Simple Linux console application for printing progress of per line output items (i.e progress of printing sha sums of listed files via parallels)

progress.cpp

#include <cstdio>
#include <cstdlib>
#include <cstring>

#define eprintf(...) fprintf(stderr, __VA_ARGS__)


int main(int argc, const char* argv[])
{
    if (argc != 2)
    {
        eprintf("Usage: %s <number of lines>\n", argv[0]);
        return 1;
    }


    long total_lines = atol(argv[1]);
    long current_line = 0;
    fprintf(stderr, "Progress: %ld / %ld (%.02f%%)\r", current_line, total_lines, current_line / double(total_lines) * 100.f);

    int BUFFER_SIZE = 1024;
    char* buffer = new char[BUFFER_SIZE];


    while (!feof(stdin))
    {
        if (!fgets(buffer, BUFFER_SIZE, stdin))
            break;
        
        int l = strlen(buffer);
        if (l == BUFFER_SIZE - 1)
            printf("%*s", l, buffer);
        else
        {
            ++current_line;
            fprintf(stderr, "Progress: %ld / %ld (%.02f%%)\r", current_line, total_lines, current_line / double(total_lines) * 100.f);
            printf("%*s", l, buffer);
        }
        
    }
    fprintf(stderr, "Complete%*s\n", 200, " ");

    delete [] buffer;

    return 0;
}