toolchain/gcc/newlib/libc/stdio/fdopen.c

   1 /*
   2 FUNCTION
   3 <<fdopen>>---turn open file into a stream
   4
   5 INDEX
   6         fdopen
   7 INDEX
   8         _fdopen_r
   9
  10 ANSI_SYNOPSIS
  11         #include <stdio.h>
  12         FILE *fdopen(int <[fd]>, const char *<[mode]>);
  13         FILE *_fdopen_r(void *<[reent]>,
  14                      int <[fd]>, const char *<[mode]>);
  15
  16 TRAD_SYNOPSIS
  17         #include <stdio.h>
  18         FILE *fdopen(<[fd]>, <[mode]>)
  19         int <[fd]>;
  20         char *<[mode]>;
  21
  22         FILE *_fdopen_r(<[reent]>, <[fd]>, <[mode]>)
  23         char *<[reent]>;
  24         int <[fd]>;
  25         char *<[mode]>);
  26
  27 DESCRIPTION
  28 <<fdopen>> produces a file descriptor of type <<FILE *>>, from a
  29 descriptor for an already-open file (returned, for example, by the
  30 system subroutine <<open>> rather than by <<fopen>>).
  31 The <[mode]> argument has the same meanings as in <<fopen>>.
  32
  33 RETURNS
  34 File pointer or <<NULL>>, as for <<fopen>>.
  35
  36 PORTABILITY
  37 <<fdopen>> is ANSI.
  38 */
  39
  40 #include <sys/types.h>
  41 #include <sys/fcntl.h>
  42
  43 #include <stdio.h>
  44 #include <errno.h>
  45 #include "local.h"
  46 #include <_syslist.h>
  47
  48 extern int __sflags ();
  49
  50 FILE *
  51 _DEFUN (_fdopen_r, (ptr, fd, mode),
  52         struct _reent *ptr _AND
  53         int fd _AND
  54         _CONST char *mode)
  55 {
  56   register FILE *fp;
  57   int flags, oflags;
  58 #ifdef HAVE_FCNTL
  59   int fdflags, fdmode;
  60 #endif
  61
  62   if ((flags = __sflags (ptr, mode, &oflags)) == 0)
  63     return 0;
  64
  65   /* make sure the mode the user wants is a subset of the actual mode */
  66 #ifdef HAVE_FCNTL
  67   if ((fdflags = _fcntl_r (ptr, fd, F_GETFL, 0)) < 0)
  68     return 0;
  69   fdmode = fdflags & O_ACCMODE;
  70   if (fdmode != O_RDWR && (fdmode != (oflags & O_ACCMODE)))
  71     {
  72       ptr->_errno = EBADF;
  73       return 0;
  74     }
  75 #endif
  76
  77   if ((fp = __sfp (ptr)) == 0)
  78     return 0;
  79   fp->_flags = flags;
  80   /*
  81    * If opened for appending, but underlying descriptor
  82    * does not have O_APPEND bit set, assert __SAPP so that
  83    * __swrite() will lseek to end before each write.
  84    */
  85   if ((oflags & O_APPEND)
  86 #ifdef HAVE_FCNTL
  87        && !(fdflags & O_APPEND)
  88 #endif
  89       )
  90     fp->_flags |= __SAPP;
  91   fp->_file = fd;
  92   fp->_cookie = (_PTR) fp;
  93
  94 #undef _read
  95 #undef _write
  96 #undef _seek
  97 #undef _close
  98
  99   fp->_read = __sread;
 100   fp->_write = __swrite;
 101   fp->_seek = __sseek;
 102   fp->_close = __sclose;
 103
 104 #ifdef __SCLE
 105   /* Explicit given mode results in explicit setting mode on fd */
 106   if (oflags & O_BINARY)
 107     setmode(fp->_file, O_BINARY);
 108   else if (oflags & O_TEXT)
 109     setmode(fp->_file, O_TEXT);
 110   if (__stextmode(fp->_file))
 111     fp->_flags |= __SCLE;
 112 #endif
 113
 114   return fp;
 115 }
 116
 117 #ifndef _REENT_ONLY
 118
 119 FILE *
 120 _DEFUN (fdopen, (fd, mode),
 121         int fd _AND
 122         _CONST char *mode)
 123 {
 124   return _fdopen_r (_REENT, fd, mode);
 125 }
 126
 127 #endif