Description
Across Translation Units
In this workshop, you implement aspects of linkage, storage duration, namespaces, guards, and
operating system interfaces.
LEARNING OUTCOMES
Upon successful completion of this workshop, you will have demonstrated the abilities
• to declare a local variable that remains in memory for the lifetime of the program
• to guard a class definition from repetition
• to access a variable defined in a different translation unit
• to receive program arguments from the command line
• to upgrade code to accept and manage a user-defined string of any length
SUBMISSION POLICY
The in-lab section is to be completed during your assigned lab section. It is to be completed
and submitted by the end of the workshop period. If you attend the lab period and cannot
complete the in-lab portion of the workshop during that period, ask your instructor for
permission to complete the in-lab portion after the period. If you do not attend the workshop,
you can submit the in-lab section along with your at-home section (see penalties below). The
at-home portion of the lab is due on the day that is four days after your scheduled in-lab
workshop (23:59:59) (even if that day is a holiday).
All your work (all the files you create or modify) must contain your name, Seneca email and
student number.
You are responsible to back up your work regularly.
Late Submission Penalties:
• In-lab portion submitted late, with at-home portion: 0 for in-lab. Maximum of 7/10 for the
entire workshop.
• If any of in-lab, at-home or reflection portions is missing, the mark for the workshop will be
0/10.
SPECIFICATIONS – IN LAB
This workshop consists of three modules:
• w1
• process (supplied)
• String
Enclose all your source code within the sict namespace and include the necessary guards in
each header file. For the in-lab part, your String class should store no more than 3 characters
excluding the null terminator. The output from your executable running Visual Studio with the
following command line arguments should look like
Command Line : C:\Users\…\Debug\w1 in_lab.exe oop345 btp305
3: oop
4: btp
w1 Module
Your w1 module consists of a main() function and an unmodifiable variable of global scope that
defines the integer value for the next item in a list.
The main() function
• receives a set of C-style null-terminated strings from the command line
• echoes the set of the strings to standard output separated by a single space on one line
• inserts the error message “***Insufficient number of arguments***” if the user has not
entered any string on the command line and passes control to the operating system
with a return value of 1.
• calls the process function for each string and passes the address of that string as the
only argument.
• passes control to the operating system with a return value of 0.
process Module
The process module is supplied and you do not need to change its header or implementation
files. The implementation file defines a single function named process() that receives the
address of an unmodifiable C-style null terminated string, constructs a String object from the Cstring and inserts that object into standard output followed by a newline.
String Module
Your String module defines a class named String that holds a C-style null-terminated string of
up to 3 characters excluding the null byte terminator. The class includes the following member
and helper functions:
• a one-argument constructor that receives the address of an unmodifiable C-style nullterminated string and copies the string at that address into an instance variable. Check
for receipt of the null address and store an empty string in that case.
• a query named display() that receives a reference to an std::ostream object and inserts
the string stored in the instance variable.
• a helper non-friend operator that inserts the saved string into the left operand. This
operator inserts an item number followed by a colon and a single space as shown in the
output example above. Your function uses a local variable to store the current item
number and starts with the value of a global variable named INITIAL and defined in
another translation unit. Your function inserts the string associated with the right
operand and increments the current item number after the insertion.
Do not use the string class of the standard library in this workshop. Use the cstring functions.
In-Lab Submission (30%)
To test and demonstrate execution of your program use the same data as shown in the output
example above.
Upload your source code to your matrix account. Compile and run your code using the latest
version of the gcc compiler and make sure that everything works properly.
Then, run the following command from your account: (replace profname.proflastname with
your professor’s Seneca userid)
~profname.proflastname/submit 345XX_w1_lab
and follow the instructions. Replace XX with the section letter(s) specified by your instructor.
SPECIFICATIONS – AT HOME
For this part of the workshop, upgrade your String class to manage a C-style null-terminated
string of any length. Do not change your other modules.
Reflection
Study your final solution, reread the related parts of the course notes, and make sure that you
have understood the concepts covered by this workshop. This should take no less than 30
minutes of your time. Explain in your own words what you have learned in completing this
workshop. Include in your explanation but do not limit it to the following points (40%):
• the difference between internal and external linkage using examples from your code
• the execution effect of the code in the process() function that creates the String object
which is inserted into standard output (which member function(s) does this code call)
• the changes that you made in upgrading your String class.
Include all corrections to the Quiz you have received (30%).
At-Home Submission (70%)
To test and demonstrate execution of your program use the same data as shown in the output
example above.
Upload your source code to your matrix account. Compile and run your code using the latest
version of the gcc compiler and make sure that everything works properly.
Then, run the following command from your account: (replace profname.proflastname with
your professor’s Seneca userid)
~profname.proflastname/submit 345XX_w1_home
and follow the instructions. Replace XX with the section letter(s) specified by your instructor.
