compiler/clib/read.c

   1 /*
   2     Copyright © 1995-2012, 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 "__stdio.h"
  14 #include "__fdesc.h"
  15
  16 /*****************************************************************************
  17
  18     NAME */
  19 #include <unistd.h>
  20
  21         ssize_t read (
  22
  23 /*  SYNOPSIS */
  24         int    fd,
  25         void * buf,
  26         size_t count)
  27
  28 /*  FUNCTION
  29         Read an amount of bytes from a file descriptor.
  30
  31     INPUTS
  32         fd - The file descriptor to read from
  33         buf - The buffer to read the bytes into
  34         count - Read this many bytes.
  35
  36     RESULT
  37         The number of characters read (may range from 0 when the file
  38         descriptor contains no more characters to count) or -1 on error.
  39
  40     NOTES
  41
  42     EXAMPLE
  43
  44     BUGS
  45
  46     SEE ALSO
  47         open(), read(), fread()
  48
  49     INTERNALS
  50
  51 ******************************************************************************/
  52 {
  53     ssize_t cnt;
  54     fdesc *fdesc = __getfdesc(fd);
  55
  56     if (!fdesc)
  57     {
  58         errno = EBADF;
  59         return -1;
  60     }
  61
  62     if(fdesc->fcb->isdir)
  63     {
  64         errno = EISDIR;
  65         return -1;
  66     }
  67
  68     cnt = Read ((BPTR)fdesc->fcb->fh, buf, count);
  69
  70     if (cnt == -1)
  71         errno = __arosc_ioerr2errno (IoErr ());
  72
  73     return cnt;
  74 } /* read */
  75