How can I replace newlines using powershell?

Question

Given test.txt containing:

test
message

I want to end up with:

testing
a message

I think the following should work but it doesn't:

Get-Content test.txt |% {$_-replace "t`r`n", "ting`r`na "}

How can I do a find and replace where what I'm finding contains CRLF?

Answer 1

A CRLF is two characters, of course, the CR and the LF. However, `n consists of both. For example:

PS C:\> $x = "Hello
>> World"

PS C:\> $x
Hello
World
PS C:\> $x.contains("`n")
True
PS C:\> $x.contains("`r")
False
PS C:\> $x.replace("o`nW","o There`nThe W")
Hello There
The World
PS C:\>

I think you're running into problems with the r. I was able to remove the r from your example, use only `n, and it worked. Of course, I don't know exactly how you generated the original string so I don't know what's in there.

(Edited - sorry about the formatting)

Answer 2

In my understanding, Get-Content eliminates ALL newlines/carriage returns when it rolls your text file through the pipeline. To do multiline regexes, you have to re-combine your string array into one giant string. I do something like:

$text = [string]::Join("`n", (Get-Content test.txt))
[regex]::Replace($text, "t`n", "ting`na ", "Singleline")

Clarification: small files only folks! Please don't try this on your 40GB log file :)