/*
 * simple hacked-up program to show (in hexadecimal) the bit representation
 * of a floating-point number.
 * bytes are printed in memory order, which for little-endian architectures
 * is least-significant first.
 */
#include <stdio.h>
#include <stdlib.h>

void show_bytes(FILE * out, const void *bytes, const size_t sz);

int main(int argc, char *argv[]) {
    if (argc < 2) {
        fprintf(stderr, "usage %s number\n", argv[0]);
        return EXIT_FAILURE;
    }
    char * endptr;
    double d = strtod(argv[1], &endptr);
    if (*endptr != '\0') {
        fprintf(stderr, "not numeric\n");
        return EXIT_FAILURE;
    }
    float f = d;
    fprintf(stdout, "input value %g\n", d);
    fprintf(stdout, "as double:  ");
    show_bytes(stdout, &d, sizeof d);
    fprintf(stdout, "\n");
    fprintf(stdout, "as float:  ");
    show_bytes(stdout, &f, sizeof f);
    fprintf(stdout, "\n");
    return EXIT_SUCCESS;
}
void show_bytes(FILE * out, const void *bytes, const size_t sz) {
    unsigned char *uchar = (unsigned char *) bytes;
    for (size_t i = 0; i < sz; ++i) {
        fprintf(out, "%02x ", uchar[i]);
    }
}