newlib/libc/stdio/rget.c

   1 /*
   2  * Copyright (c) 1990 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms are permitted
   6  * provided that the above copyright notice and this paragraph are
   7  * duplicated in all such forms and that any documentation,
   8  * and/or other materials related to such
   9  * distribution and use acknowledge that the software was developed
  10  * by the University of California, Berkeley.  The name of the
  11  * University may not be used to endorse or promote products derived
  12  * from this software without specific prior written permission.
  13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  16  */
  17 /* No user fns here. Pesch 15apr92. */
  18
  19 #if defined(LIBC_SCCS) && !defined(lint)
  20 static char sccsid[] = "%W% (Berkeley) %G%";
  21 #endif /* LIBC_SCCS and not lint */
  22
  23 #include <_ansi.h>
  24 #include <stdio.h>
  25 #include <errno.h>
  26 #include "local.h"
  27
  28 /*
  29  * Handle getc() when the buffer ran out:
  30  * Refill, then return the first character
  31  * in the newly-filled buffer.
  32  */
  33
  34 int
  35 __srget_r (struct _reent *ptr,
  36        register FILE *fp)
  37 {
  38   /* Ensure that any fake std stream is resolved before
  39      we call __srefill_r so we may access the true read buffer. */
  40   CHECK_INIT(ptr, fp);
  41
  42   /* Have to set and check orientation here, otherwise the macros in
  43      stdio.h never set it. */
  44   if (ORIENT (fp, -1) != -1)
  45     return EOF;
  46
  47   if (__srefill_r (ptr, fp) == 0)
  48     {
  49       fp->_r--;
  50       return *fp->_p++;
  51     }
  52   return EOF;
  53 }
  54
  55 /* This function isn't any longer declared in stdio.h, but it's
  56    required for backward compatibility with applications built against
  57    earlier dynamically built newlib libraries. */
  58 int
  59 __srget (register FILE *fp)
  60 {
  61   return __srget_r (_REENT, fp);
  62 }