compiler/stdc/fread.c

   1 /*
   2     Copyright © 1995-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     C99 function fread().
   6 */
   7 #include <proto/dos.h>
   8 #include <errno.h>
   9
  10 #include "__stdio.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <stdio.h>
  16
  17         size_t fread (
  18
  19 /*  SYNOPSIS */
  20         void * restrict buf,
  21         size_t size,
  22         size_t nblocks,
  23         FILE * restrict stream)
  24
  25 /*  FUNCTION
  26         Read an amount of bytes from a stream.
  27
  28     INPUTS
  29         buf - The buffer to read the bytes into
  30         size - Size of one block to read
  31         nblocks - The number of blocks to read
  32         stream - Read from this stream
  33
  34     RESULT
  35         The number of blocks read. This may range from 0 when the stream
  36         contains no more blocks up to nblocks. In case of an error, 0 is
  37         returned.
  38
  39     NOTES
  40
  41     EXAMPLE
  42
  43     BUGS
  44
  45     SEE ALSO
  46         fopen(), fwrite()
  47
  48     INTERNALS
  49
  50 ******************************************************************************/
  51 {
  52     LONG cnt;
  53
  54     if (size == 0 || nblocks == 0)
  55         return 0;
  56
  57     if (!(stream->flags & __STDCIO_STDIO_READ))
  58     {
  59         SetIoErr(ERROR_READ_PROTECTED);
  60         errno = EACCES;
  61         stream->flags |= __STDCIO_STDIO_ERROR;
  62         return 0;
  63     }
  64
  65     cnt = FRead (stream->fh, buf, size, nblocks);
  66
  67     if (cnt == -1)
  68     {
  69         errno = __stdc_ioerr2errno (IoErr ());
  70         stream->flags |= __STDCIO_STDIO_ERROR;
  71
  72         cnt = 0;
  73     }
  74     else if (cnt < nblocks)
  75     {
  76         stream->flags |= __STDCIO_STDIO_EOF;
  77     }
  78
  79     return (size_t)cnt;
  80 } /* fread */