Description | 
  | 
This routine sets the default credentials cache name.  If
the default name is not passed in the argument name, it
defaults to the first valid entry of the following values: the KRB5CCNAME logical
name, the file krb5cc_<PID> in
a [.TMP] directory in the user’s
login directory (where <PID> is
the user’s process ID).  If the KRB5CCNAME logical
name is defined, it must not be a system-wide logical name.