Date: Mon, 1 Jun 1998 19:46:41 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: DJ Delorie <dj AT delorie DOT com>
cc: djgpp-workers AT delorie DOT com
Subject: fflush non-ANSI
Message-ID: <Pine.SUN.3.91.980601194505.16341I-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk

Somebody complained that fflush doesn't behave like ANSI mandates when 
its argument is a NULL pointer.  Here's a patch (and correction of a typo 
in _fwalk's docs, while I was at that):

*** src/libc/ansi/stdio/fflush.c~0	Fri Mar 22 20:14:40 1996
--- src/libc/ansi/stdio/fflush.c	Fri May 29 19:20:20 1998
***************
*** 2,7 ****
--- 2,8 ----
  /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
  #include <libc/stubs.h>
  #include <stdio.h>
+ #include <errno.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <stdlib.h>
*************** fflush(FILE *f)
*** 14,19 ****
--- 15,32 ----
  {
    char *base;
    int n, rn;
+ 
+   if (f == NULL)
+   {
+     int e = errno;
+ 
+     errno = 0;
+     _fwalk((void (*)(FILE *))fflush);
+     if (errno)
+       return EOF;
+     errno = e;
+     return 0;
+   }
  
    f->_flag &= ~_IOUNGETC;
    if ((f->_flag&(_IONBF|_IOWRT))==_IOWRT
*** src/libc/ansi/stdio/fflush.t~0	Mon Jul 10 05:39:40 1995
--- src/libc/ansi/stdio/fflush.txh	Fri May 29 19:33:00 1998
*************** int fflush(FILE *file);
*** 9,21 ****
  
  @subheading Description
  
! This function causes any unwritten buffered data to be written out to
! the given @var{file}.  This is useful in cases where the output is line
! buffered and you want to write a partial line. 
  
  @subheading Return Value
  
! Zero on success, -1 on error.
  
  @subheading Example
  
--- 9,34 ----
  
  @subheading Description
  
! If @var{file} is not a @code{NULL} pointer, this function causes any
! unwritten buffered data to be written out to the given @var{file}.  This
! is useful in cases where the output is line buffered and you want to
! write a partial line.
! 
! If @var{file} is a @code{NULL} pointer, @code{fflush} writes any
! buffered output to all files opened for output.
! 
! Note that @code{fflush} has no effect for streams opened for reading
! only.  Also note that the operating system can further buffer/cache
! writes to disk files; a call to @code{fsync} (@pxref{fsync}) or
! @code{sync} (@pxref{sync}) is typically required to actually deliver
! data to the file(s).
  
  @subheading Return Value
  
! Zero on success, -1 on error.  When called with a @code{NULL} pointer,
! -1 will be returned if an error happened while flushing some of the
! streams (but @code{fflush} will still try to flush all the rest before
! it returns).
  
  @subheading Example
  
*** src/docs/kb/wc202.~12	Sat May 23 21:08:28 1998
--- src/docs/kb/wc202.txi	Fri May 29 19:30:26 1998
***************
*** 391,393 ****
--- 391,397 ----
  call fails, this variable gets assigned the value of the error code
  returned by the failed DOS function.
  @vindex _doserrno
+ 
+ @code{fflush} now conforms to ANSI C standard when called with a
+ @code{NULL} argument.
+ @findex fflush
*** src/libc/ansi/stdio/fwalk.t~0	Sun Aug 31 20:13:18 1997
--- src/libc/ansi/stdio/fwalk.txh	Fri May 29 19:39:16 1998
***************
*** 10,16 ****
  @subheading Description
  
  For each open file in the system, the given @var{function} is called,
! passing the file pointer as it's only argument
  
  @subheading Return Value
  
--- 10,16 ----
  @subheading Description
  
  For each open file in the system, the given @var{function} is called,
! passing the file pointer as its only argument.
  
  @subheading Return Value