characters and ends with an e:

  PS > "http://SPServer01/Site" -match "^http://\w*/\w*e$"
  True
  

As you can see, it is possible to build up complex match patterns using regular expressions. Similar to the –clike operator, -cmatch performs case-sensitive matching.

You can also use multiple values on the left side and match against a value on the right side, as shown in this example:

PS > "http://SPServer01/Site",
>> "http://SPServer01",
>> "http://SPServer02" -match "http://SPServer01"
>>
http://SPServer01/Site
http://SPServer01

This example returns the left values that match the right value.

The -replace operator in Windows PowerShell is used to find and replace substrings in a string value. It assumes its input is a regular expression. You can use the -replace operator to search for and replace a specific pattern.

PS > "http://SPServer01/Site" -replace "^http","https"
https://SPServer01/Site

Here, we replace http with https. We use the ^ character to match the beginning of the original string.

Here is an example that uses a more complex replacement pattern:

PS > "http://SPServer01/Site" -Replace "/{2}\w*/","//SPServer02/"
http://SPServer02/Site

This example compares the string "http://SPServer01/Site" to the specified pattern and replaces the part of the string that starts with two / characters, contains any number of alphanumeric characters, and ends with another /.