/*      Improved c-version of tp?.s
 *      Implements update and replace for Magtape.
 *
 *      M. Ferentz
 *      Brooklyn College of CUNY
 *
 *      September 1976
 */

#define MDIRENT 2500    /* Sized to maximum core available (was 2776) */
                        /* Max number depends on efficiency of your C compiler;
                         * 2776 may be too high.
                         * Also depends on max core/process.
                         */
#define DIRSIZE 16
#define tapsiz  32767

#define tapeblk &tpentry[0]
#define tapeb   &tpentry[0]

struct  tent    {       /* Structure of a tape directory block */
        char    pathnam[32];
        int     mode;
        char    uid;
        char    gid;
        char    spare;
        char    size0;
        int     size1;
        int     time[2];         /* timen == time[n] */
        int     tapea;          /* tape address */
        int     unused[8];
        int     cksum;
}       tpentry[8];

struct  dent {  /* in core version of tent with "unused" removed
                 * and pathname replaced by pointer to same in a
                 * packed area (nameblock).
                 */
        char    *d_namep;
        int     d_mode;
        char    d_uid;
        char    d_gid;
        char    d_spare;
        char    d_size0;
        int     d_size1;
        int     d_time[2];
        int     d_tapea;
};

/*  The structure below uses all available core.  Names are stored
 *  backwards starting from the end.  Directory entries are stored
 *  starting at dir[0].  Blocks for directory entries are allocated
 *  eight at a time, corresponding to one block on the tape.  Checks
 *  for overlapping give "Out of core" fatal error message.
 */

struct  dent    dir[MDIRENT];

struct {
        int     s_skip[2];
        int     s_flags;
        char    s_nlinks;
        char    s_uid;
        char    s_gid;
        char    s_size0;
        int     s_size1;
        int     s_addr[8];
        int     s_active[2];
        int     s_modtime[2];
        } statb;

/**/

char    map[4096];
int     catlb[10];
char    name[32];
char    name1[32];
char    mt[]    ;
char    nrw_mt[] ;
char    backup[] ;

int     narg, rnarg;
char    **parg;
int     wseeka,rseeka;
int     fio;
int     backio;
int     ndirent, ndentd8;
char    *edir;
struct  dent *lastd;
int     endtape;        /* number of blocks before file mark */
                        /* Used with improved driver for speed */
int     (*command)();

char    *nptr;

int     flags;          /* default is flu */

#define flc     0001
#define flf     0002
#define fli     0004
#define flu     0020
#define flv     0040
#define flw     0100
#define flo     01000   /* 'old'-style directory */

struct { int integer; };