Version 1.4

Reworked channel changing: now it tracks the current ch. and resets only once. This makes the program to finish faster.
Added rolltime_down and percentage values to shutter structure: now the schedule file needs to contain a percentage column after the timestamp for lowering, and a rolltime needs to be defined for each shutter in the beginning of the program. When lowering shutters, there's a calculation to sleep until the desired percentage is reached, when the shutter is stopped
The way to deactivate shutters has changed: now you need to set the percentage to 0.

timing.c

@@ -0,0 +1,101 @@
+//
+// Created by lacko on 08/08/2021.
+//
+
+#include "idozites.h"
+#include <string.h>
+
+//function, which navigates the file, and stops at the label of today.
+int find_today (FILE *schedule)
+{
+  time_t t = time (NULL);
+  struct tm *now = localtime (&t);
+  char buffer[4] = {0};
+  while (find_next_day (schedule) == 1)
+    {
+      fgets (buffer, 4, schedule);
+      switch (now->tm_wday)
+        {
+          case 0:
+            if (strcasecmp (buffer, "VAS") == 0)
+              return 1;
+          break;
+          case 1:
+            if (strcasecmp (buffer, "HET") == 0)
+              return 1;
+          break;
+          case 2:
+            if (strcasecmp (buffer, "KED") == 0)
+              return 1;
+          break;
+          case 3:
+            if (strcasecmp (buffer, "SZE") == 0)
+              return 1;
+          break;
+          case 4:
+            if (strcasecmp (buffer, "CSU") == 0)
+              return 1;
+          break;
+          case 5:
+            if (strcasecmp (buffer, "PEN") == 0)
+              return 1;
+          break;
+          case 6:
+            if (strcasecmp (buffer, "SZO") == 0)
+              return 1;
+          break;
+        }
+    }
+  return 0;
+}
+
+int find_next_day (FILE *f)
+{
+  char c;
+  while (fscanf (f, "%c", &c) == 1)
+    {
+      if (c == '\n' && fgetc (f) == '\n')
+        return 1;
+    }
+  return 0;
+}
+
+void get_timing (shutter *r, FILE *schedule)
+{
+  int channel = 0;
+  while (channel != r->ch)
+    {
+      fscanf (schedule, "%*[^\n]s\n");
+      while (fscanf (schedule, "%d", &channel) != 1)
+        {
+          fscanf (schedule, "%*c");
+        }
+    }
+
+  while (fscanf (schedule, "%d:%d", &r->up.tm_hour, &r->up.tm_min) != 2)
+    fscanf (schedule, "%*c");
+
+  while (fscanf (schedule, "%d:%d", &r->down.tm_hour, &r->down.tm_min) != 2)
+    fscanf (schedule, "%*c");
+  fscanf (schedule, "%*[^\n]s\n");
+
+}
+
+buttons check_timing (shutter *r)
+{
+  if ((r->up.tm_hour == r->down.tm_hour) && (r->up.tm_min == r->down.tm_min))
+    return stop;
+  time_t t = time (NULL);
+  struct tm *now = localtime (&t);
+  if ((r->down.tm_hour == now->tm_hour) && (r->down.tm_min == now->tm_min))
+    {
+      return down;
+    }
+
+  if ((r->up.tm_hour == now->tm_hour) && (r->up.tm_min == now->tm_min))
+    {
+      return up;
+    }
+
+  return stop;
+}