newlib/libc/stdio64/fdopen64.c

   1 /*
   2 FUNCTION
   3 <<fdopen64>>---turn open large file into a stream
   4
   5 INDEX
   6         fdopen64
   7 INDEX
   8         _fdopen64_r
   9
  10 SYNOPSIS
  11         #include <stdio.h>
  12         FILE *fdopen64(int <[fd]>, const char *<[mode]>);
  13         FILE *_fdopen64_r(void *<[reent]>,
  14                      int <[fd]>, const char *<[mode]>);
  15
  16 DESCRIPTION
  17 <<fdopen64>> produces a file descriptor of type <<FILE *>>, from a
  18 descriptor for an already-open file (returned, for example, by the
  19 system subroutine <<open>> rather than by <<fopen>>).
  20 The <[mode]> argument has the same meanings as in <<fopen>>.
  21
  22 RETURNS
  23 File pointer or <<NULL>>, as for <<fopen>>.
  24 */
  25
  26 #include <sys/types.h>
  27 #include <sys/fcntl.h>
  28
  29 #include <stdio.h>
  30 #include <errno.h>
  31 #include "local.h"
  32 #include <_syslist.h>
  33 #include <sys/lock.h>
  34
  35 extern int __sflags ();
  36
  37 FILE *
  38 _fdopen64_r (struct _reent *ptr,
  39         int fd,
  40         const char *mode)
  41 {
  42   register FILE *fp;
  43   int flags, oflags;
  44 #ifdef HAVE_FCNTL
  45   int fdflags, fdmode;
  46 #endif
  47
  48   if ((flags = __sflags (ptr, mode, &oflags)) == 0)
  49     return 0;
  50
  51   /* make sure the mode the user wants is a subset of the actual mode */
  52 #ifdef HAVE_FCNTL
  53   if ((fdflags = _fcntl_r (ptr, fd, F_GETFL, 0)) < 0)
  54     return 0;
  55   fdmode = fdflags & O_ACCMODE;
  56   if (fdmode != O_RDWR && (fdmode != (oflags & O_ACCMODE)))
  57     {
  58       _REENT_ERRNO(ptr) = EBADF;
  59       return 0;
  60     }
  61 #endif
  62
  63   if ((fp = __sfp (ptr)) == 0)
  64     return 0;
  65
  66   _newlib_flockfile_start(fp);
  67
  68   fp->_flags = flags;
  69   /* POSIX recommends setting the O_APPEND bit on fd to match append
  70      streams.  Someone may later clear O_APPEND on fileno(fp), but the
  71      stream must still remain in append mode.  Rely on __sflags
  72      setting __SAPP properly.  */
  73 #ifdef HAVE_FCNTL
  74   if ((oflags & O_APPEND) && !(fdflags & O_APPEND))
  75     _fcntl_r (ptr, fd, F_SETFL, fdflags | O_APPEND);
  76 #endif
  77   fp->_file = fd;
  78   fp->_cookie = (void *) fp;
  79
  80 #undef _read
  81 #undef _write
  82 #undef _seek
  83 #undef _close
  84
  85   fp->_read = __sread;
  86   fp->_write = __swrite64;
  87   fp->_seek = __sseek;
  88   fp->_seek64 = __sseek64;
  89   fp->_close = __sclose;
  90
  91 #ifdef __SCLE
  92   /* Explicit given mode results in explicit setting mode on fd */
  93   if (oflags & O_BINARY)
  94     setmode(fp->_file, O_BINARY);
  95   else if (oflags & O_TEXT)
  96     setmode(fp->_file, O_TEXT);
  97   if (__stextmode(fp->_file))
  98     fp->_flags |= __SCLE;
  99 #endif
 100
 101   fp->_flags |= __SL64;
 102
 103   _newlib_flockfile_end(fp);
 104   return fp;
 105 }
 106
 107 #ifndef _REENT_ONLY
 108
 109 FILE *
 110 fdopen64 (int fd,
 111         const char *mode)
 112 {
 113   return _fdopen64_r (_REENT, fd, mode);
 114 }
 115
 116 #endif