#include <stdlib.h>#include <stdio.h>#include <unistd.h>#include <time.h>/* See http://en.wikipedia.org/wiki/Binary_numeral_system#Decimal for the *//* principle of the conversion algorithm used here. */void dec2binstr(int in, char *out, int outlen) { char *outend = out + outlen; /* Initialize a pointer to work the string */ *outend = '\0'; /* from behind and insert the terminating */ outend--; /* ASCII 0. */ while (outend > out) { while (in) { switch (in % 2) { case 0: *outend = '0'; break; case 1: *outend = '1'; break; } in = in / 2; outend--; } *outend = '0'; outend--; } *outend = '0'; /* Don't outend--; after the last pass, so it's not left */ /* pointing to an invalid memory location. Could this be */ /* the fix for the problem with gcc 4? */}int main(int argc, char *argv[]) { int opt_seconds = 0; int opt_decimal = 0; char inarg; while ((inarg = getopt (argc, argv, "sd")) != -1) switch (inarg) { case 's': opt_seconds = 1; break; case 'd': opt_decimal = 1; break; } time_t curtime; struct tm *timedata; curtime = time(0); timedata = localtime(&curtime); int twelve_hour; char bin_hour[5]; /* only four digits for the hour */ char bin_min[7]; char bin_sec[7]; twelve_hour = timedata->tm_hour; if (twelve_hour > 12) { twelve_hour -= 12; } dec2binstr(twelve_hour, bin_hour, 4); dec2binstr(timedata->tm_min, bin_min, 6); if (opt_seconds) { dec2binstr(timedata->tm_sec, bin_sec, 6); } /* I thought a lot about how to do this and I've decided to rather go * * with a bunch of printf(); lines than to do some kind of smartass * * printf("%s %s\n", bin_min, dec_min) black voodoo thing, because * * that would involve initializing an empty dec_min string and then * * filling it if needed. And since this is C and not Perl, that would * * be Shooting Myself In The Foot(tm) big time. */ if (opt_decimal) { if (timedata->tm_hour < 10) { printf(" %s (0%ih)\n", bin_hour, timedata->tm_hour); } else { printf(" %s (%ih)\n", bin_hour, timedata->tm_hour); } if (timedata->tm_min < 10) { printf("%s (0%im)\n", bin_min, timedata->tm_min); } else { printf("%s (%im)\n", bin_min, timedata->tm_min); } if (opt_seconds) { if (timedata->tm_sec < 10) { printf("%s (0%is)\n", bin_sec, timedata->tm_sec); } else { printf("%s (%is)\n", bin_sec, timedata->tm_sec); } } } else { printf(" %s\n%s\n", bin_hour, bin_min); if (opt_seconds) { printf("%s\n", bin_sec); } } return 0;}