usr/src/lib/libc/port/stdio/fdopen.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  * Unix routine to do an "fopen" on file descriptor
  34  * The mode has to be repeated because you can't query its
  35  * status
  36  */
  37
  38 #define _LARGEFILE64_SOURCE 1
  39
  40 #pragma weak _fdopen = fdopen
  41
  42 #include "lint.h"
  43 #include <mtlib.h>
  44 #include "file64.h"
  45 #include <sys/types.h>
  46 #include <unistd.h>
  47 #include <stdio.h>
  48 #include <limits.h>
  49 #include <thread.h>
  50 #include <synch.h>
  51 #include "stdiom.h"
  52 #include <errno.h>
  53 #include <fcntl.h>
  54
  55 FILE *
  56 fdopen(int fd, const char *type) /* associate file desc. with stream */
  57 {
  58         /* iop doesn't need locking since this function is creating it */
  59         FILE *iop;
  60         char plus;
  61         unsigned char flag;
  62
  63         /* Sets EBADF for bad fds */
  64         if (fcntl(fd, F_GETFD) == -1)
  65                 return (NULL);
  66
  67         if ((iop = _findiop()) == 0) {
  68                 errno = ENOMEM;
  69                 return (NULL);
  70         }
  71
  72         switch (type[0]) {
  73         default:
  74                 iop->_flag = 0; /* release iop */
  75                 errno = EINVAL;
  76                 return (NULL);
  77         case 'r':
  78                 flag = _IOREAD;
  79                 break;
  80         case 'a':
  81                 (void) lseek64(fd, (off64_t)0, SEEK_END);
  82                 /*FALLTHROUGH*/
  83         case 'w':
  84                 flag = _IOWRT;
  85                 break;
  86         }
  87         if ((plus = type[1]) == 'b')    /* Unix ignores 'b' ANSI std */
  88                 plus = type[2];
  89         if (plus == '+')
  90                 flag = _IORW;
  91         iop->_flag = flag;
  92
  93 #ifdef  _LP64
  94         iop->_file = fd;
  95 #else
  96         if (fd <= _FILE_FD_MAX) {
  97                 SET_FILE(iop, fd);
  98         } else if (_file_set(iop, fd, type) != 0) {
  99                 /* errno set by _file_set () */
 100                 iop->_flag = 0;         /* release iop */
 101                 return (NULL);
 102         }
 103 #endif  /*      _LP64   */
 104
 105         return (iop);
 106 }