typedef struct  {
    short           level;   /* fill/empty level of buffer */
    unsigned        flags;   /* File status flags */
    char            fd;      /* File descriptor */
    unsigned char   hold;    /* Ungetc char if no buffer */
    short           bsize;   /* Buffer size */
    unsigned char   *buffer; /* Data transfer buffer */
    unsigned char   *curp;   /* Current active pointer */
    unsigned        istemp;  /* Temporary file indicator */
    short           token;   /* Used for validity checking */
} FILE;                      /* This is the FILE object */



#define _F_RDWR 0x0003 /* Read/write flag      */
#define _F_READ 0x0001 /* Read only file       */
#define _F_WRIT 0x0002 /* Write only file      */
#define _F_BUF  0x0004 /* Malloc'ed Buffer data */
#define _F_LBUF 0x0008 /* line-buffered file   */
#define _F_ERR  0x0010 /* Error indicator      */
#define _F_EOF  0x0020 /* EOF indicator        */
#define _F_BIN  0x0040 /* Binary file indicator */
#define _F_IN   0x0080 /* Data is incoming     */
#define _F_OUT  0x0100 /* Data is outgoing     */
#define _F_TERM 0x0200 /* File is a terminal   */