Support WSL without requiring `wslview` or `xdg-open`

[Seeker14491]

Currently on WSL we require either wslview or xdg-open to be available on the system, but there are WSL distros that don't include either preinstalled.

[bugadani]

Hi! Since this issue is about enhancing WSL support, I think this comment may be relevant here so I don't open a separate issue.

I just found your crate (I'm trying to open some generated stuff from WSL(2) and I've been reading a lot of cargo src to see how it opens docs) and it looks like open() has regressed in 0.6. With 0.5.2, I'm able to open a document in my browser, but the same code does not work on 0.6.

[Seeker14491]

What is your wslu version (run wslview --version)? I think there were some relevant bug fixes in v4.1.0.

[bugadani]

$> wslview --version
wslu v2.3.6; wslview v06

This is an Ubuntu 20.04 that hasn't been updated in ages, to be honest.

[Seeker14491]

Yeah, that version is 3+ years old. The current version works properly, though I would like to avoid regressions for people using older versions if possible.

[tgross35]

This doesn't seem like it would be too bad. The file is pretty simple, and wslview --verbose ... tells you exactly what it is doing. Link: https://github.com/wslutilities/wslu/blob/b6fa4b70b22909337cb13b5b2ea9845f733f60ff/src/wslview.sh

E.g. wslview --verbose http://google.com just calls powershell

/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe -NoProfile -NonInteractive $'\342\200\223ExecutionPolicy' Bypass -Command '[Console]::OutputEncoding = [System.Text.Encoding]::UTF8; [Console]::InputEncoding = [System.Text.Encoding]::GetEncoding(437); Start' '"http://google.com"'

And opening a file:

/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe -NoProfile -NonInteractive $'\342\200\223ExecutionPolicy' Bypass -Command '[Console]::OutputEncoding = [System.Text.Encoding]::UTF8; [Console]::InputEncoding = [System.Text.Encoding]::GetEncoding(437); Start' '"\\wsl$\Ubuntu"'

Opening a html file in browser just works

/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe -NoProfile -NonInteractive $'\342\200\223ExecutionPolicy' Bypass -Command '[Console]::OutputEncoding = [System.Text.Encoding]::UTF8; [Console]::InputEncoding = [System.Text.Encoding]::GetEncoding(437); Start' '"\\wsl$\Ubuntu\home\tmgross\foo\target\doc\foo\index.html"'