How do I make a script cross compatible?

Detect the platform and offer two code blocks, one for Windows, one for Linux. Like this:

if uname &>/dev/null; then
    # Linux code here
else
    # Windows code here
fi

This is just an example picked at random, there are any number of ways to detect the platform.

an if statement using uname or some environmental $VARIABLE?

I use MSYS2 for a bash shell in Windows, so my example may not work depending on how you're executing the script on a Windows platform...but:

if command -v "cmd.exe" >/dev/null; then
    # Windows command
else
    # xdg-open
fi

You could also use type if command is not available.

I'd likely set a variable in the script, something like:

winhost="$(command -v "cmd.exe")"

Then, if sections of the script where I need to run different commands for each host type, you could use

if [ -n "${winhost}" ]; then
    # Windows command
else
    # xdg-open
fi

or

if [ -z "${winhost}" ]; then
    # xdg-open
else
    # Windows command
fi

As I do not have WSL1/2 set up on this machine, I'm unsure if this will work in that environment. You'll need to do some testing.

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