utl::progressbar

progressbar adds configurable progress bars for CLI apps.

Definitions

// Configuration
void set_ostream(std::ostream &new_ostream);

// 'Percentage' progressbar
// > Proper progress bar, uses carriage return escape
// > sequence (\r) to render new states in the same spot
class Percentage {
public:
    Percentage(
        char done_char = '#',
        char not_done_char = '.',
        size_t bar_length = 30,
        double update_rate = 1e-2,
        bool show_time_estimate = true
    );
    
    start();
    set_progress(double percentage);
    finish();
};

// 'Ruler' progressbar
// > Primitive & lightweight progress bar, useful when
// > terminal has no proper support for escape sequences
class Ruler {
public:
    Percentage(
        char done_char = '#'
    );
    
    start();
    set_progress(double percentage);
    finish();
};

Methods

Configuration

progressbar::set_ostream()

Redirects output to given std::ostream. By default std::cout is used.

‘Percentage’ progressbar

progressbar::Percentage::Percentage(
     char done_char = '#',
     char not_done_char = '.',
     size_t bar_length = 30,
     double update_rate = 1e-2,
     bool show_time_estimate = true
)

Construct progress bar object with following options:

done_char - character used for “filled” part of the bar;
not_done_char - character used for “empty” part of the bar;
bar_length - bar width in characters;
update_rate - how often should the bar update its displayed percentage, 1e-2 corresponds to a single percent;
show_time_estimate - whether to show remaining time estimate (estimated through linear extrapolation);

Note 1: for terminals that do not support carriage return \r a less advanced progressbar::Ruler should be used.

Note 2: for terminals that cannot fit progress bar into a single line & don’t properly handle carriage return for wrapped lines, a less advanced progressbar::Ruler can be used. Such case is a rarity and depends on terminal implementation.

progressbar::Percentage::start();
progressbar::Percentage::set_progress(double percentage);
progressbar::Percentage::finish();

Start, update & finish progress bar display. Percentage is a value in $[0, 1]$ range, corresponding to a portion of total progress.

‘Ruler’ progressbar

progressbar::Ruler::Ruler(
     char done_char = '#'
)

Construct progress bar object with following options:

done_char - character used for “filled” part of the bar;

progressbar::Ruler::start();
progressbar::Ruler::set_progress(double percentage);
progressbar::Ruler::finish();

Start, update & finish progress bar display. Percentage is a value in $[0, 1]$ range, corresponding to a portion of total progress.

Examples

Using ‘Percentage’ progress bar

[ Run this code ]

using namespace utl;
using ms = std::chrono::milliseconds;

constexpr ms time(15'000);
constexpr ms tau(10);

// Create progress bar with style '[#####...] xx.xx%' and width 50
// that updates every 0.05%
auto bar = progressbar::Percentage('#', '.', 50, 0.05 * 1e-2, true);

std::cout << "\n- progressbar::Percentage -";

bar.start();
for (ms t(0); t <= time; t += tau) {
    std::this_thread::sleep_for(tau); // simulate some work
    const double percentage = double(t.count()) / time.count();

    bar.set_progress(percentage);
}
bar.finish();

Output (at some point in time):

- progressbar::Percentage -
[#################################.................] 67.45% (remaining: 7 sec)

Using ‘Ruler’ progress bar