enum

#define g2byte(x) (((x)[1]<<8) + (x)[0]) /* little-endian */
#define g3byte(x) (((x)[2]<<16) + ((x)[1]<<8) + (x)[0])
#define g4byte(x) (((x)[3]<<24) + ((x)[2]<<16) + ((x)[1]<<8) + (x)[0])

/* big endian */
#define b4byte(x) (((x)[0]<<24) + ((x)[1]<<16) + ((x)[2]<<8) + (x)[3])
#define b8byte(x) (((vlong)b4byte(x)<<32) | (u32int)b4byte((x)+4))
enum
{
OPERM = 0x3, /* mask of all permission types in open mode */
Nram = 512,
Maxbuf = 8192, /* max buffer size */
};

typedef struct Fid Fid;
typedef struct Ram Ram;

struct Fid
{
short busy;
short open;
short rclose;
int fid;
Fid *next;
char *user;
Ram *ram;
};

struct Ram
{
char busy;
char open;
char replete;
Ram *parent; /* parent directory */
Ram *child; /* first member of directory */
Ram *next; /* next member of file's directory */
Qid qid;
long perm;
char *name;
ulong atime;
ulong mtime;
char *user;
char *group;
vlong addr;
void *data;
vlong ndata;
};

enum
{
Pexec = 1,
Pwrite = 2,
Pread = 4,
Pother = 1,
Pgroup = 8,
Powner = 64,
};

typedef struct idmap {
char *name;
int id;
} Idmap;

typedef struct fileinf {
char *name;
vlong addr;
void *data;
vlong size;
int mode;
int uid;
int gid;
long mdate;
} Fileinf;

extern ulong path; /* incremented for each new file */
extern Ram *ram;
extern char *user;
extern Idmap *uidmap;
extern Idmap *gidmap;
extern int replete;
extern int blocksize;
void error(char*);
void *erealloc(void*, ulong);
void *emalloc(ulong);
char *estrdup(char*);
void populate(char *);
void dotrunc(Ram*);
void docreate(Ram*);
char *doread(Ram*, vlong, long);
void dowrite(Ram*, char*, long, long);
int dopermw(Ram*);
Idmap *getpass(char*);
char *mapid(Idmap*,int);
Ram *poppath(Fileinf fi, int new);
Ram *popfile(Ram *dir, Fileinf fi);
void popdir(Ram*);
Ram *lookup(Ram*, char*);