# /* */ /* * indirect driver for controlling tty. */ #include "param.h" #include "conf.h" #include "user.h" #include "tty.h" #include "proc.h" syopen(dev, flag) { if(u.u_ttyp == NULL) { u.u_error = ENXIO; return; } (*cdevsw[u.u_ttyd.d_major].d_open)(u.u_ttyd, flag); } syread(dev) { (*cdevsw[u.u_ttyd.d_major].d_read)(u.u_ttyd); } sywrite(dev) { (*cdevsw[u.u_ttyd.d_major].d_write)(u.u_ttyd); } sysgtty(dev, flag) { (*cdevsw[u.u_ttyd.d_major].d_sgtty)(u.u_ttyd, flag); }