Convert decimal GPS coordinates into sexagesimal

dec2sex.c

/* Compile with gcc -Wall -o dec2sex dec2sex.c -lm */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main (int argc, char **argv)
{
    int d, m, s, ms;
    double mm, ss;

/* prevent segfault in case no args */
    if (argc > 1)
    {
        d  = floor(atoi(argv[1]));
    }

/* continue algo */
    switch (argc)
    {
    case 2:
        /* decimal pure */
        m  = floor(mm = (atof(argv[1]) - d) * 60.0);
        break;
    case 3:
/* decimal minutes */
        m  = floor(mm = atof(argv[2]));
        break;
    default:
/* usage */
        puts ("\n  dec2sex is a decimal to sexagesimal (base 60) converter.");
        puts ("  dec2sex converts decimal degree coordinates into sexagesimal deg/m/s/mils");
        puts ("  use ABSOLUTE VALUE of any negative number, and garbage in = garbage out");
        puts ("  output is the coordinates in base 60");
        puts ("  dec2sex is not sexy.\n");

        puts ("  Usage: dec2sex XX.XXXXXX     (where X is some number)");
        puts ("     Or: dec2sex XX XX.XXXXXX  (for decimal minutes)");
        puts ("  Example: dec2sex 43.923056");
        puts ("  Output should be: 43°55\'23\"2ms");
        puts ("                    43°55.383362\'\n");
        printf("%i", argc);
        return (1);
        break;
    }
/* seconds and milli */
    s  = floor(ss = (mm - m) * 60.0);
    ms = round((ss - s) * 1000.0); // last one get rounded instead

/* out姤put */
    printf ("%i°%i\'%i\"%ims\n", d, m, s, ms);
    if (argc != 3)
    {
/* we aready has it */
        printf ("%i°%f\'\n", d, mm);
    }
    return (0);
}