Single space between letters of Win32 executable output in PowerShell

Question

my $PSVersion output is as follows:

Name                           Value
----                           -----
PSVersion                      7.0.1
PSEdition                      Core
GitCommitId                    7.0.1
OS                             Microsoft Windows 10.0.19041
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

If I run

wsl -l

my output appears in the console as:

Windows Subsystem for Linux Distributions:
Ubuntu-20.04 (Default)
ubuntu-20.04-systemd

If I run

wsl -l | Out-File foo.txt

it appears in the file as:

W i n d o w s   S u b s y s t e m   f o r   L i n u x   D i s t r i b u t i o n s : 
 
 
 U b u n t u - 2 0 . 0 4   ( D e f a u l t ) 
 
 
 u b u n t u - 2 0 . 0 4 - s y s t e m d 
 

I've tried specifying different output encodings to Out-File to no avail. I'd like to understand what's going on and how to get around it.

Thank you!

Answer 1

wsl -l unexpectedly uses the UTF-16LE ("Unicode") character encoding for its output , resulting in extra NUL bytes ( 0x0 ) getting inserted between ASCII-range characters (which can appear like spaces) when PowerShell interprets the output (which it invariably does if you capture or redirect the output; display in the console is not affected), based on the encoding stored in [Console]::OutputEncoding , which defaults to the system's active OEM code page.

The solution is to (temporarily) set [Console]::OutputEncoding to match wsl 's output encoding :

$orig = [Console]::OutputEncoding
[Console]::OutputEncoding = [System.Text.Encoding]::Unicode # UTF-16LE

wsl -l > foo.txt # > is effectively like Out-File

[Console]::OutputEncoding = $orig

See this answer for custom function Debug-String , which facilitates diagnosing such encoding problems.