newlib/libc/stdio/feof.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
  18 /*
  19 FUNCTION
  20 <<feof>>, <<feof_unlocked>>---test for end of file
  21
  22 INDEX
  23         feof
  24 INDEX
  25         feof_unlocked
  26
  27 SYNOPSIS
  28         #include <stdio.h>
  29         int feof(FILE *<[fp]>);
  30
  31         #define _BSD_SOURCE
  32         #include <stdio.h>
  33         int feof_unlocked(FILE *<[fp]>);
  34
  35 DESCRIPTION
  36 <<feof>> tests whether or not the end of the file identified by <[fp]>
  37 has been reached.
  38
  39 <<feof_unlocked>> is a non-thread-safe version of <<feof>>.
  40 <<feof_unlocked>> may only safely be used within a scope
  41 protected by flockfile() (or ftrylockfile()) and funlockfile().  This
  42 function may safely be used in a multi-threaded program if and only
  43 if they are called while the invoking thread owns the (FILE *)
  44 object, as is the case after a successful call to the flockfile() or
  45 ftrylockfile() functions.  If threads are disabled, then
  46 <<feof_unlocked>> is equivalent to <<feof>>.
  47
  48 RETURNS
  49 <<feof>> returns <<0>> if the end of file has not yet been reached; if
  50 at end of file, the result is nonzero.
  51
  52 PORTABILITY
  53 <<feof>> is required by ANSI C.
  54
  55 <<feof_unlocked>> is a BSD extension also provided by GNU libc.
  56
  57 No supporting OS subroutines are required.
  58 */
  59
  60 #include <stdio.h>
  61 #include "local.h"
  62
  63 /* A subroutine version of the macro feof.  */
  64
  65 #undef feof
  66
  67 int
  68 feof (FILE * fp)
  69 {
  70   int result;
  71   CHECK_INIT(_REENT, fp);
  72   _newlib_flockfile_start (fp);
  73   result = __sfeof (fp);
  74   _newlib_flockfile_end (fp);
  75   return result;
  76 }