VAX .s routines only work with the old stdio

[unix-history] / usr / src / lib / libc / stdio / wsetup.c

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* %sccs.include.redist.c%
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)wsetup.c    5.2 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <stdio.h>
#include <stdlib.h>
#include "local.h"

/*
* Various output routines call wsetup to be sure it is safe to write,
* because either _flags does not include __SWR, or _buf is NULL.
* _wsetup returns 0 if OK to write, nonzero otherwise.
*/
__swsetup(fp)
       register FILE *fp;
{
       /* make sure stdio is set up */
       if (!__sdidinit)
               __sinit();

       /*
        * If we are not writing, we had better be reading and writing.
        */
       if ((fp->_flags & __SWR) == 0) {
               if ((fp->_flags & __SRW) == 0)
                       return (EOF);
               if (fp->_flags & __SRD) {
                       /* clobber any ungetc data */
                       if (HASUB(fp))
                               FREEUB(fp);
                       fp->_flags &= ~(__SRD|__SEOF);
                       fp->_r = 0;
                       fp->_p = fp->_bf._base;
               }
               fp->_flags |= __SWR;
       }

       /*
        * Make a buffer if necessary, then set _w.
        */
       if (fp->_bf._base == NULL)
               __smakebuf(fp);
       if (fp->_flags & __SLBF) {
               /*
                * It is line buffered, so make _lbfsize be -_bufsize
                * for the putc() macro.  We will change _lbfsize back
                * to 0 whenever we turn off __SWR.
                */
               fp->_w = 0;
               fp->_lbfsize = -fp->_bf._size;
       } else
               fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size;
       return (0);
}