ConvertFrom-String

Syntax

ConvertFrom-String
                [-Delimiter <String>]
                [-PropertyNames <String[]>]
                [-InputObject] <String>
                [<CommonParameters>]

ConvertFrom-String
                [-TemplateFile <String[]>]
                [-TemplateContent <String[]>]
                [-IncludeExtent]
                [-UpdateTemplate]
                [-InputObject] <String>
                [<CommonParameters>]

Description

The ConvertFrom-String cmdlet extracts and parses structured properties from string content. This cmdlet generates an object by parsing text from a traditional text stream. For each string in the pipeline, the cmdlet splits the input by either a delimiter or a parse expression, and then assigns property names to each of the resulting split elements. You can provide these property names; if you do not, they are automatically generated for you.

The cmdlet's default parameter set, ByDelimiter, splits exactly on the regular expression delimiter. It does not perform quote matching or delimiter escaping as the Import-Csv cmdlet does.

The cmdlet's alternate parameter set, TemplateParsing, generates elements from the groups that are captured by a regular expression.

This cmdlet supports two modes: basic delimited parsing, and automatically-generated, example-driven parsing.

Delimited parsing, by default, splits the input at white space, and assigns property names to the resulting groups. You can customize the delimiter by piping the ConvertFrom-String results into one of the Format-* cmdlets, or you can use the Delimiter parameter.

The cmdlet also supports automatically-generated, example-driven parsing based on the FlashExtract, research work by Microsoft Research.

Examples

Example 1: Generate an object with default property names

PS C:\> "Hello World" | ConvertFrom-String

P1    P2
--    --
Hello World


PS C:\>

This command generates an object with default property names, P1 and P2. The results are P1="Hello" and P2="World".

Example 1A: Get to know the generated object

PS C:\> "Hello World" | ConvertFrom-String | Get-Member


   TypeName: System.Management.Automation.PSCustomObject

Name        MemberType   Definition
----        ----------   ----------
Equals      Method       bool Equals(System.Object obj)
GetHashCode Method       int GetHashCode()
GetType     Method       type GetType()
ToString    Method       string ToString()
P1          NoteProperty string P1=Hello
P2          NoteProperty string P2=World


PS C:\>

The command generates one object with properties P1, P2; both properties are of 'string' type, by default.

Example 2: Generate an object with default property names using a delimiter

PS C:\> "Hello World" | ConvertFrom-String -Delimiter "ll"

P1 P2
-- --
He o World


PS C:\>

This command generates an object with P1="He" and P2="o World" properties, by specifying the 'll' in Hello as the delimiter.

Example 3: Generate an object that contains two named properties

PS C:\> "Hello World" | ConvertFrom-String -PropertyNames FirstWord, SecondWord

FirstWord SecondWord
--------- ----------
Hello     World


PS C:\>

This command generates an object that contains two properties:

• FirstWord, with value "Hello"
• SecondWord, with value "World"

Example 4: Use an expression as the value of the TemplateContent parameter, save the results in a variable.

$template = @'
{Name*:Phoebe Cat}, {phone:425-123-6789}, {age:6}
{Name*:Lucky Shot}, {phone:(206) 987-4321}, {age:12}
'@

$testText = @'
Phoebe Cat, 425-123-6789, 6
Lucky Shot, (206) 987-4321, 12
Elephant Wise, 425-888-7766, 87
Wild Shrimp, (111)  222-3333, 1
'@

$testText  |
    ConvertFrom-String -TemplateContent $template -OutVariable PersonalData |
    Out-Null

Write-output ("Pet items found: " + ($PersonalData.Count))
$PersonalData


Pet items found: 4

Name          phone           age
----          -----           ---
Phoebe Cat    425-123-6789    6
Lucky Shot    (206) 987-4321  12
Elephant Wise 425-888-7766    87
Wild Shrimp   (111)  222-3333 1

C:\ >

This command uses an expression as the value of the TemplateContent parameter. The expression is saved in a variable for simplicity. Windows PowerShell understands now that the string that is used on the pipeline to ConvertFrom-String has three properties:

• Name
• phone
• age

Each line in the input is evaluated by the sample matches; if the line matches the examples given in the pattern, values are extracted and passed to the output variable defined.

The sample data, $template, provides two different phone formats:

• 425-123-6789
• (206) 987-4321

And, two different age formats:

• 6
• 12

This implies that phones like (206) 987 4321 will not be recognized, because there's no sample data that matches that pattern (there's no hyphen between the three digit sequence and the four digit sequence). Similar with 3 or more digit ages, they will not be recognized.

Example 5: Specifying data types to the generated properties

$template = @'
{[string]Name*:Phoebe Cat}, {[string]phone:425-123-6789}, {[int]age:6}
{[string]Name*:Lucky Shot}, {[string]phone:(206) 987-4321}, {[int]age:12}
'@

$testText = @'
Phoebe Cat, 425-123-6789, 6
Lucky Shot, (206) 987-4321, 12
Elephant Wise, 425-888-7766, 87
Wild Shrimp, (111)  222-3333, 1
'@

$testText  |
    ConvertFrom-String -TemplateContent $template -OutVariable PersonalData | Out-Null

Write-output ("Pet items found: " + ($PersonalData.Count))
$PersonalData


Pet items found: 4

Name          phone           age
----          -----           ---
Phoebe Cat    425-123-6789      6
Lucky Shot    (206) 987-4321   12
Elephant Wise 425-888-7766     87
Wild Shrimp   (111)  222-3333   1



C:\ >

This is the same example as No. 4, above; the only differences are in the pattern string that includes a data type for each desired property. Notice the difference in alignment for the age column between both examples.

Example 5A: Get to know the generated object

$template = @'
 {[string]Name*:Phoebe Cat}, {[string]phone:425-123-6789}, {[int]age:6}
 {[string]Name*:Lucky Shot}, {[string]phone:(206) 987-4321}, {[int]age:12}
 '@

 $testText = @'
 Phoebe Cat, 425-123-6789, 6
 Lucky Shot, (206) 987-4321, 12
 Elephant Wise, 425-888-7766, 87
 Wild Shrimp, (111)  222-3333, 1
 '@

 $testText  |
     ConvertFrom-String -TemplateContent $template -OutVariable PersonalData |
     Out-Null

 $PersonalData | Get-Member



   TypeName: System.Management.Automation.PSCustomObject

Name        MemberType   Definition
----        ----------   ----------
Equals      Method       bool Equals(System.Object obj)
GetHashCode Method       int GetHashCode()
GetType     Method       type GetType()
ToString    Method       string ToString()
age         NoteProperty int age=6
Name        NoteProperty string Name=Phoebe Cat
phone       NoteProperty string phone=425-123-6789

C:\ >

Get-Member shows age is of integer type.

Parameters

-Delimiter

-IncludeExtent

-InputObject

-PropertyNames

-TemplateContent

-TemplateFile

-UpdateTemplate

Inputs

String

Related Links

• ConvertFrom-String: Example-based text parsing
• ConvertFrom-StringData
• ConvertFrom-Csv
• ConvertTo-Xml