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
– guard a class definition from repetition
– access a variable defined in a different translation unit
– receive program arguments from the command line
– upgrade code to accept and manage a user-defined string of any length
## *In-Lab*
This workshop consists of three modules:
– `w1` (partially supplied)
– `process` (supplied)
– `String`
Enclose all your source code within the `sdds` namespace and include the necessary guards in each header file.
### `w1` Module (partially supplied)
Finish the implementation of the `main` function, by completing the parts marked with `TODO`:
– write the prototype of the `main` function to receive a set of standard command line arguments
– echoes the set of arguments to standard output in the following format:
“`
1: first argument
2: second argument
3: third argument
4: …
“`
**Do not modify this module in any other place!**
### `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 C-style string 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 null-terminated 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 **free helper** insertion operator that inserts the saved string into the left operand. This operator should count how many times it has been called (by incrementing a counter), and prints this value to the screen as shown below. **Do not use global variables to store the counter!**
“`
COUNTER: STRING
“`
Do not use the `string` class of the standard library in this workshop. Use only `cstring` functions where necessary.
In the namespace `sdds`, this module should contain a *global variable* named `g_maxSize` of type `unsigned int` (an integer that has non-negative values). Initialize it with `3`. Declare the variable in the header and define it in the implementation file.
### Sample Output
When the program is started with the command:
“`
w1.exe Welcome to C++!
“`
the output should look like:
“`
Command Line:
1: w1.exe
2: Welcome
3: to
4: C++!
——————
Global variable:
——————
Old Value: 3
New Value: 4
——————
——————
Processing:
——————
1: Wel
2: to
3: C++
——————
“`
### 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 `g++` compiler (available at `/usr/local/gcc/9.1.0/bin/g++`) 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 345XXX_w1_lab
“`
and follow the instructions. Replace XXX with the section letter(s) specified by your instructor.
**:warning:Important:** Please note that a successful submission does not guarantee full credit for this workshop. If the professor is not satisfied with your implementation, your professor may ask you to resubmit. Resubmissions will attract a penalty.
## *At-Home*
For this part of the workshop, upgrade your `String` class to manage a C-style null-terminated string of any length. When a new instance is created, the custom constructor should accept at most `g_maxSize` characters (excluding the null terminator). No other modules need to be changed.
### Sample Output
When the program is started with the command:
“`
w1.exe Welcome to C++!
“`
the output should look like:
“`
Command Line:
1: w1.exe
2: Welcome
3: to
4: C++!
——————
Global variable:
——————
Old Value: 3
New Value: 4
——————
——————
First processing:
——————
1: Welc
2: to
3: C++!
——————
——————
Second processing:
——————
4: Welco
5: to
6: C++!
——————
Welcome
Welcome
School of Software Design and Data Science
7: Welcome
8: Welcome
9: Welcome
“`
