Build Your Own wc Tool (c++)

This challenge is to build your own version of the Unix command line tool wc: Instructions

This tool counts the number of lines, words, bytes and characters in given files or from standard input.

I have not worked with C++ in years, so this was a nice opportunity to refresh my skills.

Build executable

Running one following commands in a terminal, will show a help screen on how to pass arguments to the scripts

• Cross platform python build.py
• Linux ./build.sh
• Windows ./build.bat (not tested)

Usage

Usage: ccwc [OPTION]... [FILES]...

Count characters, words, and lines in given files.

Options:
        -h              Show this help message
        -c              Count bytes
        -l              Count lines
        -w              Count words
        -m              Count characters

If no FILES specified, read standard input.
e.g. ls | ccwc
to quit stdin input, type :q

Things learned

loop over arguments

std::copy(argv, argv + argc, std::ostream_iterator<char *>(std::cout, "\n"));

open / close file

std::ifstream input_file(file_name, std::ios::in);
if (!input_file.is_open())
{
    std::cout << "File not found : " << file_name << std::endl;
    return 4;
}
input_file.close();

count bytes in file

input_file.seekg(0, std::ios::end);
std::cout << "File size: " << input_file.tellg() << " bytes" << std::endl;

open file in UTF-8 encoding

• as current locale did not recognize multibyte characters when using the -c option, reading in the file had to be in UTF-8

std::wifstream inputFile;

void openFile(std::string& filename) {
    file::inputFile.open(filename, std::ios::in);

    if (!inputFile.is_open())
    {
        std::cout << "File not found : " << filename << std::endl;
        return;
    }
    // Use UTF-8 encoding
    inputFile.imbue(std::locale(inputFile.getloc(), new std::codecvt_utf8<wchar_t>));
};

standard input

• write a temporary file to the filesystem's temporary directory from stdin
• clean up after running

build process

• Convert generated MAKEFILE to CMakeLists.txt
• Write simple build scripts in bash and batch
• rewrite CMakeLists.txt manually, with the help of CMake Workshop
• rewrite bash file to automate the build process
• create a python script to automate the build process

Add unit tests

• Simple tests with ctest
• Rewrite unit tests using Google Test
• Streamline the global test environment