root/lib/fpending.c

DEFINITIONS

1. __fpending

     1 /* fpending.c -- return the number of pending output bytes on a stream
     2    Copyright (C) 2000, 2004, 2006-2007, 2009-2023 Free Software Foundation,
     3    Inc.
     4 
     5    This program is free software: you can redistribute it and/or modify
     6    it under the terms of the GNU General Public License as published by
     7    the Free Software Foundation, either version 3 of the License, or
     8    (at your option) any later version.
     9 
    10    This program is distributed in the hope that it will be useful,
    11    but WITHOUT ANY WARRANTY; without even the implied warranty of
    12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13    GNU General Public License for more details.
    14 
    15    You should have received a copy of the GNU General Public License
    16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
    17 
    18 /* Written by Jim Meyering. */
    19 
    20 #include <config.h>
    21 
    22 /* Specification.  */
    23 #include "fpending.h"
    24 
    25 #include "stdio-impl.h"
    26 
    27 /* This file is not used on systems that already have the __fpending function,
    28    namely glibc >= 2.2, Solaris >= 7, UnixWare >= 7.1.4.MP4, Cygwin >= 1.7.34,
    29    Android API >= 23.  */
    30 
    31 /* Return the number of pending (aka buffered, unflushed)
    32    bytes on the stream, FP, that is open for writing.  */
    33 size_t
    34 __fpending (FILE *fp)
    35 {
    36   /* Most systems provide FILE as a struct and the necessary bitmask in
    37      <stdio.h>, because they need it for implementing getc() and putc() as
    38      fast macros.  */
    39 #if defined _IO_EOF_SEEN || defined _IO_ftrylockfile || __GNU_LIBRARY__ == 1
    40   /* GNU libc, BeOS, Haiku, Linux libc5 */
    41   return fp->_IO_write_ptr - fp->_IO_write_base;
    42 #elif defined __sferror || defined __DragonFly__ || defined __ANDROID__
    43   /* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin < 1.7.34, Minix 3, Android */
    44   return fp_->_p - fp_->_bf._base;
    45 #elif defined __EMX__                /* emx+gcc */
    46   return fp->_ptr - fp->_buffer;
    47 #elif defined __minix                /* Minix */
    48   return fp_->_ptr - fp_->_buf;
    49 #elif defined _IOERR                 /* AIX, HP-UX, IRIX, OSF/1, Solaris, OpenServer, UnixWare, mingw, MSVC, NonStop Kernel, OpenVMS */
    50   return (fp_->_ptr ? fp_->_ptr - fp_->_base : 0);
    51 #elif defined __UCLIBC__             /* uClibc */
    52   return (fp->__modeflags & __FLAG_WRITING ? fp->__bufpos - fp->__bufstart : 0);
    53 #elif defined __QNX__                /* QNX */
    54   return (fp->_Mode & 0x2000 /*_MWRITE*/ ? fp->_Next - fp->_Buf : 0);
    55 #elif defined __MINT__               /* Atari FreeMiNT */
    56   return fp->__bufp - fp->__buffer;
    57 #elif defined EPLAN9                 /* Plan9 */
    58   return fp->wp - fp->buf;
    59 #else
    60 # error "Please port gnulib fpending.c to your platform!"
    61   return 1;
    62 #endif
    63 }