libio/oldiofdopen.c

   1 /* Copyright (C) 1993,94,97,99,2000,2002 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.
  18
  19    As a special exception, if you link the code in this file with
  20    files compiled with a GNU compiler to produce an executable,
  21    that does not cause the resulting executable to be covered by
  22    the GNU Lesser General Public License.  This exception does not
  23    however invalidate any other reasons why the executable file
  24    might be covered by the GNU Lesser General Public License.
  25    This exception applies to code released by its copyright holders
  26    in files containing the exception.  */
  27
  28 #include <shlib-compat.h>
  29 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
  30
  31 #define _IO_USE_OLD_IO_FILE
  32 #ifdef __STDC__
  33 # include <stdlib.h>
  34 #endif
  35 #include "libioP.h"
  36 #include <fcntl.h>
  37
  38 #ifndef _IO_fcntl
  39 # define _IO_fcntl __fcntl
  40 #endif
  41
  42 _IO_FILE *
  43 _IO_old_fdopen (fd, mode)
  44      int fd;
  45      const char *mode;
  46 {
  47   int read_write;
  48   int posix_mode = 0;
  49   struct locked_FILE
  50   {
  51     struct _IO_FILE_plus fp;
  52 #ifdef _IO_MTSAFE_IO
  53     _IO_lock_t lock;
  54 #endif
  55   } *new_f;
  56   int fd_flags;
  57
  58   switch (*mode++)
  59     {
  60     case 'r':
  61       read_write = _IO_NO_WRITES;
  62       break;
  63     case 'w':
  64       read_write = _IO_NO_READS;
  65       break;
  66     case 'a':
  67       posix_mode = O_APPEND;
  68       read_write = _IO_NO_READS|_IO_IS_APPENDING;
  69       break;
  70     default:
  71       MAYBE_SET_EINVAL;
  72       return NULL;
  73   }
  74   if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
  75     read_write &= _IO_IS_APPENDING;
  76 #ifdef F_GETFL
  77   fd_flags = _IO_fcntl (fd, F_GETFL);
  78 #ifndef O_ACCMODE
  79 #define O_ACCMODE (O_RDONLY|O_WRONLY|O_RDWR)
  80 #endif
  81   if (fd_flags == -1
  82       || ((fd_flags & O_ACCMODE) == O_RDONLY && !(read_write & _IO_NO_WRITES))
  83       || ((fd_flags & O_ACCMODE) == O_WRONLY && !(read_write & _IO_NO_READS)))
  84     return NULL;
  85
  86   /* The May 93 draft of P1003.4/D14.1 (redesignated as 1003.1b)
  87      [System Application Program Interface (API) Amendment 1:
  88      Realtime Extensions], Rationale B.8.3.3
  89      Open a Stream on a File Descriptor says:
  90
  91          Although not explicitly required by POSIX.1, a good
  92          implementation of append ("a") mode would cause the
  93          O_APPEND flag to be set.
  94
  95      (Historical implementations [such as Solaris2] do a one-time
  96      seek in fdopen.)
  97
  98      However, we do not turn O_APPEND off if the mode is "w" (even
  99      though that would seem consistent) because that would be more
 100      likely to break historical programs.
 101      */
 102   if ((posix_mode & O_APPEND) && !(fd_flags & O_APPEND))
 103     {
 104 #ifdef F_SETFL
 105       if (_IO_fcntl (fd, F_SETFL, fd_flags | O_APPEND) == -1)
 106 #endif
 107         return NULL;
 108     }
 109 #endif
 110
 111   new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
 112   if (new_f == NULL)
 113     return NULL;
 114 #ifdef _IO_MTSAFE_IO
 115   new_f->fp.file._lock = &new_f->lock;
 116 #endif
 117   INTUSE(_IO_init) (&new_f->fp.file, 0);
 118   _IO_JUMPS (&new_f->fp) = &_IO_old_file_jumps;
 119   _IO_old_file_init (&new_f->fp);
 120 #if  !_IO_UNIFIED_JUMPTABLES
 121   new_f->fp.vtable = NULL;
 122 #endif
 123   if (_IO_old_file_attach (&new_f->fp.file, fd) == NULL)
 124     {
 125       INTUSE(_IO_un_link) (&new_f->fp);
 126       free (new_f);
 127       return NULL;
 128     }
 129   new_f->fp.file._flags &= ~_IO_DELETE_DONT_CLOSE;
 130
 131   new_f->fp.file._IO_file_flags =
 132     _IO_mask_flags (&new_f->fp.file, read_write,
 133                     _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
 134
 135   return (_IO_FILE *) &new_f->fp;
 136 }
 137
 138 strong_alias (_IO_old_fdopen, __old_fdopen)
 139 compat_symbol (libc, _IO_old_fdopen, _IO_fdopen, GLIBC_2_0);
 140 compat_symbol (libc, __old_fdopen, fdopen, GLIBC_2_0);
 141
 142 #endif