+#if USE_RWOPS
+# include <SDL.h>
+typedef SDL_RWops *filedesc_t;
+# define FILEDESC_INVALID NULL
+# define FILEDESC_ISVALID(fd) ((fd) != NULL)
+# define FILEDESC_READ(fd,buf,count) ((fs_offset_t)SDL_RWread(fd, buf, 1, count))
+# define FILEDESC_WRITE(fd,buf,count) ((fs_offset_t)SDL_RWwrite(fd, buf, 1, count))
+# define FILEDESC_CLOSE SDL_RWclose
+# define FILEDESC_SEEK SDL_RWseek
+static filedesc_t FILEDESC_DUP(const char *filename, filedesc_t fd) {
+ filedesc_t new_fd = SDL_RWFromFile(filename, "rb");
+ if (SDL_RWseek(new_fd, SDL_RWseek(fd, 0, RW_SEEK_CUR), RW_SEEK_SET) < 0) {
+ SDL_RWclose(new_fd);
+ return NULL;
+ }
+ return new_fd;
+}
+# define unlink(name) Con_DPrintf("Sorry, no unlink support when trying to unlink %s.\n", (name))
+#else
+typedef int filedesc_t;
+# define FILEDESC_INVALID -1
+# define FILEDESC_ISVALID(fd) ((fd) != -1)
+# define FILEDESC_READ read
+# define FILEDESC_WRITE write
+# define FILEDESC_CLOSE close
+# define FILEDESC_SEEK lseek
+static filedesc_t FILEDESC_DUP(const char *filename, filedesc_t fd) {
+ return dup(fd);
+}
+#endif
+