_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.
+ descriptor. Return the number of characters actually written, or zero if
+ an error occured.
*/
_PDCLIB_size_t _PDCLIB_write( _PDCLIB_fd_t fd, char const * buffer, _PDCLIB_size_t n );
must still be accessible by old name.
*/
int _PDCLIB_rename( const char * old, const char * new );
+
+/* A system call that returns one if the given file descriptor refers to an
+ interactive device, and zero otherwise.
+ */
+int _PDCLIB_isinteractive( _PDCLIB_fd_t fd );
+