956 typedef struct sqlite3_vfs sqlite3_vfs;  typedef
958 struct sqlite3_vfs {  struct
962   sqlite3_vfs *pNext;      /* Next registered VFS */  argument
965   int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,  argument
967   int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);  argument
968   int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);  argument
969   int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);  argument
970   void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);  argument
971   void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);  argument
972   void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);  argument
973   void (*xDlClose)(sqlite3_vfs*, void*);  argument
974   int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);  argument
975   int (*xSleep)(sqlite3_vfs*, int microseconds);  argument
976   int (*xCurrentTime)(sqlite3_vfs*, double*);  argument
977   int (*xGetLastError)(sqlite3_vfs*, int, char *);  argument
982   int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);  argument
987   int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);  argument
988   sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);  argument
989   const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);  argument
5260 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
5261 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
5262 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);