Add extra info

Signed-off-by: Cristina Moraru <cristina-gabriela.moraru@cern.ch>

tapeserver/castor/tape/tapeserver/drive/README.st

@@ -112,3 +112,25 @@ GMT_ONLINE
 	cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)
 	STp->ready == ST_READY
 	same as above
+
+Additionally, are special functionalities based on other system calls than ioctl
+
+Snippet from Wrapper.hpp
+
+class realWrapper: public virtualWrapper {
+  public:
+
+    virtual DIR* opendir(const char *name) { return ::opendir(name); }
+    virtual struct dirent * readdir(DIR* dirp) { return ::readdir(dirp); }
+    virtual int closedir(DIR* dirp) { return ::closedir(dirp); }
+    virtual int readlink(const char* path, char* buf, size_t len) { return ::readlink(path, buf, len); }
+    virtual char * realpath(const char* name, char* resolved) { return ::realpath(name, resolved); }
+    virtual int open(const char* file, int oflag) { return ::open(file, oflag); }
+    ...
+    virtual ssize_t read(int fd, void* buf, size_t nbytes) { return ::read(fd, buf, nbytes); }
+    virtual ssize_t write(int fd, const void *buf, size_t nbytes) { return ::write(fd, buf, nbytes); }
+    virtual int close(int fd) { return ::close(fd); }
+    virtual int stat(const char * path, struct stat *buf) { return ::stat(path, buf); }
+    virtual castor::tape::tapeserver::drive::DriveInterface * 
+      getDriveByPath(const std::string &) { return NULL; }
+  };
\ No newline at end of file