compiler/clib/read.c

   1 /*
   2     Copyright © 1995-2003, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     ANSI C function read().
   6 */
   7
   8 #include <errno.h>
   9 #include <dos/dos.h>
  10 #include <dos/dosextens.h>
  11 #include <proto/exec.h>
  12 #include <proto/dos.h>
  13 #include "__errno.h"
  14 #include "__stdio.h"
  15 #include "__open.h"
  16
  17 /*****************************************************************************
  18
  19     NAME */
  20 #include <unistd.h>
  21
  22         ssize_t read (
  23
  24 /*  SYNOPSIS */
  25         int    fd,
  26         void * buf,
  27         size_t count)
  28
  29 /*  FUNCTION
  30         Read an amount of bytes from a file descriptor.
  31
  32     INPUTS
  33         fd - The file descriptor to read from
  34         buf - The buffer to read the bytes into
  35         count - Read this many bytes.
  36
  37     RESULT
  38         The number of characters read (may range from 0 when the file
  39         descriptor contains no more characters to count) or -1 on error.
  40
  41     NOTES
  42
  43     EXAMPLE
  44
  45     BUGS
  46
  47     SEE ALSO
  48         open(), read(), fread()
  49
  50     INTERNALS
  51
  52 ******************************************************************************/
  53 {
  54     ssize_t cnt;
  55     fdesc *fdesc = __getfdesc(fd);
  56
  57     if (!fdesc)
  58     {
  59         errno = EBADF;
  60         return -1;
  61     }
  62
  63     if(fdesc->fcb->isdir)
  64     {
  65         errno = EISDIR;
  66         return -1;
  67     }
  68
  69     cnt = Read ((BPTR)fdesc->fcb->fh, buf, count);
  70
  71     if (cnt == -1)
  72         errno = IoErr2errno (IoErr ());
  73
  74     return cnt;
  75 } /* read */
  76