Converts a duration in seconds into a human readable string.

HumanReadableDuration.c

/**
 * HumanReadableDuration
 * 
 * Retruns a human readable duration for totalSeconds.
 * Make sure outputBuffer is big enough to hold the 
 * complete string incl. temrinate '\0' character.
 */
char* HumanReadableDuration(unsigned long totalSeconds, char* outputBuffer ) {

  if(outputBuffer) {
    char *workPos = outputBuffer;
    
    // Calculate the uptime in hors, minutes and seconds
    int uptimeDays    = (int)  (totalSeconds / (60 * 60 * 24L));
    int uptimeHours   = (int) ((totalSeconds / (60*60)) % 24);
    int uptimeMinutes = (int) ((totalSeconds / 60) % 60);
    int uptimeSeconds = (int)  (totalSeconds % 60);

    if(uptimeDays > 0) {
      *workPos++ = '[';
      
      if(uptimeDays > 9999) {
        *workPos++ = (uptimeDays / 10000) + '0';    
        uptimeDays -= 10000;
      }

      if(uptimeDays > 999) {
        *workPos++ = (uptimeDays / 1000) + '0';    
        uptimeDays -= 1000;
      }

      if(uptimeDays > 99) {
        *workPos++ = (uptimeDays / 100) + '0';    
        uptimeDays -= 100;
      }

      if(uptimeDays > 9) *workPos++ = (uptimeDays / 10) + '0';    
      *workPos++ = (uptimeDays % 10) + '0';    
      *workPos++ = ']';
      *workPos++ = ' ';      
    }
 
    *workPos++ = (uptimeHours / 10) + '0';
    *workPos++ = (uptimeHours % 10) + '0';
    *workPos++ = ':';

    *workPos++ = (uptimeMinutes / 10) + '0';
    *workPos++ = (uptimeMinutes % 10) + '0';
    *workPos++ = ':';

    *workPos++ = (uptimeSeconds / 10) + '0';
    *workPos++ = (uptimeSeconds % 10) + '0';

    *workPos = 0;
  }

  return outputBuffer;
}