Purpose : Reads the update steps from file "update" 
           Usage   : rdupdate [-f -i -inter -ver -h -?].
 Options : 
 -f FILE : the data is read from file FILE
           rather than from ./update
           The string FILE may be a relative or full path-name.
 -i DIR : data is stored in directory DIR
 -inter : enables interactive plotting
 -ver    : Version information about the program 
 -h      : Print this help text. 
 -?      : Print this help text.