Bits & Pieces

The libcifpp library offers some extra code that makes the life of developers a bit easier.

gzio

To work with compressed data files a std::streambuf implemenation was added based on the code in gxrio. This allows you to read and write compressed data streams transparently.

When working with files you can use cif::gzio::ifstream and cif::gzio::ofstream. The selection of whether to use compression or not is based on the file extension. If it is .gz gzip compression is used:

cif::gzio::ifstream file("my-file.txt.gz");

std::string line;
while (std::getline(file, line))
        std::cout << line << '\n';

Writing is equally easy:

cif::gzio::ofstream file("/tmp/output.txt.gz");
file << "Hello, world!";
file.close();

You can also use the cif::gzio::istream and feed it a std::streambuf object that may or may not contain compressed data. In that case the first bytes of the input are sniffed and if it is gzip compressed data, decompression will be done.

A progress bar

Applications based on libcifpp may have a longer run time. To give some feedback to the user running your application in a terminal you can use the cif::progress_bar. This class will display an ASCII progress bar along with optional status messages, but only if output is to a real TTY (terminal).

A progress bar is also shown only if the duration is more than two seconds. To avoid having flashing progress bars for short actions.

The progress bar uses an internal progress counter that starts at zero and ends when the max value has been reached after which it will be removed from the screen. Updating this internal progress counter can be done by adding a number of steps calling cif::progress_bar::consumed() or by setting the exact value for the counter by calling cif::progress_bar::progress().

Colouring output

It is also nice to emphasise some output in the terminal by using colours. For this you can create output manipulators using cif::coloured(). To write a string in white, and bold letters on a red background you can do:

using namespace cif::colour;
std::cout << cif::coloured("Hello, world!", white, red, bold) << '\n';