usr/src/lib/libbc/libc/stdio/sys5/filbuf.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1998 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*LINTLIBRARY*/
  33 #include <stdio.h>
  34 #include <unistd.h>
  35
  36 extern void     _findbuf();
  37
  38 static void     lbfflush(FILE *);
  39
  40 int
  41 __filbuf(FILE *iop)
  42 {
  43         return (_filbuf(iop));
  44 }
  45
  46 int
  47 _filbuf(FILE *iop)
  48 {
  49         if ( !(iop->_flag & _IOREAD) )
  50                 if (iop->_flag & _IORW)
  51                         iop->_flag |= _IOREAD;
  52                 else
  53                         return(EOF);
  54
  55         if (iop->_flag&_IOSTRG)
  56                 return(EOF);
  57
  58         if (iop->_base == NULL)  /* get buffer if we don't have one */
  59                 _findbuf(iop);
  60
  61         /* if this device is a terminal (line-buffered) or unbuffered, then */
  62         /* flush buffers of all line-buffered devices currently writing */
  63
  64         if (iop->_flag & (_IOLBF | _IONBF))
  65                 _fwalk(lbfflush);
  66
  67         iop->_ptr = iop->_base;
  68         iop->_cnt = read(fileno(iop), (char *)iop->_base,
  69             (unsigned)((iop->_flag & _IONBF) ? 1 : iop->_bufsiz ));
  70         if (--iop->_cnt >= 0)           /* success */
  71                 return (*iop->_ptr++);
  72         if (iop->_cnt != -1)            /* error */
  73                 iop->_flag |= _IOERR;
  74         else {                          /* end-of-file */
  75                 iop->_flag |= _IOEOF;
  76                 if (iop->_flag & _IORW)
  77                         iop->_flag &= ~_IOREAD;
  78         }
  79         iop->_cnt = 0;
  80         return (EOF);
  81 }
  82
  83 static void
  84 lbfflush(FILE *iop)
  85 {
  86         if (iop->_flag & _IOLBF)
  87                 (void) fflush(iop);
  88 }