hexdump

hexdump.cpp

#include <algorithm>
#include <cctype>
#include <cinttypes>
#include <cstdint>
#include <cstdio>
#include <iostream>

int main(int argc, char *argv[])
{
    FILE *fp = stdin;
    uint8_t buffer[16] = {0};
    uintmax_t address = 0;
    size_t ncolumns = 16;
    for (size_t nbytes; nbytes = fread(buffer, sizeof(uint8_t), sizeof(buffer), fp); address += 0x10)
    {
        printf("%08" PRIxMAX ": ", address);
        auto grouping = 2;
        // Hexdump columns
        for (size_t idx = 0; idx != ncolumns; ++idx) {
            int spaces = (idx + 1) % grouping ? 0 : 1;
            if (idx < nbytes)
                printf("%02x" "%*s", buffer[idx], spaces, "");
            else
                printf("  %*s", spaces, "");
        }
        // ASCII column
        for (size_t idx = 0; idx != nbytes; ++idx) {
            printf("%c", isprint(buffer[idx]) ? buffer[idx] : '.');
        }
        printf("\n");
    };
    return 0;
}