1 /* Retrieve information about a FILE stream. 2 Copyright (C) 2007-2021 Free Software Foundation, Inc. 3 4 This file is free software: you can redistribute it and/or modify 5 it under the terms of the GNU Lesser General Public License as 6 published by the Free Software Foundation; either version 2.1 of the 7 License, or (at your option) any later version. 8 9 This file is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 #include <stddef.h> 18 #include <stdio.h> 19 20 /* Assuming the stream STREAM is open for reading: 21 Return the number of bytes waiting in the input buffer of STREAM. 22 This includes both the bytes that have been read from the underlying input 23 source and the bytes that have been pushed back through 'ungetc'. 24 25 If this number is 0 and the stream is not currently writing, 26 fflush (STREAM) is known to be a no-op. 27 28 STREAM must not be wide-character oriented. */ 29 30 #if HAVE___FREADAHEAD /* musl libc */ 31 32 # include <stdio_ext.h> 33 # define freadahead(stream) __freadahead (stream) 34 35 #else 36 37 # ifdef __cplusplus 38 extern "C" { 39 # endif 40 41 extern size_t freadahead (FILE *stream) _GL_ATTRIBUTE_PURE; 42 43 # ifdef __cplusplus 44 } 45 # endif 46 47 #endif