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