Convert sexagesimal GPS coordinates into decimal

sex2dec.c

/* Compile with gcc -Wall -o sex2dec sex2dec.c */

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

int main (int argc, char **argv)
{
    if (argc == 5)
    {
        printf ("%f\n", atoi(argv[1])
            + atoi(argv[2]) / 60.0
            + atoi(argv[3]) / 3600.0
            + atoi(argv[4]) / 216000.0);
        return (0);
    }else if (argc == 3)
    {
        printf ("%f\n", atoi(argv[1])
            + atof(argv[2]) / 60.0);
        return (0);
    }else
    {
        puts ("\n  sex2dec is a sexagesimal (base 60) to decimal converter.");
        puts ("  sex2dec converts sexagesimal based deg/m/s/mils or deg/m.mmm coordinates into");
        puts ("    decimal.");
        puts ("  use ABSOLUTE VALUE of any negative number, and garbage in = garbage out");
        puts ("  output is the coordinates in base 10");
        puts ("  sex2dec is not sexy.\n");

        puts ("  Usage: sex2dec degrees minutes seconds milliseconds");
        puts ("     Or: sex2dec degrees minutes.fraction");
        puts ("  Example: sex2dec 43 55 23 0");
        puts ("  Output should be: 43.923056\n");
        return (1);
    }
}