@{
 ViewData["Title"] = "Home Page";
 }

 <div class="text-center">
    <h1 class="display-4">Welcome</h1>
 <p>Please Upload An Excel File.</p>
<input type="file" name="datafile" style="margin-left: 10px; margin-top:
 15px; vertical-align: top; font-size:18px; background-color: white; margin-
 left:160px; margin-top:15px; width:250px; height:40px /">
 </div>
 <form method="get" asp-controller="Home" asp-action="Log">
<div class="form-group">
    <p>Read</p>
    <input type="button" value="Read" />
</div>

[HttpGet]
    public IActionResult Log()
    {
        var webRoot = _env.WebRootPath;
        var file = Path.Combine(webRoot, "Output,txt");
        //var lines = System.IO.File.ReadAllText()
        System.IO.File.ReadAllText(file);

        return Content(file);
    }