What Is The Correct Absolute Path?

Our system writes a file to this location:
= = = = =

function ExportToCSV($records)

{

$filename = "C:\\inetpub\\vhosts\\julesthorntrust.com\\httpdocs\\grantapps\\docuploads\\application_form.csv";

= = = = =
What is the correct code to write this same file to the same directories on a linux server with cPanel???
This is the code that IS NOT working:
= = = = =

$filename = "\\home\\jttcom\\public_html\\grantapps\\docuploads\\application_form.csv";

= = = = =
User is "jttcom" and everything after \\public_html\\ is correct (except maybe the \\'s).