COMP 2401 Intro. to Systems Programming - Assignment #3: Phone Simulation and Phone Network
COMP2401 - Assignment #3
In this assignment, you will gain experience in using structs and pointers. Make sure to put comments
in your code ... especially ones to describe your functions, definitions and important parts of your code.
You must also write your code as cleanly & efficiently as possible.
Assume that a private cell phone company wanted you to write a program to keep track of various calls made between its customers. You will use various structures to represent the type of phone plan, the customer, the calls made and the phone network itself. A header file called phoneNetwork.h has been provided with the necessary struct definitions that you will need as shown below ... with type name definitions shown in red:
// Structure that stores a phone plan that a customer has
typedef struct {
unsigned short int minutesAllowed; // # mins/month allowed in phone plan
unsigned short int minutesUsed; // # mins used this month so far
} PlanType;
// Structure that stores a customer
typedef struct { char
*name; id;
*number;
plan;
numOutCalls;
numInCalls;
// name of customer
// customer ID
// phone number of customer
// phone plan of customer
// number of calls made this month
// number of calls received this month
unsigned int char PlanType unsigned unsigned
} CustomerType;
short
short
// Structure that stores a phone call that was made
typedef struct { CustomerType CustomerType time_t
time_t } CallType;
madeFrom;
madeTo;
startTime;
endTime;
// customer who made call
// customer who was called
// time that call was started
// time that call ended
phone network’s customer and call data
CustomerType customers[MAX_CUSTOMERS]; // data for customers registered with network
// Structure that stores the
typedef struct {
unsigned int
CallType
unsigned int
numCustomers;
calls[MAX_CALLS];
numCalls;
// number of customers registered
// data for all calls that took place this month
// number of calls that took place this month
} PhoneNetworkType;
The next page shows an example of a phone network with 3 customers in which 2 phone calls were made. Make sure that you understand how the image matches up with the structures in the header file before you continue the assignment.
Download the phoneSimulation.c file. It contains a main() function with comments that indicate the steps you should follow. It also contains sample names, numbers and phone plan values that you will use. You will be writing a bunch of functions and procedures.
You must create a file called phoneNetwork.c that will contain ALL the functions and procedures that you will be asked to write.DO NOT write them in the phoneSimulation.c file.
You will need to include that additional file at the end of your gcc shell command so that it gets compiled along with the phoneSimulation.c file.
(1) Write a registerCustomer() procedure that will register a customer in the phone network defined by the phoneNetwork variable that is provided. The procedure must have the following signature which takes a pointer to a phone network, a name, a phone number and a number of allowed phone plan minutes/month:
registerCustomer(PhoneNetworkType *, char *, char *, int)
For each customer you should have some kind of global counter so that each time you register a
customer they get assigned a unique id (starting with 100001). It must return 1 if the customer was
able to be added (i.e., not past capacity) and 0 otherwise.
Call this procedure from the main() function so that it creates exactly 20 customers ... with the
names, phone numbers and the allowed number of phone plan minutes provided in the Sample
arrays.
(2) Write a displayCharges() procedure that takes a pointer to a PhoneNetworkType and then displays all customers in the phone network provided ... showing their id, phone number, name and phone plan minutes allowed. It should show “UN” for unlimited-minute phone plans and “PPM” for phone plans that require paying per minute of usage. Call this procedure at the end of the main() function as shown by the comment in the code. You will add more functionality to this procedure later. Make sure to test your code ... the output should be aligned nicely and approximately as follows:
ID Phone Number Name Plan -------------------------------------------------
100001 (613)111-1111
100002 (819)222-2222
100003 (613)333-3333
100004 (343)444-4444
100005 (819)555-5555
100006 (613)666-6666
100007 (343)777-7777
100008 (613)888-8888
Adam Bomm UN
Hugo First UN
Dan Druff 200
Mabel Syrup UN
Mike Rohsopht UN
Adam Sapple 100
Moe Skeeto 200
Anita Bath UN
Rusty Chain PPM
Stu Pitt 200
Val Crow UN
Neil Down UN
-
(3) Write a resetMonth() procedure that simulates the resetting of phone call data for a new month of calls. It must take a pointer to a PhoneNetworkType. The procedure should reset everything as if there have been no calls made in the network so that things begin from scratch. Call this procedure in your main() function right after creating the customers.
-
(4) Write a recordCall() function that simulates a call that has been made in the network. It must have the following signature, taking a pointer to the network as its 1st parameter:
char recordCall(PhoneNetworkType *, char *, char *, time_t, time_t);
The 2nd parameter is the phone number that the call was made from, the 3rd parameter is the phone number that the call was made to, the 4th parameter is the time that the call was started and the last parameter is the time that the call ended. The time is designed as a time_t type. This is a large integer number that represents the number of seconds that has elapsed since 00:00:00 UTC, January 1, 1970. It is the typical standard that is used to record time-of-day in computer science.
The function should return 0 if the call could not be recorded (this could happen if the number of calls that were made in the phone network has reached its capacity or if either of the phone numbers are invalid). Otherwise, the function should return 1. To record the call, you will need to do a few things. You will need to:
(a) Determine how many minutes the call lasted (rounded up to the nearest minute)
(b) Find the customer that made the call and record that number of minutes used as well as the fact that this customer made this outgoing phone call.
(c) Find the customer that received the call and record the fact that this customer received this incoming phone call. If it was a PAY_PER_MINUTE customer that received the call, the number of minutes used should be increased as a result of this phone call, but other types of phone plans do not need to have the minutes increased for incoming calls.
(d) Update the appropriate from/to/start/end information in the network’s calls array accordingly.
(5) To test the recordCall() function, after resetting the month in the main() function, you should write code to make 10 calls (we will increase this to 100 later). To do this, choose a random customer to make the call and a random one to receive the call (make sure that it is not the same customer that makes and receives the call at the same time as this is invalid). You will need to choose a random start time for the call and a random end time. To do this, we will need to generate realistic time_t values. There is a struct tm structure defined in <time.h> that allows us to specify an exact year, month, day, hour, minute and second time. Here is what the structure looks like:
struct tm { int tm_sec; int tm_min; int tm_hour; int tm_mday; int tm_mon; int tm_year; int tm_wday; int tm_yday; int tm_isdst;
};
// seconds 0-59
// minutes 0-59
// hours 0-23
// day of the month 1-31
// month 0-11
// year since 1900
// day of the week 0-6
// day in the year 0-365
// daylight saving time (we will use -1 to disable)
You should generate a start time for the phone call by making a variable of type struct tm and then setting its values so that the call was made in Feb 2024. The day of the month should be chosen randomly as a number from 1-29 (since 2024 is a leap year). The hour, minute and second of the day should all be chosen randomly.
To get your struct tm variable into a time_t format that you need for the recordCall() function, you simply call the mktime() function from <time.h> with the address of your struct tm variable. That function will return the value you need for your call’s start time. As for the call’s end time, you can take that start time value and simply add a random number of seconds so that the call lasts at most two hours (i.e., at most 120 mins * 60 seconds). At this point, you will not know if your code works properly until you write the next procedure.
(6) Write a displayCallLog() procedure that displays the phone call data. It must take a pointer to a PhoneNetworkType. For each call made, the procedure should display the phone number that the call was made from, the number it was made to, the start date/time of the call, the end date/time of the call and the length of time (in minutes with one decimal place) that the call lasted. The output should be formatted neatly and look roughly as follows:
Call From # Call To # Start Time: End Time Call Length -----------------------------------------------------------------------------------------
(613)555-1234
(613)999-1234
(613)444-1234
(613)555-1234
(613)555-1234
(343)888-5678
(343)777-7777
(343)777-7777
2024-02-28 13:33:57
2024-02-12 18:23:27
2024-02-06 12:49:37
2024-02-07 13:19:32
2024-02-25 07:26:46
2024-02-15 09:59:54
2024-02-16 09:52:32
2024-02-16 03:24:41
2024-02-12 20:35:15
2024-02-21 03:40:39
2024-02-28 14:51:59
2024-02-12 18:54:04
2024-02-06 12:50:00
21.7 minutes
112.7 minutes
99.5 minutes
40.2 minutes
11.7 minutes
100.1 minutes
76.8 minutes
78.0 minutes
30.6 minutes
0.4 minutes
Note: To extract the date/time information from the time_t values, you will need to get the time_t value into a struct tm variable so that you can extract what you need. To convert a time_t value called timeValue into a struct tm variable called daytime, you can call the localtime() function as follows: struct tm daytime = *localtime(&timeValue);
Don’t forget to adjust the year and month values accordingly after the conversion.
(7) Finally, we will adjust the displayCharges() procedure so that it computes and displays the appropriate monthly charges for each customer. Here is how the charges work:
(a) For customers with UNLIMTED minute phone plans, the base cost is $34.99 per month (before taxes).
(b) For customers with phone plans that have a specified number of minutes, the base cost is $9.99 per month. But there is an extra 15 cents charge for every minute that the customer went over the plan's allowed minutes. So, a customer that used up 126 minutes on a 100- minute phone plan would pay $9.99 + ($0.15 * 26) = $13.89 before taxes.
(c) For customers with a PAY_PER_MINUTE phone plan, the customer simply pays $0.15 per minute for the first 100 minutes and then they pay $0.35 for every minute over the 100.
Adjust your displayCharges() procedure so that it also displays (alongside the current customer information) the number of outgoing calls made, the number of incoming calls received, the number of minutes used, the number of minutes gone over, the base cost, the extra cos (for going over), the HST amount and the final total. The information must be aligned and displayed neatly. Here is an example of the output:
Phone Number Name Plan Out In Used Over Base Extra HST Total ----------------------------------------------------------------------------------------------------------------
(613)111-1111
(819)222-2222
(613)333-3333
(343)444-4444
(819)555-5555
(613)666-6666
(343)777-7777
(613)888-8888
(819)999-9999
(613)555-1234
(613)555-5678
(613)666-1234
(613)666-5678
(343)777-1234
(613)777-5678
(819)888-1234
(343)888-5678
(613)999-1234
(613)999-5678
(613)444-1234
Rob Banks
285 85
209 0
488 0
34.99 0.00 4.55
9.99 15.45 3.31
15.00 162.05 23.02
34.99 0.00 4.55
15.00 93.45 14.10
34.99 0.00 4.55
9.99 6.90 2.20
34.99 0.00 4.55
34.99 0.00 4.55
34.99 0.00 4.55
9.99 0.00 1.30
34.99 0.00 4.55
34.99 0.00 4.55
9.99 34.05 5.73
9.99 21.15 4.05
34.99 0.00 4.55
15.00 229.95 31.84
9.99 12.75 2.96
34.99 0.00 4.55
Sandy Beach UN
Adam Bomm UN 4 3
Hugo First UN
Dan Druff 200 4 6
Mabel Syrup UN
Mike Rohsopht UN
Adam Sapple 100 5 2
Moe Skeeto 200 5 6
Rusty Chain
Stu Pitt
Val Crow
Neil Down
Anita Bath UN
UN 3 5
200 6 3
PPM 2 7
10 4
PPM 5 7
200 4 5
UN 5 2
UN 7 4
6 9
8 5
6 7
4 3
3 10 5 2
You MUST ensure that you are not using “magic numbers” in your code. You should add appropriate definitions to phoneNetwork.h for all cost amounts minute-limit values and tax amounts.
Make sure that your code compiles, runs and produces the correct output. Hand this test code in with your assignment.
IMPORTANT SUBMISSION INSTRUCTIONS:
Submit all your .c and .h source code files as individual files (i.e., DO NOT TAR/RAR/ZIP/COMPRESS anything):
1. A Readme text file containing
-
your name and studentNumber
-
a list of source files submitted
• any specific instructions for compiling and/or running your code
2. All of your .c source files and all other files needed for testing/running your programs.
The code MUST compile and run on the course VM. You WILL lose marks on this assignment if any of your files are missing. So, make sure that you hand in the correct files and version of your assignment. You will also lose marks if your code is not written neatly with proper indentation and containing a reasonable number of comments.
