Description
For this project, write a C program that will implement a food ordering system used in a fast
food restaurant. This restaurant only serves burgers and salads and when people want to order
food, they give their name and food choices to the cashier and then wait until those in front of
them have been served. The program must use a linked list to implement the queue-like data
structure.
The linked list is to maintain the following information for each group that is waiting:
• name (we assume a maximum name length of 30 characters)
• food items (number of burgers and salads ordered)
• in-restaurant status: whether the group has called ahead or is waiting in the restaurant
The system allows you to call and put your order in before you arrive at the restaurant, but it
does not take orders for a specific time and date (i.e. 4 burgers and 2 salads for 7pm on
Saturday). Note: these call-ahead groups will still need to check in when they arrive, so the
cashier knows they are waiting in the restaurant.
Groups are added to the order list when they call-ahead or when they arrive at the restaurant.
Groups are always added to the end of the order list. The system will require that each name
used be unique. So when a group is added to the order list, the system must make sure that no
other group is already using that name.
The restaurant staff working in the kitchen have a steady speed in preparing food and they work
on one order at a time. On average, preparing a salad takes 5 minutes while burger takes 10
minutes.
The system needs to track how many food items have been ordered and provide customers with
an estimated wait time.
You can assume that every time an order is being called, it will go to the first group in line.
However, in order to pick up the food, the group needs to be present at the restaurant. If they are
not, then the system will call the next eligible group for pick up (an eligible group is a group that
the number of burgers and salads they ordered is less than or equal to prepared order).
The commands used by this system are listed below and are to come from standard input. Your
program is to prompt the user for input and display error messages for unknown commands or
improperly formatted commands. Note that the name of the group when given will be given as
the last item on the input line. The name of the group may contain white space characters in the
middle of the name but not at the beginning or end of the name. Each command given must
display some information about the command being performed. Code to implement this
interface is provided in the program proj4base.c.
CS 211 – Programming Practicum Spring 2019
Command Description
q Quit the program.
? List the commands used by this program and a brief description of how
to use each one.
a <#burgers>
<#salads>
Add the order to the order list using the given order and name
specifying the group is waiting in the restaurant. The order’s
information is added to the end of the list. If the name already exists in
the order list, give an error message and do not add the information.
c <#burgers>
<#salads>
Add the order to the order list using the given order and name
specifying the order as a call ahead order. The order’s information is
added to the end of the list. If the name already exists in the order list,
give an error message and do not add the information.
w
restaurant. If the name does not exist is the order list or is not a call
ahead group, give an error message.
r <#burgers>
<#salads>
Retrieve and remove the first order on the order list that is waiting in
the restaurant and contains less than or equal to number of prepared
burgers and salads. Note that “first” is the order that has been in the
order list the longest.
l
specified by the given name. If the name does not exist, give an error
message.
t
preparing burgers will take 10 minutes and preparing salads takes 5.
If the name does not exist, give an error message.
d Display the total number of orders in the order list. Also display the
names, order details and in-restaurant status of all orders in the order
list in order from first to last.
Note that <#burgers> and <#salads> are to be integer values and
The < and > symbols are NOT part of the input but being used to describe the input.
Use of C struct and C functions
When writing your code, you MUST create a C struct for the nodes in the linked list of the order
list. These data items must include the following (and may include others if desired):
• the name of the order
• the integer variables specifying details of the order (number of burgers and salads)
• the in-restaurant status (you should use an enum!)
• a pointer to the next node in the list
The pointer for the head of the linked list MUST be declared as a local variable in main() or
some other function. It may NOT be global. If you wish to have the head of the list enclosed in
a structure with some other information, that is OK (but certainly not required). The variable
used to access this structure; however, may not be global. Each operation performed on the
linked list MUST be done in its own function. These functions must take the head of the linked
list as the FIRST parameter.
CS 211 – Programming Practicum Spring 2019
Linked List Operations/Functions
You must write C functions for the following 8 operations. These functions must be called when
the specified commands are given as input.
addToList ( ) – This operation is to add a new node to the end of the linked list. This is to be
used when the a and c commands are given as input.
doesNameExist ( ) – This operation is to return a Boolean value indicating whether a name
already exists in the linked list. This is to be used when the a, c, w, t and l commands are given
as input.
updateStatus ( ) – This operation is to change the in-restaurant status when a call-ahead order
arrives at the restaurant. This operation will return a FALSE value if that order is already
marked as being in the restaurant. This is to be used when the w command is given as input.
retrieveAndRemove ( ) – This operation is to find the first in-restaurant order that matches the
order prepared for pick up at the counter. This operation is to return the name of group. This
group is to be removed from the linked list. This is to be used when the r command is given as
input.
countOrdersAhead ( ) – This operation is to return the number of orders waiting ahead of an
order with a specific name. This is to be used when the l command is given as input.
displayWaitingTime( ) – This operation is to return the estimated waiting time for the specific
name. The function will check the number of burgers and salads ordered ahead of the specified
name and using known preparing time (10 minutes for burger and 5 minutes for salad) calculates
the estimated wait time. This is to be used when t command is given as input.
displayOrdersAhead ( ) – This operation traverses down the list until a specific order name is
encountered. As each node is traversed, print out that node’s orders. This command is to be
used when the l command is given.
displayListInformation ( ) – This operation to traverse down the entire list from beginning to
end. As each node is traversed, print out that node’s name, order details and in-restaurant status.
This command is to be used when the d command is given as input.
Note that there may be a many-to-many relationship between the commands in the user interface
and the required functions. For example, the l command (“list”) relies on the following
functions: doesNameExist(), countOrdersAhead() and displayOrdersAhead().
Command Line Argument: Debug Mode
Your program is to be able to take one optional command line argument, the -d flag. When this
flag is given, your program is to run in “debug” mode. When in this mode, your program is to
display each order’s information as you traverse through the linked list of the order list. Note
that for the w, r, t and l commands, the entire list may not be traversed, so you only display the
part of the list that is needed to be traversed to complete the command.
CS 211 – Programming Practicum Spring 2019
When the flag is not given, this debugging information should not be displayed. One simple way
to set up a “debugging” mode is to use a boolean variable which is set to true when debugging
mode is turned on but false otherwise. This variable may be a global variable. Then using a
simple if statement controls whether information should be output or not.
if ( debugMode == TRUE )
printf (” Debugging Information \n”);
Provided Code for the User Inteface
The code given in proj4base.c should properly provide for the user interface for this program
including all command error checking. This program has no code for the linked list. It is your
job to write the functions for the specified operations and make the appropriate calls. Most of
the changes to the existing proj4base.c program need to be made in each of the doXXXX ( )
functions. Look for the comments of:
// add code to perform this operation here
Note: the head of the linked list is required to be a local variable in main and you are required to
pass the head of the linked to the operation functions. All of the doXXXX ( ) functions currently
have no parameters. It will then be expected that you will modify the function signatures of the
doXXXX() functions to allow for this information to be passed as required.
MULTIPLE SOURCE CODE FILES
Your program is to be written using at least three source code files. It must also have a makefile
and a header file to help with the compilation of the program. All of the storage structure code
(the linked list code) is to be in one source code file. The code in proj4base.c is to be separated
into two different source code files.
The following functions from proj4base.c are to be in one source code file (these are the user
interface functions):
• main()
• clearToEoln()
• getNextNWSChar()
• getPosInt()
• getName()
• printCommands()
The following functions from proj4base.c are to be in another source code file (these are the
functions that interact with the linked list functions):
• doAdd()
• doCallAhead()
• doWaiting()
• doRetrieve()
• doList()
• doDisplay()
• doEstimateTime()
CS 211 – Programming Practicum Spring 2019
The third source code file is to have the code that you are writing that will perform the linked list
implementation: The functions in this source code file will include the following functions plus
any other you write to handle the linked list:
• addToList()
• doesNameExist()
• updateStatus()
• retrieveAndRemove()
• countOrdersAhead()
• displayOrdersAhead()
• displayListInformation()
• displayWaitingTime()
If you add additional functions to your program, you can add those to whichever source code file
seems appropriate for that function (or create a fourth source code file or even a fifth).
You must also create a header file. The job of the header file is to contain the information so the
source code files can talk to each other. The header file (.h file) should contain the function
prototypes and any struct and/or typedef statements. Please review the .h file in the example
below.
The makefile MUST separately compile each source code file into a “.o” file and separately link
the “.o” files together into an executable file. Review the makefile in the example below to see
how this is done. The command to create the .o file is:
gcc –c program1.c
The command to link the files program1.o, program2.o and program3.o into an executable file is:
gcc program1.o program2.o program3.o
The above command will just name the executable file using the default name of a.out, most
often the –o option is given to provide a specific name for the executable file.
gcc program1.o program2.o program3.o –o program.exe
Example of Multiple Source Code Files
Consider the program contained in the following files:
• max1.c
• max2.c
• max.h
• makefile
This example shows how to set up this simplest of multiple source code file program. Note that
max1.c and max2.c just contain functions and a #include of max.h. The file max.h contains the
prototypes (or forward declarations) for all of the functions that are called from outside its source
code file and any “globally” needed information.
The makefile is a special file that helps in the compilation of the source code into the object files
into the executable file. A makefile is executed by the use of the make command. The syntax of
a makefile can be strange. The makefile will contain multiple rules. Each rule has the following
syntax:
target: dependencyList
commandLine
CS 211 – Programming Practicum Spring 2019
The multiple rules in the make file are separated by a blank line. Also note (this is VERY
IMPORTANT) the commandLine must use a TAB for its indentation! An example of a rule is:
max1.o: max1.c max.h
gcc -c max1.c
The commandLine is gcc -c max1.c, which will compile the source code file of max1.c into the
object code file of max1.o.
The target in the above example is the file max1.o, which is also the name of the file created
when the commandLine is executed. This relationship is what causes makefiles to work.
The dependencyList in the above example is the two files: max1.c and max.h, which are the
files needed for the commandLine to properly run. Again, this relationship is what causes
makefiles to work.
The make command uses the timestamps of the files in the target and the dependencyList. If any
file in the dependencyList has a more recent timestamp than the target file, the commandLine is
executed. The idea is that if the user has recently changed either max1.c or max.h, then the
object file max1.o needs to be re-compiled. Make is designed to help the programmer keep track
of what needs to be compiled next.
Make and makefile tutorials can be found at:
• http://mrbook.org/tutorials/make/
• http://www.gnu.org/software/make/manual/make.html
• http://www.opussoftware.com/tutorial/TutMakefile.htm
Coding Style
Don’t forget to use good coding style when writing your program. Good coding style makes
your program easier to be read by other people as the compiler ignores these parts/differences in
your code. Elements of good code style include (but may not be limited to):
• Meaningful variable names
• Use of functions/methods
• Proper indentation
• Use of blank lines between code sections
• In-line comments
• Function/method header comments
• File header comments
The Code Review Checklist also hints at other elements of good coding style.
CS 211 – Programming Practicum Spring 2019
Program Submission
You must zip all of your files needed for the program together and then submit the zip file for
this lab via the Assignments Page in Blackboard.
To help the TA, create a directory with your net-id and the assignment name, such as:
• netidProject4
Then put the 3 source code files, your header file and your makefile into this directory. Zip this
directory and submit the zip file.
