/* A system call that opens a file identified by name in a given mode, and
returns a file descriptor uniquely identifying that file.
*/
-_PDCLIB_fd_t _PDCLIB_open( char const * const filename, int mode );
+_PDCLIB_fd_t _PDCLIB_open( char const * const filename, unsigned int mode );
/* A system call that writes n characters to a file identified by given file
descriptor. Return the number of characters written.