Using "open" command in WSL

I switched jobs a couple of months ago, and earlier this month, I got issued a MacBook for a work computer. I have long been a Windows user who never really used a Mac before—either for personal use or for work. So it has been a few interesting weeks since then, adjusting for the new operating system and everything it entails.

I remember hearing and reading about how macOS offers a great developer experience. Well, I have to admit that it’s been a pleasure to use the new MacBook although mostly thanks to this MacBook being a simply superior machine that costs many times more than my old HP. In terms of the development workflow and environment, WSL 2 already offers everything I can ask for including full Docker Docker support. In fact, my productivity on MacBook still suffers from switching between different keyboard shortcuts. 😭

One small thing I find quite useful in macOS, apart from its rich set of trackpad gestures, is the open command. It’s a simple built-in terminal command whose primary job is to open a file or a folder at a given path.¹ Although using terminal is mostly sufficient for navigating directories and manipulating files, sometimes it is helpful—even necessary—to leverage the convenience of GUI.² And running open . provides a great way to quickly switch from command line to GUI without having to clicking through folders in Finder to get to where I am in terminal.

Since I still need my good old Windows laptop for hobby projects and other personal stuff, I wondered: Can I have open in WSL?

After some research, I found that while there is no built-in open in Linux, Windows makes Explorer.exe available in command line. It does what is expected: Open Windows File Explorer at a given path. Although Explorer.exe comes with a different set of options,³ it is adequate for my intended use case. Even better, WSL has access to Windows PATH variable out of the box, thus making Explorer.exe available on its terminal.

So now I have Explorer.exe . to get mostly the same thing in WSL. But can I do better? Can I use it by typing open as in macOS?

My first naive approach to achieve this was to aliasing Explorer.exe to open, i.e. alias open="Explorer.exe". At first, it seemed to work just as intended: open . would open a File Explorer GUI window at the current location. Unfortunately, this quickly broke down when I tried to use it with slightly more complicated paths. For instance, open ./foo/bar would open File Explorer at Documents (i.e. the default path) instead of the path I provided. After a bit of experimentation, I learned that this was because Windows uses backslashes(\) for paths instead of forward slashes(/) like everybody else. And using Explorer.exe in WSL doesn’t change that, meaning I should type open .\\foo\\bar to get what I want. Not cool.

After some more experimentation, however, I learned that a simple shell script could solve this. The following is a couple of lines I added to ~/.bashrc:

function open() {
  Explorer.exe ${1//\//\\}
}
export -f open

This version of open takes an argument, applies a simple regex to it to replace forward slashes to backslashes, and uses the result as the argument for Explorer.exe. Then the line 4 exports the function open using the -f option. Since this code is part of .bashrc, open is made available as soon as I launch bash terminal. And this open can open any file or folder at any existing path on File Explorer—or even a URL on the default browser!

Of course, under the hood, it’s still good old Explorer.exe, so I cannot replicate the full functionality of the macOS open with all its options—at least not with a few lines of shell script. Nonetheless, for basic use cases, it is just as good as the original open. For that, I’m satisfied. 😎

Update (Dec 13, 2020): One of the readers of this post recently pointed me to wslpath, a simple utility tool that ships with WSL to “convert paths between Windows and Linux.” Using this, I can replace my regex solution with Explorer.exe "$(wslpath -w $1)". Thank you, Ted!

See this SS64.com page for more details on open. ↩
For example, drag-and-drop to upload files to web apps. ↩
See this SS64.com page for more details on Explorer.exe. ↩

Footnotes