remove empty lines from text file with PowerShell

Question

I know that I can use:

gc c:\FileWithEmptyLines.txt | where {$_ -ne ""} > c:\FileWithNoEmptyLines.txt

to remove empty lines. But How I can remove them with '-replace' ?

Answer 1

I found a nice one liner here >> http://www.pixelchef.net/remove-empty-lines-file-powershell. Just tested it out with several blanks lines including newlines only as well as lines with just spaces, just tabs, and combinations.

(gc file.txt) | ? {$_.trim() -ne "" } | set-content file.txt

See the original for some notes about the code. Nice :)

Answer 2

This piece of code from Randy Skretka is working fine for me, but I had the problem, that I still had a newline at the end of the file.

(gc file.txt) | ? {$_.trim() -ne "" } | set-content file.txt

So I added finally this:

$content = [System.IO.File]::ReadAllText("file.txt")
$content = $content.Trim()
[System.IO.File]::WriteAllText("file.txt", $content)

Answer 3

You can use -match instead -eq if you also want to exclude files that only contain whitespace characters:

@(gc c:\FileWithEmptyLines.txt) -match '\S'  | out-file c:\FileWithNoEmptyLines

Answer 4

Not specifically using -replace, but you get the same effect parsing the content using -notmatch and regex.

(get-content 'c:\FileWithEmptyLines.txt') -notmatch '^\s*$' > c:\FileWithNoEmptyLines.txt

Answer 5

You can't do replacing, you have to replace SOMETHING with SOMETHING, and you neither have both.

Answer 6

(Get-Content c:\FileWithEmptyLines.txt) | 
    Foreach { $_ -Replace  "Old content", " New content" } | 
    Set-Content c:\FileWithEmptyLines.txt;

Answer 7

If you actually want to filter blank lines from a file then you may try this:

(gc $source_file).Trim() | ? {$_.Length -gt 0}

Answer 8

This will remove empty lines or lines with only whitespace characters (tabs/spaces).

[IO.File]::ReadAllText("FileWithEmptyLines.txt") -replace '\s+\r\n+', "`r`n" | Out-File "c:\FileWithNoEmptyLines.txt"

Answer 9

This removes trailing whitespace and blank lines from file.txt

PS C:\Users\> (gc file.txt) | Foreach {$_.TrimEnd()} | where {$_ -ne ""} | Set-Content file.txt

Answer 10

file

PS /home/edward/Desktop> Get-Content ./copy.txt

[Desktop Entry]

Name=calibre Exec=~/Apps/calibre/calibre

Icon=~/Apps/calibre/resources/content-server/calibre.png

Type=Application*

---

Start by get the content from file and trim the white spaces if any found in each line of the text document. That becomes the object passed to the where-object to go through the array looking at each member of the array with string length greater then 0. That object is passed to replace the content of the file you started with. It would probably be better to make a new file... Last thing to do is reads back the newly made file's content and see your awesomeness.

(Get-Content ./copy.txt).Trim() | Where-Object{$_.length -gt 0} | Set-Content ./copy.txt

Get-Content ./copy.txt