#define _READ   0x0001  /* file opened for reading */
#define _WRITE  0x0002  /* file opened for writing */
#define _UNGET  0x0004  /* ungetc has been done */
#define _BIGBUF 0x0008  /* big buffer allocated */
#define _EOF    0x0010  /* EOF has occurred */
#define _SFERR  0x0020  /* error has occurred on this file */
#define _APPEND 0x0080  /* file opened for append */
#define _BINARY 0x0040  /* file is binary, skip CRLF processing */
#define _TMPFIL 0x0800  /* this is a temporary file */
#define _DIRTY  0x1000  /* buffer has been modified */
#define _ISTTY  0x2000  /* is console device */
#define _DYNAMIC 0x4000 /* FILE is dynamically allocated   */
#define _FILEEXT 0x8000 /* lseek with positive offset has been done */
#define _COMMIT 0x0001  /* extended flag: commit OS buffers on flush */

typedef struct
{
    char *name;
    unsigned int offset;
    int mode;
    int lock;
    int (*read)(const char *, void *, size_t, size_t, size_t *);
    int (*write)(const char*, const void *, size_t, size_t, size_t*);
}__io_handle;

extern __io_handle __io_tab[64];

int __io_alloc();
void __io_free(int handle);