BSD 4_2 release

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

/*
char id_due[] = "@(#)due.c      1.3";
*
* direct unformatted external i/o
*/

#include "fio.h"

char rdue[] = "read due";
char wdue[] = "write due";

s_rdue(a) cilist *a;
{
       int n;
       reading = YES;
       if(n=c_due(a,READ)) return(n);
       if(curunit->uwrt && ! nowreading(curunit)) err(errflag, errno, rdue);
       return(OK);
}

s_wdue(a) cilist *a;
{
       int n;
       reading = NO;
       if(n=c_due(a,WRITE)) return(n);
       curunit->uend = NO;
       if(!curunit->uwrt && ! nowwriting(curunit)) err(errflag, errno, wdue)
       return(OK);
}

c_due(a,flag) cilist *a;
{       int n;
       lfname = NULL;
       elist = NO;
       sequential=formatted=NO;
       recpos = reclen = 0;
       external = YES;
       errflag = a->cierr;
       endflag = a->ciend;
       lunit = a->ciunit;
       if(not_legal(lunit)) err(errflag,F_ERUNIT,rdue+5);
       curunit = &units[lunit];
       if (!curunit->ufd && (n=fk_open(flag,DIR,UNF,(ftnint)lunit)) )
               err(errflag,n,rdue+5)
       cf = curunit->ufd;
       elist = YES;
       lfname = curunit->ufnm;
       if (curunit->ufmt) err(errflag,F_ERNOUIO,rdue+5)
       if (!curunit->useek || !curunit->url) err(errflag,F_ERNODIO,rdue+5)
       if (fseek(cf, (long)((a->cirec-1)*curunit->url), 0) < 0)
               return(due_err(rdue+5));
       else
               return(OK);
}

e_rdue()
{
       return(OK);
}

e_wdue()
{/*     This is to ensure full records. It is really necessary. */
       int n = 0;
       if (curunit->url!=1 && recpos!=curunit->url &&
           (fseek(cf, (long)(curunit->url-recpos-1), 1) < 0
               || fwrite(&n, 1, 1, cf) != 1))
                       return(due_err(rdue+5));
       return(OK);
}