Reminder

main.c

#include <libnotify/notify.h>
#include <time.h>

#define MAXLINE 1000

int cmp(char *, char *);
int detect_month(char[9], char[12][9]);
void cat(char *, char *);
void cpy(char *, char *);
int len(char *);
int get_line(const char *);
const char loc[75] = "/home/cenderme/.config/reminders";
const char *ploc = loc;

int main() {
  char *p_line = (char *)malloc(MAXLINE * sizeof(char));
  time_t tnow;
  double diff_t;
  struct tm *rem_time;
  int day, month, year, hour, minute, dd, hh, mm;
  int ups[100][3];
  char mon[9];
  char months[12][9] = {"January",   "February", "March",    "April",
                        "May",       "June",     "July",     "August",
                        "September", "October",  "November", "December"};
  char msg[500], m_str[3], msg_data[MAXLINE] = ""; // error if not defined
  while (1) {
    FILE *fp = fopen(ploc, "r");
    /* Go to the end of the header. */
    fseek(fp, 59, SEEK_SET);
    int n = get_line(ploc);
    /* n is limited at 1 because of the header of the configuration file. */
    while (n-- > 1) {
      cpy(msg_data, "");
      fscanf(fp, "%i %s %i %i:%i\t%i %i %i\t%[^\n]s", &day, mon, &year, &hour,
             &minute, &dd, &hh, &mm, msg);
      char *p_month = mon;
      int month = detect_month(mon, months);
      time(&tnow);
      rem_time = localtime(&tnow);
      rem_time->tm_year = year - 1900;
      rem_time->tm_mon = month;
      rem_time->tm_mday = day;
      rem_time->tm_hour = hour;
      rem_time->tm_min = minute;
      rem_time->tm_sec = 0;
      rem_time->tm_isdst = -1;
      int ret = mktime(rem_time);
      diff_t = difftime(ret, tnow);
      double foo_diff = diff_t / 60 / 60 / 24;
      if (foo_diff > 0) {
        if ((int)foo_diff > 0) {
          sprintf(m_str, "%i", (int)foo_diff);
          cat(msg_data, m_str);
          cat(msg_data, " days, ");
        }
        foo_diff = (foo_diff - (int)foo_diff) * 24;
        if ((int)foo_diff > 0) {
          sprintf(m_str, "%i", (int)foo_diff);
          cat(msg_data, m_str);
          cat(msg_data, " hours, ");
        }
        foo_diff = (foo_diff - (int)foo_diff) * 60;
        if ((int)foo_diff > 0) {
          sprintf(m_str, "%i", (int)foo_diff);
          if (len(msg_data) > 0)
            cat(msg_data, "and ");
          cat(msg_data, m_str);
          cat(msg_data, " minutes ");
        }
        cat(msg_data, "remaining...\n");
        cat(msg_data, msg);
        if (diff_t - mm * 60 - hh * 60 * 60 - dd * 60 * 60 * 24 < 0) {
          notify_init("reminder_app");
          NotifyNotification *foo = notify_notification_new(
              asctime(rem_time), msg_data,
              "/usr/share/icons/Adwaita/512x512/mimetypes/"
              "x-office-calendar-symbolic.png");
          notify_notification_show(foo, NULL);
          g_object_unref(G_OBJECT(foo));
          notify_uninit();
        }
      }
    }
    fclose(fp);
    sleep(1800);
  }
  return 0;
}

int cmp(char *s, char *t) {
  for (; *s == *t; s++, t++)
    if (*s == '\0')
      return 0;
  return *s - *t;
}

int detect_month(char data_month[9], char month_list[12][9]) {
  for (int i = 0; i != 12; i++) {
    int res = cmp(data_month, month_list[i]);
    if (res == 0)
      return i;
  }
  return 1;
}

void cpy(char *s, char *t) {
  while ((*s++ = *t++))
    ;
}

int len(char *s) {
  char *p = s;
  while (*p++)
    ;
  return --p - s;
  /*
     Alternative
     int n = 0;
     while (*s++)
     n++;
     return n;
     */
}

void cat(char *s, char *t) { cpy(s + len(s), t); }

int get_line(const char *s) {
  FILE *fp = fopen(s, "r");
  int n = 0, c;
  while ((c = fgetc(fp)) != EOF)
    if (c == '\n')
      ++n;
  fclose(fp);
  return n;
}