#define Qroot	0 #define MSGMAX	((((8192+128)*2)+3) & ~3) extern char Enomem[];	/* out of memory */extern char Eperm[];		/* permission denied */extern char Enodev[];	/* no free devices */extern char Ehungup[];	/* i/o on hungup channel */extern char Eexist[];		/* file exists */extern char Enonexist[];	/* file does not exist */extern char Ebadcmd[];	/* bad command */extern char Ebadarg[];	/* bad arguments */ typedef uvlong	Path;typedef struct Styxserver	Styxserver;typedef struct Styxops Styxops;typedef struct Styxfile Styxfile;typedef struct Client Client;typedef struct Fid Fid; struct Styxserver{	Styxops *ops;	Path qidgen;	int connfd;	int needfile;	Client *clients;	Client *curc;	Styxfile *root;	Styxfile **ftab;	void	*priv;	/* private */}; struct Client{	Styxserver *server;	Client *next;	int		fd;	char	msg[MSGMAX];	uint		nread;		/* valid bytes in msg (including nc)*/	int		nc;			/* bytes consumed from front of msg by convM2S */	char	data[MSGMAX];	/* Tread/Rread data */	int		state;	Fid		*fids;	char		*uname;	/* uid */	char		*aname;	/* attach name */	void		*u;}; struct Styxops{	char *(*newclient)(Client *c);	char *(*freeclient)(Client *c); 	char *(*attach)(char *uname, char *aname);	char *(*walk)(Qid *qid, char *name);	char *(*open)(Qid *qid, int mode);	char *(*create)(Qid *qid, char *name, int perm, int mode);	char *(*read)(Qid qid, char *buf, ulong *n, vlong offset);	char *(*write)(Qid qid, char *buf, ulong *n, vlong offset);	char *(*close)(Qid qid, int mode);	char *(*remove)(Qid qid);	char *(*stat)(Qid qid, Dir *d);	char *(*wstat)(Qid qid, Dir *d);}; struct Styxfile{	Dir	d;	Styxfile *parent;	Styxfile *child;	Styxfile *sibling;	Styxfile *next;	int ref;	int open;	void	*u;}; char *styxinit(Styxserver *server, Styxops *ops, char *port, int perm, int needfile);char *styxwait(Styxserver *server);char *styxprocess(Styxserver *server);char *styxend(Styxserver *server); Client *styxclient(Styxserver *server); Styxfile *styxaddfile(Styxserver *server, Path pqid, Path qid, char *name, int mode, char *owner);Styxfile *styxadddir(Styxserver *server, Path pqid, Path qid, char *name, int mode, char *owner);int styxrmfile(Styxserver *server, Path qid);Styxfile *styxfindfile(Styxserver *server, Path qid); int	styxperm(Styxfile *file, char *uid, int mode);long styxreadstr(ulong off, char *buf, ulong n, char *str);Qid styxqid(int path, int isdir);void *styxmalloc(int n);void styxfree(void *p);void styxdebug(void);void styxsetowner(char*);