usr/src/lib/libc/port/print/fprintf.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 /*
  33  * This symbol should not be defined, but there are some
  34  * miserable old compiler libraries that depend on it.
  35  */
  36 #pragma weak _fprintf = fprintf
  37
  38 #include "lint.h"
  39 #include <mtlib.h>
  40 #include <thread.h>
  41 #include <synch.h>
  42 #include <stdarg.h>
  43 #include <values.h>
  44 #include <errno.h>
  45 #include "print.h"
  46 #include <sys/types.h>
  47 #include "libc.h"
  48 #include "mse.h"
  49
  50 /*VARARGS2*/
  51 int
  52 fprintf(FILE *iop, const char *format, ...)
  53 {
  54         ssize_t count;
  55         rmutex_t *lk;
  56         va_list ap;
  57
  58         va_start(ap, format);
  59
  60         /* Use F*LOCKFILE() macros because fprintf() is not async-safe. */
  61         FLOCKFILE(lk, iop);
  62
  63         _SET_ORIENTATION_BYTE(iop);
  64
  65         if (!(iop->_flag & _IOWRT)) {
  66                 /* if no write flag */
  67                 if (iop->_flag & _IORW) {
  68                         /* if ok, cause read-write */
  69                         iop->_flag |= _IOWRT;
  70                 } else {
  71                         /* else error */
  72                         FUNLOCKFILE(lk);
  73                         errno = EBADF;
  74                         return (EOF);
  75                 }
  76         }
  77         count = _ndoprnt(format, ap, iop, 0);
  78
  79         /* return EOF on error or EOF */
  80         if (FERROR(iop) || count == EOF) {
  81                 FUNLOCKFILE(lk);
  82                 return (EOF);
  83         }
  84
  85         FUNLOCKFILE(lk);
  86
  87         /* error on overflow */
  88         if ((size_t)count > MAXINT) {
  89                 errno = EOVERFLOW;
  90                 return (EOF);
  91         }
  92         return ((int)count);
  93 }