UNIX 7th Ed. - /usr/src/libI77/due.c

   1: #include "fio.h"
   2: s_rdue(a) cilist *a;
   3: {
   4:     int n;
   5:     if(n=c_due(a,READ)) return(n);
   6:     reading=1;
   7:     if(curunit->uwrt) nowreading(curunit);
   8:     return(0);
   9: }
  10: s_wdue(a) cilist *a;
  11: {
  12:     int n;
  13:     if(n=c_due(a,WRITE)) return(n);
  14:     reading=0;
  15:     if(!curunit->uwrt) nowwriting(curunit);
  16:     return(0);
  17: }
  18: c_due(a,flag) cilist *a;
  19: {
  20:     if(!init) f_init();
  21:     if(a->ciunit>=MXUNIT || a->ciunit<0)
  22:         err(a->cierr,101,"startio");
  23:     recpos=sequential=formatted=0;
  24:     external=1;
  25:     curunit = &units[a->ciunit];
  26:     elist=a;
  27:     if(curunit->ufd==NULL && fk_open(flag,DIR,UNF,a->ciunit) ) err(a->cierr,104,"due");
  28:     cf=curunit->ufd;
  29:     if(curunit->ufmt) err(a->cierr,102,"cdue")
  30:     if(!curunit->useek) err(a->cierr,104,"cdue")
  31:     if(curunit->ufd==NULL) err(a->cierr,114,"cdue")
  32:     fseek(cf,(long)(a->cirec-1)*curunit->url,0);
  33:     curunit->uend = 0;
  34:     return(0);
  35: }
  36: e_rdue()
  37: {
  38:     if(curunit->url==1 || recpos==curunit->url)
  39:         return(0);
  40:     fseek(cf,(long)(curunit->url-recpos),1);
  41:     if(ftell(cf)%curunit->url)
  42:         err(elist->cierr,200,"syserr");
  43:     return(0);
  44: }
  45: e_wdue()
  46: {
  47:     return(e_rdue());
  48: }

Defined functions