@(#)README	1.2

This program creates and manages a linked list data structure.
It gives the user the following options:

1. To create and add the first node to a linked list.

2. To add a single node to the pre-existing linked list.
   The list must already exist before a new node can be added.
   The nodes should be maintained in ascending order based on
   the data value within the nodes by inserting new nodes into
   the proper place within the list. If the data value matches
   a data value already in the list, then the new node should be
   inserted after any previous nodes that contain the same data
   value. The program should reject new nodes with an ID field
   that matches a pre-existing node.

3. To delete a node from the linked list structure based on
   the ID field within the node.

4. To search the list and display all nodes found to contain
   an ID that matches the target search ID.

5. To display the nodes within the list from start to end by
   printing the ID and data fields of each.

6. To terminate the program by entering X as a command.

Attempts to create a list should be rejected if a list already
exits. Attempts to add to or access the list should be rejected
if the list does not already exist. The integer should be used
as an ID and the floating point value should be used as the data
value for the node. Allocate each node as a 3-word unit that
contains the ID, data value and a link to the node that follows.

+--------------+-------------------+---------------+
|   ID field   |   data field      |   link field  |
+--------------+-------------------+---------------+

Use the sbrk syscall to obtain memory for the nodes.

When adding a node to the list, the new node should be inserted
into the proper place within the list so as to keep the list in
ascending order based on the floating point data values within
the nodes.
The link field within each node contains the address of the
node that logically follows. A null link field contains 0 and
indicates the final node within the linked list structure.
A separate head pointer is used to specify the first node
within the list. A null head pointer denotes an empty list.
