function hash_add(key, val, fname)% HASH_ADD Append key,value pair to end of hashtable stored in a file% function hash_add(key, val, filename)%% See hash_lookup for an exampleif ~exist(fname, 'file')  % new hashtable  hashtable.key{1} = key;  hashtable.value{1} = val;else  %hashtable = importdata(fname);  %hashtable = load(fname, '-mat');  load(fname, '-mat');  Nentries = length(hashtable.key);  hashtable.key{Nentries+1} = key;  hashtable.value{Nentries+1} = val;endsave(fname, 'hashtable', '-mat');