Bell 32V development

[unix-history] / usr / src / libI77 / due.c

#include "fio.h"
s_rdue(a) cilist *a;
{
       int n;
       if(n=c_due(a,READ)) return(n);
       reading=1;
       if(curunit->uwrt) nowreading(curunit);
       return(0);
}
s_wdue(a) cilist *a;
{
       int n;
       if(n=c_due(a,WRITE)) return(n);
       reading=0;
       if(!curunit->uwrt) nowwriting(curunit);
       return(0);
}
c_due(a,flag) cilist *a;
{
       if(!init) f_init();
       if(a->ciunit>=MXUNIT || a->ciunit<0)
               err(a->cierr,101,"startio");
       recpos=sequential=formatted=0;
       external=1;
       curunit = &units[a->ciunit];
       elist=a;
       if(curunit->ufd==NULL && fk_open(flag,DIR,UNF,a->ciunit) ) err(a->cierr,104,"due");
       cf=curunit->ufd;
       if(curunit->ufmt) err(a->cierr,102,"cdue")
       if(!curunit->useek) err(a->cierr,104,"cdue")
       if(curunit->ufd==NULL) err(a->cierr,114,"cdue")
       fseek(cf,(long)(a->cirec-1)*curunit->url,0);
       curunit->uend = 0;
       return(0);
}
e_rdue()
{
       if(curunit->url==1 || recpos==curunit->url)
               return(0);
       fseek(cf,(long)(curunit->url-recpos),1);
       if(ftell(cf)%curunit->url)
               err(elist->cierr,200,"syserr");
       return(0);
}
e_wdue()
{
       return(e_rdue());
}