title: Trying to generate a temporary txt file and then delete it
body: <p>I have a site where I want a user to be able to download some data as a text file, without permanently saving the file on my server. The approach I'm trying is to  use JavaScript to send a POST,  using PHP to generate and save a text file. On   success, JavaScript will open that file in a separate window. After a few seconds delay, it will then send a POST with the file to delete.</p>
  
  <p>I have most of it working, but for some reason, when I try to delete the file, I keep getting an error - No such file or directory.  I don't know why,  especially since using a test file to delete in the same directory works fine. Here's what I'm using on the javascript side:</p>
  
  <pre><code>////CREATE FILE
      function exportGroup() {
  
  $.post("../Modules/Export_Mod/export_mod.php",
  { submit:'export',
    groupIndex: groupSelect.value,
    userRole: 'admin',
    serial: &lt;?php echo $serial;?&gt;
  },
  function(data,status){
  
  //open created file in new window  
  window.open("../Modules/Export_Mod/"+data);
  
  removeExport(data);
  });
  
  };
  
  
  
   //////REMOVE FILE   
      function removeExport(filename) {
  ///After 1 second, send post to delete file
  setTimeout(function() {
              $.post("../Modules/Export_Mod/export_mod.php",
              { submit:'removeExport',
                  file: filename
  
  
              },
              function(data,status){  
              data;
  
              });
   }, 1000);
  
  }
  </code></pre>
  
  <p>and my PHP:</p>
  
  <pre><code>//I'm creating the file successfully with this
  ...
  $filename = $groupName."_group_export.txt"; 
  $content = $header.$dataStr; 
  $strlength = strlen($content); 
  $create = fopen($filename, "w"); 
  $write = fwrite($create, $content, $strlength);
  $close = fclose($create); 
  </code></pre>
  
  <p>But when I try to delete a second (or more) later using this:</p>
  
  <pre><code>if (($_POST)&amp;&amp;($_POST['submit']=='removeExport')){
  
  $file = $_POST['file'];
  
  unlink($file);   ///works when using an already-existing file in the same directory ... unlink('test.txt');
  
  }
  </code></pre>
  
  <p>I get the error.    The first thing am wondering is if I'm approaching this the right way. If not, is there a better way to do it? And then the second thing I'm wondering is why I'm getting this error and what I need to change to make it work. </p>