boolean PEAR_PackageUpdate::savePreferences ( 
    string $pref_file
      = ''
    
   )
Saves the user's preferences to the preference file.
$pref_file
     The path to the file to save user's preferences to.
   throws PEAR_PACKAGEUPDATE_ERROR_PREFFILE_WRITEACCESS,
   when user's preference file has no WRITE access right.
  
   throws PEAR_PACKAGEUPDATE_ERROR_PREFFILE_WRITEERROR,
   when an I/O error occured while writing user's preference file contents.
  
since 0.4.0a1
This function can not be called statically.
boolean - TRUE if the user's preferences were saved successfully, FALSE othewise.