 history entries.  A history entry is
declared as follows:

<pre class="example">     typedef void *histdata_t;
     
     typedef struct _hist_entry {
       char *line;
       char *timestamp;
       histdata_t data;
     } HIST_ENTRY;
     </pre>

   <p>The history list itself might therefore be declared as

<pre class="example">     HIST_ENTRY **the_history_list;
     </pre>

   <p>The state of the History library is encapsulated into a single structure:

<pre class="example">     /*
      * A structure