1 /* fpending.c -- return the number of pending output bytes on a stream 2 Copyright (C) 2000, 2004, 2006-2007, 2009-2021 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 }