libio/oldiofdopen.c

   1 /* Copyright (C) 1993,94,97,99,2000,2002,2003,2004
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.
  19
  20    As a special exception, if you link the code in this file with
  21    files compiled with a GNU compiler to produce an executable,
  22    that does not cause the resulting executable to be covered by
  23    the GNU Lesser General Public License.  This exception does not
  24    however invalidate any other reasons why the executable file
  25    might be covered by the GNU Lesser General Public License.
  26    This exception applies to code released by its copyright holders
  27    in files containing the exception.  */
  28
  29 #include <shlib-compat.h>
  30 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
  31
  32 #define _IO_USE_OLD_IO_FILE
  33 #ifdef __STDC__
  34 # include <stdlib.h>
  35 #endif
  36 #include "libioP.h"
  37 #include <fcntl.h>
  38
  39 #ifndef _IO_fcntl
  40 # define _IO_fcntl __fcntl
  41 #endif
  42
  43 _IO_FILE *
  44 attribute_compat_text_section
  45 _IO_old_fdopen (fd, mode)
  46      int fd;
  47      const char *mode;
  48 {
  49   int read_write;
  50   int posix_mode = 0;
  51   struct locked_FILE
  52   {
  53     struct _IO_FILE_complete_plus fp;
  54 #ifdef _IO_MTSAFE_IO
  55     _IO_lock_t lock;
  56 #endif
  57   } *new_f;
  58   int fd_flags;
  59
  60   switch (*mode++)
  61     {
  62     case 'r':
  63       read_write = _IO_NO_WRITES;
  64       break;
  65     case 'w':
  66       read_write = _IO_NO_READS;
  67       break;
  68     case 'a':
  69       posix_mode = O_APPEND;
  70       read_write = _IO_NO_READS|_IO_IS_APPENDING;
  71       break;
  72     default:
  73       MAYBE_SET_EINVAL;
  74       return NULL;
  75   }
  76   if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
  77     read_write &= _IO_IS_APPENDING;
  78 #ifdef F_GETFL
  79   fd_flags = _IO_fcntl (fd, F_GETFL);
  80 #ifndef O_ACCMODE
  81 #define O_ACCMODE (O_RDONLY|O_WRONLY|O_RDWR)
  82 #endif
  83   if (fd_flags == -1
  84       || ((fd_flags & O_ACCMODE) == O_RDONLY && !(read_write & _IO_NO_WRITES))
  85       || ((fd_flags & O_ACCMODE) == O_WRONLY && !(read_write & _IO_NO_READS)))
  86     return NULL;
  87
  88   /* The May 93 draft of P1003.4/D14.1 (redesignated as 1003.1b)
  89      [System Application Program Interface (API) Amendment 1:
  90      Realtime Extensions], Rationale B.8.3.3
  91      Open a Stream on a File Descriptor says:
  92
  93          Although not explicitly required by POSIX.1, a good
  94          implementation of append ("a") mode would cause the
  95          O_APPEND flag to be set.
  96
  97      (Historical implementations [such as Solaris2] do a one-time
  98      seek in fdopen.)
  99
 100      However, we do not turn O_APPEND off if the mode is "w" (even
 101      though that would seem consistent) because that would be more
 102      likely to break historical programs.
 103      */
 104   if ((posix_mode & O_APPEND) && !(fd_flags & O_APPEND))
 105     {
 106 #ifdef F_SETFL
 107       if (_IO_fcntl (fd, F_SETFL, fd_flags | O_APPEND) == -1)
 108 #endif
 109         return NULL;
 110     }
 111 #endif
 112
 113   new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE));
 114   if (new_f == NULL)
 115     return NULL;
 116 #ifdef _IO_MTSAFE_IO
 117   new_f->fp.file._file._lock = &new_f->lock;
 118 #endif
 119   _IO_old_init (&new_f->fp.file._file, 0);
 120   _IO_JUMPS ((struct _IO_FILE_plus *) &new_f->fp) = &_IO_old_file_jumps;
 121   _IO_old_file_init ((struct _IO_FILE_plus *) &new_f->fp);
 122 #if  !_IO_UNIFIED_JUMPTABLES
 123   new_f->fp.vtable = NULL;
 124 #endif
 125   if (_IO_old_file_attach (&new_f->fp.file._file, fd) == NULL)
 126     {
 127       INTUSE(_IO_un_link) ((struct _IO_FILE_plus *) &new_f->fp);
 128       free (new_f);
 129       return NULL;
 130     }
 131   new_f->fp.file._file._flags &= ~_IO_DELETE_DONT_CLOSE;
 132
 133   _IO_mask_flags (&new_f->fp.file._file, read_write,
 134                   _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
 135
 136   return (_IO_FILE *) &new_f->fp;
 137 }
 138
 139 strong_alias (_IO_old_fdopen, __old_fdopen)
 140 compat_symbol (libc, _IO_old_fdopen, _IO_fdopen, GLIBC_2_0);
 141 compat_symbol (libc, __old_fdopen, fdopen, GLIBC_2_0);
 142
 143 #endif