gonzui

    1: /*      $OpenBSD: wsetup.c,v 1.7 2005/08/08 08:05:36 espie Exp $ */
    2: /*-
    3:  * Copyright (c) 1990, 1993
    4:  *      The Regents of the University of California.  All rights reserved.
    5:  *
    6:  * This code is derived from software contributed to Berkeley by
    7:  * Chris Torek.
    8:  *
    9:  * Redistribution and use in source and binary forms, with or without
   10:  * modification, are permitted provided that the following conditions
   11:  * are met:
   12:  * 1. Redistributions of source code must retain the above copyright
   13:  *    notice, this list of conditions and the following disclaimer.
   14:  * 2. Redistributions in binary form must reproduce the above copyright
   15:  *    notice, this list of conditions and the following disclaimer in the
   16:  *    documentation and/or other materials provided with the distribution.
   17:  * 3. Neither the name of the University nor the names of its contributors
   18:  *    may be used to endorse or promote products derived from this software
   19:  *    without specific prior written permission.
   20:  *
   21:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   22:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   23:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   24:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   25:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   26:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   27:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   28:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   29:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   30:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   31:  * SUCH DAMAGE.
   32:  */
   33: 
   34: #include <stdio.h>
   35: #include <stdlib.h>
   36: #include "local.h"
   37: 
   38: /*
   39:  * Various output routines call wsetup to be sure it is safe to write,
   40:  * because either _flags does not include __SWR, or _buf is NULL.
   41:  * _wsetup returns 0 if OK to write, nonzero otherwise.
   42:  */
   43: int
   44: __swsetup(FILE *fp)
   45: {
   46:         /* make sure stdio is set up */
   47:         if (!__sdidinit)
   48:                 __sinit();
   49: 
   50:         /*
   51:          * If we are not writing, we had better be reading and writing.
   52:          */
   53:         if ((fp->_flags & __SWR) == 0) {
   54:                 if ((fp->_flags & __SRW) == 0)
   55:                         return (EOF);
   56:                 if (fp->_flags & __SRD) {
   57:                         /* clobber any ungetc data */
   58:                         if (HASUB(fp))
   59:                                 FREEUB(fp);
   60:                         fp->_flags &= ~(__SRD|__SEOF);
   61:                         fp->_r = 0;
   62:                         fp->_p = fp->_bf._base;
   63:                 }
   64:                 fp->_flags |= __SWR;
   65:         }
   66: 
   67:         /*
   68:          * Make a buffer if necessary, then set _w.
   69:          */
   70:         if (fp->_bf._base == NULL) {
   71:                 if ((fp->_flags & (__SSTR | __SALC)) == __SSTR)
   72:                         return (EOF);
   73:                 __smakebuf(fp);
   74:         }
   75:         if (fp->_flags & __SLBF) {
   76:                 /*
   77:                  * It is line buffered, so make _lbfsize be -_bufsize
   78:                  * for the putc() macro.  We will change _lbfsize back
   79:                  * to 0 whenever we turn off __SWR.
   80:                  */
   81:                 fp->_w = 0;
   82:                 fp->_lbfsize = -fp->_bf._size;
   83:         } else
   84:                 fp->_w = fp->_flags & __SNBF ? 0 : fp->_bf._size;
   85:         return (0);
   86: }