open FILE, "user/test" or die "Can't open file! Perl says '$!'";
  or 
open (FILE, "user/test") or die "Can't open file! Perl says '$!'";
  or
open (FILE, "user/test") || die "Can't open file! Perl says '$!'";

##</code><code>##

open FILE, "filename" || die $!;  #ERROR - DON'T USE THIS