UNIX 6th Ed. - /usr/sys/dmr/sys.c

   1: #
   2: /*
   3:  */
   4: 
   5: /*
   6:  *	indirect driver for controlling tty.
   7:  */
   8: #include "../param.h"
   9: #include "../conf.h"
  10: #include "../user.h"
  11: #include "../tty.h"
  12: #include "../proc.h"
  13: 
  14: syopen(dev, flag)
  15: {
  16:     register *tp;
  17: 
  18:     if(tp = syttyp())
  19:     (*cdevsw[tp->t_dev.d_major].d_open)(tp->t_dev, flag);
  20: }
  21: 
  22: syread(dev)
  23: {
  24:     register *tp;
  25: 
  26:     if(tp = syttyp())
  27:     (*cdevsw[tp->t_dev.d_major].d_read)(tp->t_dev);
  28: }
  29: 
  30: sywrite(dev)
  31: {
  32:     register *tp;
  33: 
  34:     if(tp = syttyp())
  35:     (*cdevsw[tp->t_dev.d_major].d_write)(tp->t_dev);
  36: }
  37: 
  38: sysgtty(dev, flag)
  39: {
  40:     register *tp;
  41: 
  42:     if(tp = syttyp())
  43:     (*cdevsw[tp->t_dev.d_major].d_sgtty)(tp->t_dev, flag);
  44: }
  45: 
  46: syttyp()
  47: {
  48:     register tp;
  49: 
  50:     tp = u.u_procp->p_ttyp;
  51:     if(tp == NULL)
  52:         u.u_error = ENXIO;
  53:     return(tp);
  54: }

Defined functions