usr/src/lib/libc/port/stdio/_flsbuf.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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #pragma weak __flsbuf = _flsbuf
  33
  34 #include "lint.h"
  35 #include "file64.h"
  36 #include <mtlib.h>
  37 #include <stdio.h>
  38 #include <thread.h>
  39 #include <synch.h>
  40 #include <unistd.h>
  41 #include <sys/types.h>
  42 #include "stdiom.h"
  43
  44 int
  45 _flsbuf(int ch, FILE *iop)      /* flush (write) buffer, save ch, */
  46                                 /* return EOF on failure */
  47 {
  48         Uchar uch;
  49
  50         do      /* only loop if need to use _wrtchk() on non-_IOFBF */
  51         {
  52                 switch (iop->_flag & (_IOFBF | _IOLBF | _IONBF |
  53                                 _IOWRT | _IOEOF))
  54                 {
  55                 case _IOFBF | _IOWRT:   /* okay to do full-buffered case */
  56                         if (iop->_base != 0 && iop->_ptr > iop->_base)
  57                                 goto flush_putc;        /* skip _wrtchk() */
  58                         break;
  59                 case _IOLBF | _IOWRT:   /* okay to do line-buffered case */
  60                         if (iop->_ptr >= _bufend(iop))
  61                                 /*
  62                                  * which will recursively call
  63                                  * __flsbuf via putc because of no room
  64                                  * in the buffer for the character
  65                                  */
  66                                 goto flush_putc;
  67                         if ((*iop->_ptr++ = (unsigned char)ch) == '\n')
  68                                 (void) _xflsbuf(iop);
  69                         iop->_cnt = 0;
  70                         goto out;
  71                 case _IONBF | _IOWRT:   /* okay to do no-buffered case */
  72                         iop->_cnt = 0;
  73                         uch = (unsigned char)ch;
  74                         if (write(GET_FD(iop), (char *)&uch, 1) != 1) {
  75                                 if (!cancel_active())
  76                                         iop->_flag |= _IOERR;
  77                                 return (EOF);
  78                         }
  79                         goto out;
  80                 }
  81                 if (_wrtchk(iop) != 0)  /* check, correct permissions */
  82                         return (EOF);
  83         } while (iop->_flag & (_IOLBF | _IONBF));
  84 flush_putc:
  85         (void) _xflsbuf(iop);
  86         (void) PUTC(ch, iop); /*  recursive call */
  87 out:
  88         /* necessary for putc() */
  89         return ((iop->_flag & _IOERR) ? EOF : (unsigned char)ch);
  90 }