How to Select-String multiline?

Question

I am trying to Select-String on a text that is on multiple lines.

Example:

 "This is line1
 <Test>Testing Line 2</Test>
 <Test>Testing Line 3</Test>"

I want to be able to select all 3 lines in Select-String. However, it is only selecting the first line when I do Select-String -Pattern "Line1". How can I extract all 3 lines together?

Select-String -Pattern "Line1"

Answer 1

Select-String operates on its input objects individually, and if you either pass a file path directly to it (via -Path or -LiteralPath) or you pipe output from Get-Content, matching is performed on each line.

Therefore, pass your input as a single, multiline string, which, if it comes from a file, is most easily achieved with Get-Content -Raw (PSv3+):

Get-Content -Raw file.txt | Select-String -Pattern Line1

Note that this means that if the pattern matches, the file's entire content is output, accessible via the output object's .Line property.

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By contrast, if you want to retain per-line matching but also capture a fixed number of surrounding lines, use the -Context parameter.

Get-Content file.txt | Select-String -Pattern Line1 -Context 0, 2

Ansgar Wiechers' helpful answer shows how to extract all the lines from the result.