BSD 2 development

[unix-history] / .ref-BSD-1 / s7 / Ttyn.c

#
#
/*
* Ttyn - a fast version of ttyn which hashes major minor device numbers
*
* Bill Joy UCB August 17, 1977
*
* This routine can be called instead of calling 'ttyn' and stats
* the specified unit, then looking in a table to determine
* the unit number.  If the given unit is not in the table the standard
* 'ttyn' is called to get the answer.
*
* Generated:   Fri Nov  4 15:08:27 1977
* No. ttys:    79
*/

static  struct T {
       char    Tmajor;
       char    Tfirst;
       char    *Tttys;
       char    Tlast;
} Tttyinfo[] {
       0,      0,      "845=x_%!#0123679.",    16,
       14,     0,      "ABCDEFGHIJKLxNOPQRSTUVWXYZ\024\025\026\027\030\031abcdefghijklmnopqrstuvwyz+-,\001\002\003\005",       63,
};

#define NMAJDEV 2

struct  Stat {
       char    xminor, xmajor;
       int     inumber, flags;
       char    nlinks, uid, gid, size0;
       int     size1;
       char    dminor, dmajor;
       int     addr1[7];
       long    actime, modtime;
};

Ttyn(unit)
       int unit;
{
       register struct T *tp;
       struct Stat stbuf;

       if (fstat(unit, &stbuf))
               return ('x');
       for (tp = &Tttyinfo; tp < &Tttyinfo[NMAJDEV]; tp++)
               if (stbuf.dmajor == tp->Tmajor && stbuf.dminor >= tp->Tfirst && stbuf.dminor <= tp->Tlast)
                       return (tp->Tttys[stbuf.dminor - tp->Tfirst]);
       return (ttyn(unit));
}