BSD 4_4 release

[unix-history] / usr / src / usr.bin / f77 / libI77 / sue.c

/*-
* Copyright (c) 1980 The Regents of the University of California.
* All rights reserved.
*
* This module is believed to contain source code proprietary to AT&T.
* Use and redistribution is subject to the Berkeley Software License
* Agreement and your Software Agreement with AT&T (Western Electric).
*/

#ifndef lint
static char sccsid[] = "@(#)sue.c       5.3 (Berkeley) 4/12/91";
#endif /* not lint */

/*
* sequential unformatted external read/write routines
*/

#include "fio.h"

extern int reclen;
LOCAL long recloc;
LOCAL char rsue[] = "read sue";
LOCAL char wsue[] = "write sue";

s_rsue(a) cilist *a;
{
       int n;
       reading = YES;
       if(n=c_sue(a,READ)) return(n);
       if(curunit->uwrt && ! nowreading(curunit)) err(errflag, errno, rsue)
       recpos = 0;
       if(fread(&reclen,sizeof(int),1,cf) == 1) return(OK);
       if(feof(cf))
       {       curunit->uend = YES;
               err(endflag, EOF, rsue)
       }
       clearerr(cf);
       err(errflag, errno, rsue)
}

s_wsue(a) cilist *a;
{
       int n;
       reading = NO;
       if(n=c_sue(a,WRITE)) return(n);
       if(!curunit->uwrt && ! nowwriting(curunit)) err(errflag, errno, wsue)
       reclen = 0;
       recloc=ftell(cf);
       fseek(cf,(long)sizeof(int),1);
       curunit->uend = NO;
       return(OK);
}

LOCAL
c_sue(a,flg) cilist *a;
{       int n;
       external = sequential = YES;
       formatted = NO;
       lfname = NULL;
       elist = NO;
       errflag = a->cierr;
       endflag = a->ciend;
       lunit = a->ciunit;
       if(not_legal(lunit)) err(errflag,F_ERUNIT,rsue+5)
       curunit = &units[lunit];
       if(!curunit->ufd && (n=fk_open(flg,SEQ,UNF,(ftnint)lunit)))
               err(errflag,n,rsue+5)
       cf = curunit->ufd;
       elist = YES;
       lfname = curunit->ufnm;
       if(curunit->ufmt) err(errflag,F_ERNOUIO,rsue+5)
       if(curunit->url) err(errflag,F_ERNOSIO,rsue+5)
       if(!curunit->useek) err(errflag,F_ERSEEK,rsue+5)
       return(OK);
}

e_wsue()
{       long loc;
       fwrite(&reclen,sizeof(int),1,cf);
       loc=ftell(cf);
       fseek(cf,recloc,0);
       fwrite(&reclen,sizeof(int),1,cf);
       fseek(cf,loc,0);
       return(OK);
}

e_rsue()
{
       fseek(cf,(long)(reclen-recpos+sizeof(int)),1);
       return(OK);
}