ruby - Reading user-specific environment variables in Chef -

I'm new to Chef and Ruby and trying to understand how I can read an environment variable from a specific Linux / Windows user. And use it to keep a file.

What do I have to do, update our Oracle tnsnames.ora files for customer and DB installations.

These files can be in a code such as C: \ oracle or C: \ program files \ oracle> Windows or / u01 App / Oracle / Product / 11.2 / Network / Admin or /u01/app/oracle/producdt/10.2/network/admin in Linux / 100% I can not believe that I did not read any prescription in the dough and using it would know the exact location.

I can not find out if it is the type of syntax, whether I use it or not.

I doubt

  template "# {Dir.home ( "Oracle")} / network / admin / tnsnames.ora "source" tnsnames.ora.erb "[...] end   
 Do you want to do almost this only if it works only When there is no difference in the operating system except the location of the home directory.