* use single imdb_t->flags instead separate write and caps members

* make caps as bit mask
* prepare for imdb_open returns handle

src/database.c

@@ -66,26 +66,25 @@ int imdb_open(imdb_db_t *db, const char *path, int write)
   ssize_t bytes = 0;
   struct stat st;
   char buf[IMDB_REC_LEN] = "\0";
+  int flags = 0, fd = -1;
+  char *p;
 
   assert(db   != NULL);
   assert(path != NULL);
 
   memset(db, 0x0, sizeof(imdb_db_t));
-  db->fd = -1;
 
   errno = 0;
-  if (stat(path, &st) == -1) {
+  if (stat(path, &st) < 0) {
     strncpy(db->error, strerror(errno), sizeof(db->error));
     return -1;
   }
 
   errno = 0;
-  if ((db->fd = open(path, write ? O_RDWR : O_RDONLY)) == -1) {
+  if ((fd = open(path, write ? O_RDWR : O_RDONLY)) < 0) {
     strncpy(db->error, strerror(errno), sizeof(db->error));
     return -1;
   }
-  db->write = write;
-  strncpy(db->path, path, sizeof(db->path));
 
   DB_READ(db, buf, IMDB_REC_LEN, 0);
 
@@ -105,7 +104,25 @@ int imdb_open(imdb_db_t *db, const char *path, int write)
     strncpy(db->error, "Can't read database capabilities", sizeof(db->error));
     return -1;
   }
-  memcpy(db->caps, buf + 16, sizeof(char) * 8);
+
+  if (write)
+    flags |= IMDB_FLAG_WRITE;
+
+  p = buf + 16;
+  for (size_t i = 0; i < 8 && *p != '\0'; p++) {
+    switch (*p) {
+      case 'M' : flags |= IMDB_CAP_BITMAP; break;
+      case 'C' : flags |= IMDB_CAP_COLORS; break;
+      case 'R' : flags |= IMDB_CAP_RATIO;  break;
+      case ';' : i = 9; /* end of flags */ break;
+      default: /* ignore */ break;
+    }
+  }
+
+  db->fd    = fd;
+  db->flags = flags;
+
+  strncpy(db->path, path, sizeof(db->path));
 
   return 0;
 }

src/database.h

@@ -4,12 +4,20 @@
 #define IMDB_REC_LEN 48
 #define IMDB_VERSION  2
 
+/* runtime flags */
+#define IMDB_FLAG_WRITE    1 << (0 + 0)
+
+/* database capabilities */
+#define IMDB_CAP_BITMAP    1 << (8 + 0)
+#define IMDB_CAP_COLORS    1 << (8 + 1)
+#define IMDB_CAP_RATIO     1 << (8 + 2)
+/* 3 used, 5 reserved */
+
 typedef struct {
   int fd;
-  int write;
+  int flags;
   char path[PATH_MAX];
   char error[256];
-  char caps[8];
 } imdb_db_t;
 
 /**
@@ -20,11 +28,6 @@ typedef struct {
 24-48 : padding with null's
 */
 
-#define CAP_OFF_BITMAP  0
-#define CAP_OFF_COLORS  1
-#define CAP_OFF_RATIO   2
-/* 3 used, 5 reserved */
-
 /**
   Database record format - fixed length, 48 bytes