Function builtin_shell_exec 

fn builtin_shell_exec(
    args: &[RValue],
    _named: &[(String, RValue)],
) -> Result<RValue, RError>

Open a file or URL with the system’s default application.

Uses open on macOS, xdg-open on Linux, and cmd /c start on Windows. This is an interactive utility — it launches an external process and returns immediately without waiting for it to finish.

@param file character scalar: the file path or URL to open @return NULL (invisibly)